Merge branch 'blender2.8' into hair_guides

This is needed for allowing variable length hair strands, where the hair index can not
simply be calculated from the vertex index based on a fixed-length strand.

intern/cycles/blender/blender_curves.cpp

@@ -110,95 +110,342 @@ static void InterpolateKeySegments(int seg,
 		curveinterp_v3_v3v3v3v3(keyloc, &ckey_loc1, &ckey_loc2, &ckey_loc3, &ckey_loc4, t);
 }
 
-static bool ObtainCacheParticleData(Mesh *mesh,
-                                    BL::Mesh *b_mesh,
-                                    BL::Object *b_ob,
-                                    ParticleCurveData *CData,
-                                    bool background)
+static void ObtainCacheDataFromParticleSystem(Mesh *mesh,
+                                              BL::Object *b_ob,
+                                              BL::ParticleSystemModifier *b_psmd,
+                                              ParticleCurveData *CData,
+                                              bool background,
+                                              int *curvenum,
+                                              int *keyno)
 {
-	int curvenum = 0;
-	int keyno = 0;
-
-	if(!(mesh && b_mesh && b_ob && CData))
-		return false;
+	BL::ParticleSystem b_psys((const PointerRNA)b_psmd->particle_system().ptr);
+	BL::ParticleSettings b_part((const PointerRNA)b_psys.settings().ptr);
 
 	Transform tfm = get_transform(b_ob->matrix_world());
 	Transform itfm = transform_quick_inverse(tfm);
 
+	if((b_part.type() != BL::ParticleSettings::type_HAIR) ||
+	   (b_part.render_type() != BL::ParticleSettings::render_type_PATH))
+	{
+		return;
+	}
+	
+	int shader = clamp(b_part.material()-1, 0, mesh->used_shaders.size()-1);
+	int draw_step = background ? b_part.render_step() : b_part.draw_step();
+	int totparts = b_psys.particles.length();
+	int totchild = background ? b_psys.child_particles.length() : (int)((float)b_psys.child_particles.length() * (float)b_part.draw_percentage() / 100.0f);
+	int totcurves = totchild;
+	
+	if(b_part.child_type() == 0 || totchild == 0)
+		totcurves += totparts;
+	
+	if(totcurves == 0)
+		return;
+	
+	int ren_step = (1 << draw_step) + 1;
+	if(b_part.kink() == BL::ParticleSettings::kink_SPIRAL)
+		ren_step += b_part.kink_extra_steps();
+	
+	CData->psys_firstcurve.push_back_slow(*curvenum);
+	CData->psys_curvenum.push_back_slow(totcurves);
+	CData->psys_shader.push_back_slow(shader);
+	
+	float radius = b_part.radius_scale() * 0.5f;
+	
+	CData->psys_rootradius.push_back_slow(radius * b_part.root_radius());
+	CData->psys_tipradius.push_back_slow(radius * b_part.tip_radius());
+	CData->psys_shape.push_back_slow(b_part.shape());
+	CData->psys_closetip.push_back_slow(b_part.use_close_tip());
+	
+	int pa_no = 0;
+	if(!(b_part.child_type() == 0) && totchild != 0)
+		pa_no = totparts;
+	
+	int num_add = (totparts+totchild - pa_no);
+	CData->curve_firstkey.reserve(CData->curve_firstkey.size() + num_add);
+	CData->curve_keynum.reserve(CData->curve_keynum.size() + num_add);
+	CData->curve_length.reserve(CData->curve_length.size() + num_add);
+	CData->curvekey_co.reserve(CData->curvekey_co.size() + num_add*ren_step);
+	CData->curvekey_time.reserve(CData->curvekey_time.size() + num_add*ren_step);
+	
+	for(; pa_no < totparts+totchild; pa_no++) {
+		int keynum = 0;
+		CData->curve_firstkey.push_back_slow(*keyno);
+		
+		float curve_length = 0.0f;
+		float3 pcKey;
+		for(int step_no = 0; step_no < ren_step; step_no++) {
+			float nco[3];
+			b_psys.co_hair(*b_ob, pa_no, step_no, nco);
+			float3 cKey = make_float3(nco[0], nco[1], nco[2]);
+			cKey = transform_point(&itfm, cKey);
+			if(step_no > 0) {
+				float step_length = len(cKey - pcKey);
+				if(step_length == 0.0f)
+					continue;
+				curve_length += step_length;
+			}
+			CData->curvekey_co.push_back_slow(cKey);
+			CData->curvekey_time.push_back_slow(curve_length);
+			pcKey = cKey;
+			keynum++;
+		}
+		*keyno += keynum;
+		
+		CData->curve_keynum.push_back_slow(keynum);
+		CData->curve_length.push_back_slow(curve_length);
+		(*curvenum)++;
+	}
+}
+
+static void ObtainCacheUVFromParticleSystem(BL::Mesh *b_mesh,
+                                            BL::ParticleSystemModifier *b_psmd,
+                                            ParticleCurveData *CData,
+                                            bool background,
+                                            int uv_num)
+{
+	BL::ParticleSystem b_psys((const PointerRNA)b_psmd->particle_system().ptr);
+	BL::ParticleSettings b_part((const PointerRNA)b_psys.settings().ptr);
+
+	if((b_part.type() != BL::ParticleSettings::type_HAIR) ||
+	   (b_part.render_type() != BL::ParticleSettings::render_type_PATH))
+	{
+		return;
+	}
+
+	int totparts = b_psys.particles.length();
+	int totchild = background ? b_psys.child_particles.length() : (int)((float)b_psys.child_particles.length() * (float)b_part.draw_percentage() / 100.0f);
+	int totcurves = totchild;
+	
+	if(b_part.child_type() == 0 || totchild == 0)
+		totcurves += totparts;
+	
+	if(totcurves == 0)
+		return;
+	
+	int pa_no = 0;
+	if(!(b_part.child_type() == 0) && totchild != 0)
+		pa_no = totparts;
+	
+	int num_add = (totparts+totchild - pa_no);
+	CData->curve_uv.reserve(CData->curve_uv.size() + num_add);
+	
+	BL::ParticleSystem::particles_iterator b_pa;
+	b_psys.particles.begin(b_pa);
+	for(; pa_no < totparts+totchild; pa_no++) {
+		/* Add UVs */
+		BL::Mesh::tessface_uv_textures_iterator l;
+		b_mesh->tessface_uv_textures.begin(l);
+		
+		float3 uv = make_float3(0.0f, 0.0f, 0.0f);
+		if(b_mesh->tessface_uv_textures.length())
+			b_psys.uv_on_emitter(*b_psmd, *b_pa, pa_no, uv_num, &uv.x);
+		CData->curve_uv.push_back_slow(uv);
+		
+		if(pa_no < totparts && b_pa != b_psys.particles.end())
+			++b_pa;
+	}
+}
+
+static void ObtainCacheVColFromParticleSystem(BL::Mesh *b_mesh,
+                                              BL::ParticleSystemModifier *b_psmd,
+                                              ParticleCurveData *CData,
+                                              bool background,
+                                              int vcol_num)
+{
+	BL::ParticleSystem b_psys((const PointerRNA)b_psmd->particle_system().ptr);
+	BL::ParticleSettings b_part((const PointerRNA)b_psys.settings().ptr);
+
+	if((b_part.type() != BL::ParticleSettings::type_HAIR) ||
+	   (b_part.render_type() != BL::ParticleSettings::render_type_PATH))
+	{
+		return;
+	}
+
+	int totparts = b_psys.particles.length();
+	int totchild = background ? b_psys.child_particles.length() : (int)((float)b_psys.child_particles.length() * (float)b_part.draw_percentage() / 100.0f);
+	int totcurves = totchild;
+	
+	if(b_part.child_type() == 0 || totchild == 0)
+		totcurves += totparts;
+	
+	if(totcurves == 0)
+		return;
+	
+	int pa_no = 0;
+	if(!(b_part.child_type() == 0) && totchild != 0)
+		pa_no = totparts;
+	
+	int num_add = (totparts+totchild - pa_no);
+	CData->curve_vcol.reserve(CData->curve_vcol.size() + num_add);
+	
+	BL::ParticleSystem::particles_iterator b_pa;
+	b_psys.particles.begin(b_pa);
+	for(; pa_no < totparts+totchild; pa_no++) {
+		/* Add vertex colors */
+		BL::Mesh::tessface_vertex_colors_iterator l;
+		b_mesh->tessface_vertex_colors.begin(l);
+		
+		float3 vcol = make_float3(0.0f, 0.0f, 0.0f);
+		if(b_mesh->tessface_vertex_colors.length())
+			b_psys.mcol_on_emitter(*b_psmd, *b_pa, pa_no, vcol_num, &vcol.x);
+		CData->curve_vcol.push_back_slow(vcol);
+		
+		if(pa_no < totparts && b_pa != b_psys.particles.end())
+			++b_pa;
+	}
+}
+
+static void ObtainCacheDataFromHairSystem(BL::Object *b_ob,
+                                          BL::HairSystem *b_hsys,
+                                          BL::Mesh *b_scalp,
+                                          int shader,
+                                          bool /*background*/,
+                                          ParticleCurveData *CData,
+                                          int *curvenum,
+                                          int *keyno)
+{
+	Transform tfm = get_transform(b_ob->matrix_world());
+	Transform itfm = transform_quick_inverse(tfm);
+	
+	void *hair_cache = BKE_hair_export_cache_new();
+	BKE_hair_export_cache_update(hair_cache, b_hsys->ptr.data, 0, b_scalp->ptr.data, 0xFFFFFFFF);
+	
+	int totcurves, totverts;
+	BKE_hair_render_get_buffer_size(hair_cache, &totcurves, &totverts);
+	
+	if(totcurves == 0)
+	{
+		BKE_hair_export_cache_free(hair_cache);
+		return;
+	}
+	
+	CData->psys_firstcurve.push_back_slow(*curvenum);
+	CData->psys_curvenum.push_back_slow(totcurves);
+	
+	// Material
+	CData->psys_shader.push_back_slow(shader);
+	
+	{
+		// Cycles settings
+//		PointerRNA cpsys = RNA_pointer_get(&b_hsys->ptr, "cycles");
+//		float radius = get_float(cpsys, "radius_scale") * 0.5f;
+//		CData->psys_rootradius.push_back_slow(radius * get_float(cpsys, "root_width"));
+//		CData->psys_tipradius.push_back_slow(radius * get_float(cpsys, "tip_width"));
+//		CData->psys_shape.push_back_slow(get_float(cpsys, "shape"));
+//		CData->psys_closetip.push_back_slow(get_boolean(cpsys, "use_closetip"));
+		float radius = 0.01f * 0.5f;
+		CData->psys_rootradius.push_back_slow(radius * 1.0f);
+		CData->psys_tipradius.push_back_slow(radius * 0.0f);
+		CData->psys_shape.push_back_slow(0.0f);
+		CData->psys_closetip.push_back_slow(true);
+	}
+	
+	// Allocate buffers
+	int *firstkey_data;
+	int *keynum_data;
+	float *length_data;
+	float3 *co_data;
+	float *time_data;
+	{
+		const size_t firstkey_start = CData->curve_firstkey.size();
+		const size_t keynum_start = CData->curve_keynum.size();
+		const size_t length_start = CData->curve_length.size();
+		const size_t co_start = CData->curvekey_co.size();
+		const size_t time_start = CData->curvekey_time.size();
+		CData->curve_firstkey.resize(firstkey_start + totcurves);
+		CData->curve_keynum.resize(keynum_start + totcurves);
+		CData->curve_length.resize(length_start + totcurves);
+		CData->curvekey_co.resize(co_start + totverts);
+		CData->curvekey_time.resize(time_start + totverts);
+		firstkey_data = CData->curve_firstkey.data() + firstkey_start;
+		keynum_data = CData->curve_keynum.data() + keynum_start;
+		length_data = CData->curve_length.data() + length_start;
+		co_data = CData->curvekey_co.data() + co_start;
+		time_data = CData->curvekey_time.data() + time_start;
+	}
+	
+	// Import render curves from hair system
+	BKE_hair_render_fill_buffers(
+	            hair_cache,
+	            (int)sizeof(float3),
+	            firstkey_data,
+	            keynum_data,
+	            (float*)co_data);
+	
+	// Compute curve length and key times
+	for(int c = 0; c < totcurves; ++c) {
+		const int firstkey = firstkey_data[c];
+		const int keynum = keynum_data[c];
+		
+		float curve_length = 0.0f;
+		float3 pcKey;
+		for(int v = 0; v < keynum; v++) {
+			float3 cKey = co_data[firstkey + v];
+			cKey = transform_point(&itfm, cKey);
+			if(v > 0) {
+				float step_length = len(cKey - pcKey);
+				if(step_length == 0.0f)
+					continue;
+				curve_length += step_length;
+			}
+			
+			co_data[firstkey + v] = cKey;
+			time_data[v] = curve_length;
+			pcKey = cKey;
+		}
+		
+		firstkey_data[c] = *keyno;
+		length_data[c] = curve_length;
+		*keyno += keynum;
+	}
+	*curvenum += totcurves;
+	
+	BKE_hair_export_cache_free(hair_cache);
+}
+
+static bool ObtainCacheDataFromObject(Mesh *mesh,
+                                      BL::Object *b_ob,
+                                      ParticleCurveData *CData,
+                                      bool background)
+{
+	int curvenum = 0;
+	int keyno = 0;
+
+	if(!(mesh && b_ob && CData))
+		return false;
+
 	BL::Object::modifiers_iterator b_mod;
 	for(b_ob->modifiers.begin(b_mod); b_mod != b_ob->modifiers.end(); ++b_mod) {
-		if((b_mod->type() == b_mod->type_PARTICLE_SYSTEM) && (background ? b_mod->show_render() : b_mod->show_viewport())) {
-			BL::ParticleSystemModifier psmd((const PointerRNA)b_mod->ptr);
-			BL::ParticleSystem b_psys((const PointerRNA)psmd.particle_system().ptr);
-			BL::ParticleSettings b_part((const PointerRNA)b_psys.settings().ptr);
-
-			if((b_part.render_type() == BL::ParticleSettings::render_type_PATH) && (b_part.type() == BL::ParticleSettings::type_HAIR)) {
-				int shader = clamp(b_part.material()-1, 0, mesh->used_shaders.size()-1);
-				int draw_step = background ? b_part.render_step() : b_part.draw_step();
-				int totparts = b_psys.particles.length();
-				int totchild = background ? b_psys.child_particles.length() : (int)((float)b_psys.child_particles.length() * (float)b_part.draw_percentage() / 100.0f);
-				int totcurves = totchild;
-
-				if(b_part.child_type() == 0 || totchild == 0)
-					totcurves += totparts;
-
-				if(totcurves == 0)
-					continue;
-
-				int ren_step = (1 << draw_step) + 1;
-				if(b_part.kink() == BL::ParticleSettings::kink_SPIRAL)
-					ren_step += b_part.kink_extra_steps();
-
-				CData->psys_firstcurve.push_back_slow(curvenum);
-				CData->psys_curvenum.push_back_slow(totcurves);
-				CData->psys_shader.push_back_slow(shader);
-
-				float radius = b_part.radius_scale() * 0.5f;
-
-				CData->psys_rootradius.push_back_slow(radius * b_part.root_radius());
-				CData->psys_tipradius.push_back_slow(radius * b_part.tip_radius());
-				CData->psys_shape.push_back_slow(b_part.shape());
-				CData->psys_closetip.push_back_slow(b_part.use_close_tip());
-
-				int pa_no = 0;
-				if(!(b_part.child_type() == 0) && totchild != 0)
-					pa_no = totparts;
-
-				int num_add = (totparts+totchild - pa_no);
-				CData->curve_firstkey.reserve(CData->curve_firstkey.size() + num_add);
-				CData->curve_keynum.reserve(CData->curve_keynum.size() + num_add);
-				CData->curve_length.reserve(CData->curve_length.size() + num_add);
-				CData->curvekey_co.reserve(CData->curvekey_co.size() + num_add*ren_step);
-				CData->curvekey_time.reserve(CData->curvekey_time.size() + num_add*ren_step);
-
-				for(; pa_no < totparts+totchild; pa_no++) {
-					int keynum = 0;
-					CData->curve_firstkey.push_back_slow(keyno);
-
-					float curve_length = 0.0f;
-					float3 pcKey;
-					for(int step_no = 0; step_no < ren_step; step_no++) {
-						float nco[3];
-						b_psys.co_hair(*b_ob, pa_no, step_no, nco);
-						float3 cKey = make_float3(nco[0], nco[1], nco[2]);
-						cKey = transform_point(&itfm, cKey);
-						if(step_no > 0) {
-							float step_length = len(cKey - pcKey);
-							if(step_length == 0.0f)
-								continue;
-							curve_length += step_length;
-						}
-						CData->curvekey_co.push_back_slow(cKey);
-						CData->curvekey_time.push_back_slow(curve_length);
-						pcKey = cKey;
-						keynum++;
-					}
-					keyno += keynum;
-
-					CData->curve_keynum.push_back_slow(keynum);
-					CData->curve_length.push_back_slow(curve_length);
-					curvenum++;
-				}
+		if (background ? b_mod->show_render() : b_mod->show_viewport())
+		{
+			if((b_mod->type() == b_mod->type_PARTICLE_SYSTEM)) {
+				BL::ParticleSystemModifier b_psmd((const PointerRNA)b_mod->ptr);
+				ObtainCacheDataFromParticleSystem(mesh,
+				                                  b_ob,
+				                                  &b_psmd,
+				                                  CData,
+				                                  background,
+				                                  &curvenum,
+				                                  &keyno);
+			}
+			if((b_mod->type() == b_mod->type_HAIR)) {
+				BL::HairModifier b_hmd((const PointerRNA)b_mod->ptr);
+				BL::HairSystem b_hsys = b_hmd.hair_system();
+				
+				const int material_index = 1; /* TODO */
+				int shader = clamp(material_index - 1, 0, mesh->used_shaders.size()-1);
+				
+				BL::Mesh b_scalp(b_ob->data());
+				
+				ObtainCacheDataFromHairSystem(b_ob,
+				                              &b_hsys,
+				                              &b_scalp,
+				                              shader,
+				                              background,
+				                              CData,
+				                              &curvenum,
+				                              &keyno);
 			}
 		}
 	}
@@ -206,12 +453,12 @@ static bool ObtainCacheParticleData(Mesh *mesh,
 	return true;
 }
 
-static bool ObtainCacheParticleUV(Mesh *mesh,
-                                  BL::Mesh *b_mesh,
-                                  BL::Object *b_ob,
-                                  ParticleCurveData *CData,
-                                  bool background,
-                                  int uv_num)
+static bool ObtainCacheUVFromObject(Mesh *mesh,
+                                    BL::Mesh *b_mesh,
+                                    BL::Object *b_ob,
+                                    ParticleCurveData *CData,
+                                    bool background,
+                                    int uv_num)
 {
 	if(!(mesh && b_mesh && b_ob && CData))
 		return false;
@@ -220,44 +467,11 @@ static bool ObtainCacheParticleUV(Mesh *mesh,
 
 	BL::Object::modifiers_iterator b_mod;
 	for(b_ob->modifiers.begin(b_mod); b_mod != b_ob->modifiers.end(); ++b_mod) {
-		if((b_mod->type() == b_mod->type_PARTICLE_SYSTEM) && (background ? b_mod->show_render() : b_mod->show_viewport())) {
-			BL::ParticleSystemModifier psmd((const PointerRNA)b_mod->ptr);
-			BL::ParticleSystem b_psys((const PointerRNA)psmd.particle_system().ptr);
-			BL::ParticleSettings b_part((const PointerRNA)b_psys.settings().ptr);
-
-			if((b_part.render_type() == BL::ParticleSettings::render_type_PATH) && (b_part.type() == BL::ParticleSettings::type_HAIR)) {
-				int totparts = b_psys.particles.length();
-				int totchild = background ? b_psys.child_particles.length() : (int)((float)b_psys.child_particles.length() * (float)b_part.draw_percentage() / 100.0f);
-				int totcurves = totchild;
-
-				if(b_part.child_type() == 0 || totchild == 0)
-					totcurves += totparts;
-
-				if(totcurves == 0)
-					continue;
-
-				int pa_no = 0;
-				if(!(b_part.child_type() == 0) && totchild != 0)
-					pa_no = totparts;
-
-				int num_add = (totparts+totchild - pa_no);
-				CData->curve_uv.reserve(CData->curve_uv.size() + num_add);
-
-				BL::ParticleSystem::particles_iterator b_pa;
-				b_psys.particles.begin(b_pa);
-				for(; pa_no < totparts+totchild; pa_no++) {
-					/* Add UVs */
-					BL::Mesh::tessface_uv_textures_iterator l;
-					b_mesh->tessface_uv_textures.begin(l);
-
-					float3 uv = make_float3(0.0f, 0.0f, 0.0f);
-					if(b_mesh->tessface_uv_textures.length())
-						b_psys.uv_on_emitter(psmd, *b_pa, pa_no, uv_num, &uv.x);
-					CData->curve_uv.push_back_slow(uv);
-
-					if(pa_no < totparts && b_pa != b_psys.particles.end())
-						++b_pa;
-				}
+		if (background ? b_mod->show_render() : b_mod->show_viewport())
+		{
+			if((b_mod->type() == b_mod->type_PARTICLE_SYSTEM)) {
+				BL::ParticleSystemModifier b_psmd((const PointerRNA)b_mod->ptr);
+				ObtainCacheUVFromParticleSystem(b_mesh, &b_psmd, CData, background, uv_num);
 			}
 		}
 	}
@@ -265,12 +479,12 @@ static bool ObtainCacheParticleUV(Mesh *mesh,
 	return true;
 }
 
-static bool ObtainCacheParticleVcol(Mesh *mesh,
-                                    BL::Mesh *b_mesh,
-                                    BL::Object *b_ob,
-                                    ParticleCurveData *CData,
-                                    bool background,
-                                    int vcol_num)
+static bool ObtainCacheVcolFromObject(Mesh *mesh,
+                                      BL::Mesh *b_mesh,
+                                      BL::Object *b_ob,
+                                      ParticleCurveData *CData,
+                                      bool background,
+                                      int vcol_num)
 {
 	if(!(mesh && b_mesh && b_ob && CData))
 		return false;
@@ -279,44 +493,12 @@ static bool ObtainCacheParticleVcol(Mesh *mesh,
 
 	BL::Object::modifiers_iterator b_mod;
 	for(b_ob->modifiers.begin(b_mod); b_mod != b_ob->modifiers.end(); ++b_mod) {
-		if((b_mod->type() == b_mod->type_PARTICLE_SYSTEM) && (background ? b_mod->show_render() : b_mod->show_viewport())) {
-			BL::ParticleSystemModifier psmd((const PointerRNA)b_mod->ptr);
-			BL::ParticleSystem b_psys((const PointerRNA)psmd.particle_system().ptr);
-			BL::ParticleSettings b_part((const PointerRNA)b_psys.settings().ptr);
-
-			if((b_part.render_type() == BL::ParticleSettings::render_type_PATH) && (b_part.type() == BL::ParticleSettings::type_HAIR)) {
-				int totparts = b_psys.particles.length();
-				int totchild = background ? b_psys.child_particles.length() : (int)((float)b_psys.child_particles.length() * (float)b_part.draw_percentage() / 100.0f);
-				int totcurves = totchild;
-
-				if(b_part.child_type() == 0 || totchild == 0)
-					totcurves += totparts;
-
-				if(totcurves == 0)
-					continue;
-
-				int pa_no = 0;
-				if(!(b_part.child_type() == 0) && totchild != 0)
-					pa_no = totparts;
-
-				int num_add = (totparts+totchild - pa_no);
-				CData->curve_vcol.reserve(CData->curve_vcol.size() + num_add);
-
-				BL::ParticleSystem::particles_iterator b_pa;
-				b_psys.particles.begin(b_pa);
-				for(; pa_no < totparts+totchild; pa_no++) {
-					/* Add vertex colors */
-					BL::Mesh::tessface_vertex_colors_iterator l;
-					b_mesh->tessface_vertex_colors.begin(l);
-
-					float3 vcol = make_float3(0.0f, 0.0f, 0.0f);
-					if(b_mesh->tessface_vertex_colors.length())
-						b_psys.mcol_on_emitter(psmd, *b_pa, pa_no, vcol_num, &vcol.x);
-					CData->curve_vcol.push_back_slow(vcol);
-
-					if(pa_no < totparts && b_pa != b_psys.particles.end())
-						++b_pa;
-				}
+		if (background ? b_mod->show_render() : b_mod->show_viewport())
+		{
+			if((b_mod->type() == b_mod->type_PARTICLE_SYSTEM))
+			{
+				BL::ParticleSystemModifier b_psmd((const PointerRNA)b_mod->ptr);
+				ObtainCacheVColFromParticleSystem(b_mesh, &b_psmd, CData, background, vcol_num);
 			}
 		}
 	}
@@ -906,7 +1088,7 @@ void BlenderSync::sync_curves(Mesh *mesh,
 
 	ParticleCurveData CData;
 
-	ObtainCacheParticleData(mesh, &b_mesh, &b_ob, &CData, !preview);
+	ObtainCacheDataFromObject(mesh, &b_ob, &CData, !preview);
 
 	/* add hair geometry to mesh */
 	if(primitive == CURVE_TRIANGLES) {
@@ -942,7 +1124,7 @@ void BlenderSync::sync_curves(Mesh *mesh,
 
 	/* generated coordinates from first key. we should ideally get this from
 	 * blender to handle deforming objects */
-	if(!motion) {
+	if(b_mesh && !motion) {
 		if(mesh->need_attribute(scene, ATTR_STD_GENERATED)) {
 			float3 loc, size;
 			mesh_texture_space(b_mesh, loc, size);
@@ -967,7 +1149,7 @@ void BlenderSync::sync_curves(Mesh *mesh,
 	}
 
 	/* create vertex color attributes */
-	if(!motion) {
+	if(b_mesh && !motion) {
 		BL::Mesh::tessface_vertex_colors_iterator l;
 		int vcol_num = 0;
 
@@ -975,7 +1157,7 @@ void BlenderSync::sync_curves(Mesh *mesh,
 			if(!mesh->need_attribute(scene, ustring(l->name().c_str())))
 				continue;
 
-			ObtainCacheParticleVcol(mesh, &b_mesh, &b_ob, &CData, !preview, vcol_num);
+			ObtainCacheVcolFromObject(mesh, &b_mesh, &b_ob, &CData, !preview, vcol_num);
 
 			if(primitive == CURVE_TRIANGLES) {
 				Attribute *attr_vcol = mesh->attributes.add(
@@ -1004,7 +1186,7 @@ void BlenderSync::sync_curves(Mesh *mesh,
 	}
 
 	/* create UV attributes */
-	if(!motion) {
+	if(b_mesh && !motion) {
 		BL::Mesh::tessface_uv_textures_iterator l;
 		int uv_num = 0;
 
@@ -1017,7 +1199,7 @@ void BlenderSync::sync_curves(Mesh *mesh,
 			if(mesh->need_attribute(scene, name) || mesh->need_attribute(scene, std)) {
 				Attribute *attr_uv;
 
-				ObtainCacheParticleUV(mesh, &b_mesh, &b_ob, &CData, !preview, uv_num);
+				ObtainCacheUVFromObject(mesh, &b_mesh, &b_ob, &CData, !preview, uv_num);
 
 				if(primitive == CURVE_TRIANGLES) {
 					if(active_render)

intern/cycles/blender/blender_mesh.cpp

@@ -1188,10 +1188,12 @@ Mesh *BlenderSync::sync_mesh(BL::Depsgraph& b_depsgraph,
 
 				create_mesh_volume_attributes(scene, b_ob, mesh, b_scene.frame_current());
 			}
+		}
 
-			if(view_layer.use_hair && mesh->subdivision_type == Mesh::SUBDIVISION_NONE)
-				sync_curves(mesh, b_mesh, b_ob, false);
+		if(view_layer.use_hair && mesh->subdivision_type == Mesh::SUBDIVISION_NONE)
+			sync_curves(mesh, b_mesh, b_ob, false);
 
+		if(b_mesh) {
 			/* free derived mesh */
 			b_data.meshes.remove(b_mesh, false, true, false);
 		}

intern/cycles/blender/blender_util.h

@@ -36,6 +36,11 @@ void BKE_image_user_frame_calc(void *iuser, int cfra, int fieldnr);
 void BKE_image_user_file_path(void *iuser, void *ima, char *path);
 unsigned char *BKE_image_get_pixels_for_frame(void *image, int frame);
 float *BKE_image_get_float_pixels_for_frame(void *image, int frame);
+void* BKE_hair_export_cache_new(void);
+int BKE_hair_export_cache_update(void *cache, const void *hsys, int subdiv, void *scalp, int requested_data);
+void BKE_hair_export_cache_free(void *hcache);
+void BKE_hair_render_get_buffer_size(void* hcache, int *r_totcurves, int *r_totverts);
+void BKE_hair_render_fill_buffers(void* hcache, int vertco_stride, int *r_curvestart, int *r_curvelen, float *r_vertco);
 }
 
 CCL_NAMESPACE_BEGIN

release/scripts/startup/bl_ui/__init__.py

@@ -44,6 +44,7 @@ _modules = [
     "properties_data_lightprobe",
     "properties_data_speaker",
     "properties_data_workspace",
+    "properties_hair_common",
     "properties_mask_common",
     "properties_material",
     "properties_material_gpencil",

release/scripts/startup/bl_ui/properties_data_modifier.py

@@ -20,7 +20,7 @@
 import bpy
 from bpy.types import Panel
 from bpy.app.translations import pgettext_iface as iface_
-
+from .properties_hair_common import draw_hair_display_settings
 
 class ModifierButtonsPanel:
     bl_space_type = 'PROPERTIES'
@@ -1577,6 +1577,27 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
         if md.rest_source == 'BIND':
             layout.operator("object.correctivesmooth_bind", text="Unbind" if is_bind else "Bind")
 
+    def HAIR(self, layout, ob, md):
+        hsys = md.hair_system
+
+        split = layout.split()
+
+        col = split.column()
+        col.label("Follicles:")
+        col.prop(md, "follicle_seed")
+        col.prop(md, "follicle_count")
+        col.operator("object.hair_generate_follicles", text="Generate")
+
+        col = split.column()
+
+        col.separator()
+
+        col.prop(hsys, "material_slot", text="")
+
+        col = layout.column()
+        col.label("Display Settings:")
+        draw_hair_display_settings(col, md.draw_settings)
+
     def WEIGHTED_NORMAL(self, layout, ob, md):
         layout.label("Weighting Mode:")
         split = layout.split(align=True)

release/scripts/startup/bl_ui/properties_hair_common.py

@@ -0,0 +1,61 @@
+# ##### BEGIN GPL LICENSE BLOCK #####
+#
+#  This program is free software; you can redistribute it and/or
+#  modify it under the terms of the GNU General Public License
+#  as published by the Free Software Foundation; either version 2
+#  of the License, or (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# ##### END GPL LICENSE BLOCK #####
+
+# <pep8-80 compliant>
+
+import bpy
+
+
+def draw_hair_display_settings(layout, settings):
+    col = layout.column(align=True)
+    col.label("Follicles:")
+    col.prop(settings, "follicle_mode", expand=True)
+
+    col = layout.column(align=True)
+    col.label("Guide Curves:")
+    col.prop(settings, "guide_mode", expand=True)
+
+    layout.prop(settings, "shape")
+
+    col = layout.column(align=True)
+    col.prop(settings, "root_radius")
+    col.prop(settings, "tip_radius")
+
+    col = layout.column()
+    col.prop(settings, "radius_scale")
+    col.prop(settings, "use_close_tip")
+
+
+class HAIR_PT_display_settings:
+    # subclasses must define...
+    # ~ bl_space_type = 'PROPERTIES'
+    # ~ bl_region_type = 'WINDOW'
+    bl_label = "Hair Display Settings"
+
+    def draw(self, context):
+        settings = context.draw_hair_display_settings
+        draw_hair_display_settings(self.layout, hair_display_settings)
+
+
+classes = (
+)
+
+if __name__ == "__main__":  # only for live edit.
+    from bpy.utils import register_class
+    for cls in classes:
+        register_class(cls)

release/scripts/startup/bl_ui/space_view3d_toolbar.py

@@ -78,7 +78,6 @@ def is_not_gpencil_edit_mode(context):
     )
     return not is_gpmode
 
-
 # ********** default tools for editmode_mesh ****************
 
 

source/blender/CMakeLists.txt

@@ -49,6 +49,7 @@ set(SRC_DNA_INC
 	${CMAKE_CURRENT_SOURCE_DIR}/makesdna/DNA_shader_fx_types.h
 	${CMAKE_CURRENT_SOURCE_DIR}/makesdna/DNA_gpu_types.h
 	${CMAKE_CURRENT_SOURCE_DIR}/makesdna/DNA_group_types.h
+	${CMAKE_CURRENT_SOURCE_DIR}/makesdna/DNA_hair_types.h
 	${CMAKE_CURRENT_SOURCE_DIR}/makesdna/DNA_image_types.h
 	${CMAKE_CURRENT_SOURCE_DIR}/makesdna/DNA_ipo_types.h
 	${CMAKE_CURRENT_SOURCE_DIR}/makesdna/DNA_key_types.h

source/blender/blenkernel/BKE_hair.h

@@ -0,0 +1,238 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) Blender Foundation
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): Lukas Toenne
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#ifndef __BKE_HAIR_H__
+#define __BKE_HAIR_H__
+
+/** \file blender/blenkernel/BKE_hair.h
+ *  \ingroup bke
+ */
+
+#include "BLI_utildefines.h"
+
+static const unsigned int HAIR_CURVE_INDEX_NONE = 0xFFFFFFFF;
+
+struct HairFollicle;
+struct HairPattern;
+struct HairSystem;
+struct HairDrawSettings;
+struct HairCurveData;
+struct Mesh;
+struct MeshSample;
+struct MLoop;
+struct Object;
+
+/* Create a new hair system instance */
+struct HairSystem* BKE_hair_new(void);
+/* Copy an existing hair system */
+struct HairSystem* BKE_hair_copy(struct HairSystem *hsys);
+/* Delete a hair system */
+void BKE_hair_free(struct HairSystem *hsys);
+
+/* === Fiber curves === */
+
+/* Allocate buffers for defining fiber curves
+ * \param totcurves Number of fiber curves to allocate
+ */
+void BKE_hair_fiber_curves_begin(struct HairSystem *hsys, int totcurves);
+
+/* Set properties of a fiber curve
+ * \param index Index of the fiber curve
+ * \param mesh_sample Origin of the fiber curve on the scalp mesh.
+ * \param numverts Number of vertices in this fiber curve
+ */
+void BKE_hair_set_fiber_curve(struct HairSystem *hsys, int index, int numverts,
+                              float taper_length, float taper_thickness);
+
+/* Finalize fiber curve update */
+void BKE_hair_fiber_curves_end(struct HairSystem *hsys);
+
+/* Set properties of a fiber curve vertex
+ * \param index Index of the fiber curve vertex.
+ * \param flag Flags to set on the vertex.
+ * \param co Location of the vertex in object space.
+ */
+void BKE_hair_set_fiber_vertex(struct HairSystem *hsys, int index, int flag, const float co[3]);
+
+/* Set the hair fiber curve data used by the hair system.
+ */
+void BKE_hair_set_fiber_curves(struct HairSystem *hsys, struct HairCurveData *curves);
+
+/* Remove all fiber curves.
+ */
+void BKE_hair_clear_fiber_curves(struct HairSystem *hsys);
+
+/* === Follicles === */
+
+/* Calculate surface area of a scalp mesh */
+float BKE_hair_calc_surface_area(const struct Mesh *scalp);
+
+/* Calculate a density value based on surface area and sample count */
+float BKE_hair_calc_density_from_count(float area, int count);
+/* Calculate maximum sample count based on surface area and density */
+int BKE_hair_calc_max_count_from_density(float area, float density);
+
+/* Calculate a density value based on a minimum distance */
+float BKE_hair_calc_density_from_min_distance(float min_distance);
+/* Calculate a minimum distance based on density */
+float BKE_hair_calc_min_distance_from_density(float density);
+
+/* Distribute hair follicles on a scalp mesh */
+void BKE_hair_generate_follicles(
+        struct HairSystem* hsys,
+        struct Mesh *scalp,
+        unsigned int seed,
+        int count);
+
+/* Distribute hair follicles on a scalp mesh.
+ * Optional per-loop weights control follicle density on the scalp.
+ */
+void BKE_hair_generate_follicles_ex(
+        struct HairSystem* hsys,
+        struct Mesh *scalp,
+        unsigned int seed,
+        int count,
+        const float *loop_weights);
+
+bool BKE_hair_bind_follicles(struct HairSystem *hsys, const struct Mesh *scalp);
+
+/* === Draw Settings === */
+
+struct HairDrawSettings* BKE_hair_draw_settings_new(void);
+struct HairDrawSettings* BKE_hair_draw_settings_copy(struct HairDrawSettings *draw_settings);
+void BKE_hair_draw_settings_free(struct HairDrawSettings *draw_settings);
+
+/* === Export === */
+
+/* Intermediate data for export */
+typedef struct HairExportCache
+{
+	/* Per fiber curve data */
+	int totcurves;
+	struct HairFiberCurve *fiber_curves;
+	
+	/* Per fiber vertex data */
+	int totverts;
+	struct HairFiberVertex *fiber_verts;
+	float (*fiber_tangents)[3];             /* Tangent vectors on fiber curves */
+	float (*fiber_normals)[3];              /* Normal vectors on fiber curves */
+	
+	/* Per follicle data */
+	int totfollicles;
+	float (*follicle_root_position)[3];     /* Root position of each follicle */
+	const struct HairFollicle *follicles;
+} HairExportCache;
+
+/* Identifiers for data stored in hair export caches */
+typedef enum eHairExportCacheUpdateFlags
+{
+	/* Follicle placement on the scalp mesh */
+	HAIR_EXPORT_FOLLICLE_ROOT_POSITIONS      = (1 << 0),
+	/* Follicle curve index */
+	HAIR_EXPORT_FOLLICLE_BINDING        = (1 << 1),
+	/* Fiber vertex positions (deform only) */
+	HAIR_EXPORT_FIBER_VERTICES          = (1 << 2),
+	/* Fiber curve number and vertex counts (topology changes) */
+	HAIR_EXPORT_FIBER_CURVES            = (1 << 3),
+	
+	HAIR_EXPORT_ALL                     =
+	    HAIR_EXPORT_FOLLICLE_ROOT_POSITIONS |
+	    HAIR_EXPORT_FOLLICLE_BINDING |
+	    HAIR_EXPORT_FIBER_VERTICES |
+	    HAIR_EXPORT_FIBER_CURVES,
+	HAIR_EXPORT_FIBERS                  =
+	    HAIR_EXPORT_FIBER_VERTICES |
+	    HAIR_EXPORT_FIBER_CURVES,
+	HAIR_EXPORT_FOLLICLES               =
+	    HAIR_EXPORT_FOLLICLE_ROOT_POSITIONS |
+	    HAIR_EXPORT_FOLLICLE_BINDING,
+} eHairExportCacheUpdateFlags;
+
+/* Create a new export cache.
+ * This can be used to construct full fiber data for rendering.
+ */
+struct HairExportCache* BKE_hair_export_cache_new(void);
+
+/* Update an existing export cache to ensure it contains the requested data.
+ * Returns flags for data that has been updated.
+ */
+int BKE_hair_export_cache_update(struct HairExportCache *cache, const struct HairSystem *hsys,
+                                 int subdiv, struct Mesh *scalp, int requested_data);
+
+/* Free the given export cache */
+void BKE_hair_export_cache_free(struct HairExportCache *cache);
+
+/* Invalidate all data in a hair export cache */
+void BKE_hair_export_cache_clear(struct HairExportCache *cache);
+
+/* Invalidate part of the data in a hair export cache.
+ *
+ * Note some parts may get invalidated automatically based on internal dependencies.
+ */
+void BKE_hair_export_cache_invalidate(struct HairExportCache *cache, int invalidate);
+
+/* === Draw Cache === */
+
+enum {
+	BKE_HAIR_BATCH_DIRTY_FIBERS = (1 << 0),
+	BKE_HAIR_BATCH_DIRTY_STRANDS = (1 << 1),
+	BKE_HAIR_BATCH_DIRTY_ALL = 0xFFFF,
+};
+void BKE_hair_batch_cache_dirty(struct HairSystem* hsys, int mode);
+void BKE_hair_batch_cache_free(struct HairSystem* hsys);
+
+void BKE_hair_get_texture_buffer_size(
+        const struct HairExportCache *cache,
+        int *r_size,
+        int *r_strand_map_start,
+        int *r_strand_vertex_start,
+        int *r_fiber_start);
+void BKE_hair_get_texture_buffer(
+        const struct HairExportCache *cache,
+        void *texbuffer);
+
+/* === Render API === */
+
+/* Calculate required size for render buffers. */
+void BKE_hair_render_get_buffer_size(
+        const struct HairExportCache* cache,
+        int subdiv,
+        int *r_totcurves,
+        int *r_totverts);
+
+/* Create render data in existing buffers.
+ * Buffers must be large enough according to BKE_hair_get_render_buffer_size.
+ */
+void BKE_hair_render_fill_buffers(
+        const struct HairExportCache* cache,
+        int subdiv,
+        int vertco_stride,
+        int *r_curvestart,
+        int *r_curvelen,
+        float *r_vertco);
+
+#endif

source/blender/blenkernel/BKE_mesh_sample.h

@@ -0,0 +1,116 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#ifndef __BKE_MESH_SAMPLE_H__
+#define __BKE_MESH_SAMPLE_H__
+
+/** \file BKE_mesh_sample.h
+ *  \ingroup bke
+ */
+
+struct Mesh;
+struct Key;
+struct KeyBlock;
+struct Mesh;
+struct MFace;
+struct MVert;
+struct MPoly;
+
+struct MeshSample;
+struct MeshSampleGenerator;
+
+typedef struct MeshSampleGenerator MeshSampleGenerator;
+
+typedef void* (*MeshSampleThreadContextCreateFp)(void *userdata, int start);
+typedef void (*MeshSampleThreadContextFreeFp)(void *userdata, void *thread_ctx);
+typedef bool (*MeshSampleRayFp)(void *userdata, void *thread_ctx, float ray_start[3], float ray_end[3]);
+
+/* ==== Utility Functions ==== */
+
+float* BKE_mesh_sample_calc_triangle_weights(struct Mesh *mesh, const float *loop_weights, float *r_area);
+
+void BKE_mesh_sample_weights_from_loc(struct MeshSample *sample, struct Mesh *mesh, int looptri_index, const float loc[3]);
+
+
+/* ==== Evaluate ==== */
+
+bool BKE_mesh_sample_is_valid(const struct MeshSample *sample);
+bool BKE_mesh_sample_is_volume_sample(const struct MeshSample *sample);
+
+/* Evaluate position and normal on the given mesh */
+bool BKE_mesh_sample_eval(const struct Mesh *mesh, const struct MeshSample *sample, float loc[3], float nor[3], float tang[3]);
+
+/* Evaluate position for the given shapekey */
+bool BKE_mesh_sample_shapekey(struct Key *key, struct KeyBlock *kb, const struct MeshSample *sample, float loc[3]);
+
+void BKE_mesh_sample_clear(struct MeshSample *sample);
+
+
+/* ==== Generator Types ==== */
+
+struct MeshSampleGenerator *BKE_mesh_sample_gen_surface_vertices(void);
+
+/* vertex_weight_cb is optional */
+struct MeshSampleGenerator *BKE_mesh_sample_gen_surface_random(unsigned int seed, bool use_area_weight, const float *loop_weights);
+
+struct MeshSampleGenerator *BKE_mesh_sample_gen_surface_raycast(
+        MeshSampleThreadContextCreateFp thread_context_create_cb,
+        MeshSampleThreadContextFreeFp thread_context_free_cb,
+        MeshSampleRayFp ray_cb,
+        void *userdata);
+
+struct MeshSampleGenerator *BKE_mesh_sample_gen_surface_poissondisk(unsigned int seed, float mindist, unsigned int max_samples, const float *loop_weights);
+
+struct MeshSampleGenerator *BKE_mesh_sample_gen_volume_random_bbray(unsigned int seed, float density);
+
+void BKE_mesh_sample_free_generator(struct MeshSampleGenerator *gen);
+
+
+/* ==== Sampling ==== */
+
+void BKE_mesh_sample_generator_bind(struct MeshSampleGenerator *gen, struct Mesh *mesh);
+void BKE_mesh_sample_generator_unbind(struct MeshSampleGenerator *gen);
+
+unsigned int BKE_mesh_sample_gen_get_max_samples(const struct MeshSampleGenerator *gen);
+
+/* Generate a single sample.
+ * Not threadsafe!
+ */
+bool BKE_mesh_sample_generate(struct MeshSampleGenerator *gen, struct MeshSample *sample);
+
+/* Generate a large number of samples.
+ */
+int BKE_mesh_sample_generate_batch_ex(struct MeshSampleGenerator *gen,
+                                      void *output_buffer, int output_stride, int count,
+                                      bool use_threads);
+
+int BKE_mesh_sample_generate_batch(struct MeshSampleGenerator *gen,
+                                   MeshSample *output_buffer, int count);
+
+/* ==== Utilities ==== */
+
+struct ParticleSystem;
+struct ParticleData;
+struct BVHTreeFromMesh;
+
+bool BKE_mesh_sample_from_particle(struct MeshSample *sample, struct ParticleSystem *psys, struct Mesh *mesh, struct ParticleData *pa);
+bool BKE_mesh_sample_to_particle(struct MeshSample *sample, struct ParticleSystem *psys, struct Mesh *mesh, struct BVHTreeFromMesh *bvhtree, struct ParticleData *pa);
+
+#endif  /* __BKE_MESH_SAMPLE_H__ */

source/blender/blenkernel/BKE_particle.h

@@ -50,6 +50,7 @@ struct Main;
 struct Object;
 struct Scene;
 struct Depsgraph;
+struct Mesh;
 struct ModifierData;
 struct MTFace;
 struct MCol;
@@ -433,6 +434,7 @@ void psys_interpolate_face(struct MVert *mvert, struct MFace *mface, struct MTFa
                            float orco[3]);
 float psys_particle_value_from_verts(struct Mesh *mesh, short from, struct ParticleData *pa, float *values);
 void psys_get_from_key(struct ParticleKey *key, float loc[3], float vel[3], float rot[4], float *time);
+int psys_get_index_on_mesh(struct ParticleSystem *psys, struct Mesh *mesh, ParticleData *pa, int *mapindex, float mapfw[4]);
 
 /* BLI_bvhtree_ray_cast callback */
 void BKE_psys_collision_neartest_cb(void *userdata, int index, const struct BVHTreeRay *ray, struct BVHTreeRayHit *hit);

source/blender/blenkernel/CMakeLists.txt

@@ -118,6 +118,8 @@ set(SRC
 	intern/freestyle.c
 	intern/gpencil.c
 	intern/gpencil_modifier.c
+	intern/hair.c
+	intern/hair_draw.c
 	intern/icons.c
 	intern/icons_rasterize.c
 	intern/idcode.c
@@ -149,6 +151,7 @@ set(SRC
 	intern/mesh_merge.c
 	intern/mesh_remap.c
 	intern/mesh_runtime.c
+	intern/mesh_sample.c
 	intern/mesh_tangent.c
 	intern/mesh_validate.c
 	intern/modifier.c
@@ -264,6 +267,7 @@ set(SRC
 	BKE_global.h
 	BKE_gpencil.h
 	BKE_gpencil_modifier.h
+	BKE_hair.h
 	BKE_icons.h
 	BKE_idcode.h
 	BKE_idprop.h
@@ -288,6 +292,7 @@ set(SRC
 	BKE_mesh_mapping.h
 	BKE_mesh_remap.h
 	BKE_mesh_runtime.h
+	BKE_mesh_sample.h
 	BKE_mesh_tangent.h
 	BKE_modifier.h
 	BKE_movieclip.h

source/blender/blenkernel/intern/hair.c

@@ -0,0 +1,721 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) Blender Foundation
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): Lukas Toenne
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/blenkernel/intern/hair.c
+ *  \ingroup bke
+ */
+
+#include <limits.h>
+#include <string.h>
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_kdtree.h"
+#include "BLI_listbase.h"
+#include "BLI_math.h"
+#include "BLI_rand.h"
+#include "BLI_sort.h"
+#include "BLI_string_utf8.h"
+#include "BLI_string_utils.h"
+
+#include "DNA_hair_types.h"
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+#include "DNA_object_types.h"
+
+#include "BKE_hair.h"
+#include "BKE_library.h"
+#include "BKE_mesh.h"
+#include "BKE_mesh_sample.h"
+
+#include "BLT_translation.h"
+
+HairSystem* BKE_hair_new(void)
+{
+	HairSystem *hair = MEM_callocN(sizeof(HairSystem), "hair system");
+	
+	hair->pattern = MEM_callocN(sizeof(HairPattern), "hair pattern");
+	
+	return hair;
+}
+
+HairSystem* BKE_hair_copy(HairSystem *hsys)
+{
+	HairSystem *nhsys = MEM_dupallocN(hsys);
+	
+	if (hsys->pattern)
+	{
+		nhsys->pattern = MEM_dupallocN(hsys->pattern);
+		nhsys->pattern->follicles = MEM_dupallocN(hsys->pattern->follicles);
+	}
+	
+	if (hsys->curve_data.curves)
+	{
+		nhsys->curve_data.curves = MEM_dupallocN(hsys->curve_data.curves);
+	}
+	if (hsys->curve_data.verts)
+	{
+		nhsys->curve_data.verts = MEM_dupallocN(hsys->curve_data.verts);
+	}
+	
+	nhsys->draw_batch_cache = NULL;
+	nhsys->draw_texture_cache = NULL;
+	
+	return nhsys;
+}
+
+void BKE_hair_free(HairSystem *hsys)
+{
+	BKE_hair_batch_cache_free(hsys);
+	
+	if (hsys->curve_data.curves)
+	{
+		MEM_freeN(hsys->curve_data.curves);
+	}
+	if (hsys->curve_data.verts)
+	{
+		MEM_freeN(hsys->curve_data.verts);
+	}
+	
+	if (hsys->pattern)
+	{
+		if (hsys->pattern->follicles)
+		{
+			MEM_freeN(hsys->pattern->follicles);
+		}
+		MEM_freeN(hsys->pattern);
+	}
+	
+	MEM_freeN(hsys);
+}
+
+/* Calculate surface area of a scalp mesh */
+float BKE_hair_calc_surface_area(const Mesh *scalp)
+{
+	BLI_assert(scalp != NULL);
+	
+	int numpolys = scalp->totpoly;
+	MPoly *mpolys = scalp->mpoly;
+	MLoop *mloops = scalp->mloop;
+	MVert *mverts = scalp->mvert;
+
+	float area = 0.0f;
+	for (int i = 0; i < numpolys; ++i)
+	{
+		area += BKE_mesh_calc_poly_area(&mpolys[i], mloops + mpolys[i].loopstart, mverts);
+	}
+	return area;
+}
+
+/* Calculate a density value based on surface area and sample count */
+float BKE_hair_calc_density_from_count(float area, int count)
+{
+	return area > 0.0f ? count / area : 0.0f;
+}
+
+/* Calculate maximum sample count based on surface area and density */
+int BKE_hair_calc_max_count_from_density(float area, float density)
+{
+	return (int)(density * area);
+}
+
+/* Calculate a density value based on a minimum distance */
+float BKE_hair_calc_density_from_min_distance(float min_distance)
+{
+	// max. circle packing density (sans pi factor): 1 / (2 * sqrt(3))
+	static const float max_factor = 0.288675135;
+	
+	return min_distance > 0.0f ? max_factor / (min_distance * min_distance) : 0.0f;
+}
+
+/* Calculate a minimum distance based on density */
+float BKE_hair_calc_min_distance_from_density(float density)
+{
+	// max. circle packing density (sans pi factor): 1 / (2 * sqrt(3))
+	static const float max_factor = 0.288675135;
+	
+	return density > 0.0f ? sqrt(max_factor / density) : 0.0f;
+}
+
+/* Distribute hair follicles on a scalp mesh */
+void BKE_hair_generate_follicles(
+        HairSystem* hsys,
+        struct Mesh *scalp,
+        unsigned int seed,
+        int count)
+{
+	BKE_hair_generate_follicles_ex(hsys, scalp, seed, count, NULL);
+}
+
+/* Distribute hair follicles on a scalp mesh.
+ * Optional per-loop weights control follicle density on the scalp.
+ */
+void BKE_hair_generate_follicles_ex(
+        HairSystem* hsys,
+        struct Mesh *scalp,
+        unsigned int seed,
+        int count,
+        const float *loop_weights)
+{
+	HairPattern *pattern = hsys->pattern;
+	
+	// Limit max_count to theoretical limit based on area
+	float scalp_area = BKE_hair_calc_surface_area(scalp);
+	float density = BKE_hair_calc_density_from_count(scalp_area, count);
+	float min_distance = BKE_hair_calc_min_distance_from_density(density);
+	
+	if (pattern->follicles)
+	{
+		MEM_freeN(pattern->follicles);
+	}
+	pattern->follicles = MEM_callocN(sizeof(HairFollicle) * count, "hair follicles");
+	
+	{
+		MeshSampleGenerator *gen = BKE_mesh_sample_gen_surface_poissondisk(seed, min_distance, count, loop_weights);
+		
+		BKE_mesh_sample_generator_bind(gen, scalp);
+		
+		static const bool use_threads = false;
+		pattern->num_follicles = BKE_mesh_sample_generate_batch_ex(
+		            gen,
+		            &pattern->follicles->mesh_sample,
+		            sizeof(HairFollicle),
+		            count,
+		            use_threads);
+		
+		BKE_mesh_sample_free_generator(gen);
+	}
+	
+	hsys->flag |= HAIR_SYSTEM_UPDATE_FOLLICLE_BINDING;
+	BKE_hair_batch_cache_dirty(hsys, BKE_HAIR_BATCH_DIRTY_ALL);
+}
+
+/* ================================= */
+
+void BKE_hair_fiber_curves_begin(HairSystem *hsys, int totcurves)
+{
+	if (totcurves != hsys->curve_data.totcurves)
+	{
+		hsys->curve_data.curves = MEM_reallocN(hsys->curve_data.curves, sizeof(HairFiberCurve) * totcurves);
+		hsys->curve_data.totcurves = totcurves;
+
+		hsys->flag |= HAIR_SYSTEM_UPDATE_FOLLICLE_BINDING;
+		BKE_hair_batch_cache_dirty(hsys, BKE_HAIR_BATCH_DIRTY_ALL);
+	}
+}
+
+void BKE_hair_set_fiber_curve(HairSystem *hsys, int index, int numverts,
+                              float taper_length, float taper_thickness)
+{
+	BLI_assert(index <= hsys->curve_data.totcurves);
+	
+	HairFiberCurve *curve = &hsys->curve_data.curves[index];
+	curve->numverts = numverts;
+	curve->taper_length = taper_length;
+	curve->taper_thickness = taper_thickness;
+	
+	hsys->flag |= HAIR_SYSTEM_UPDATE_FOLLICLE_BINDING;
+	BKE_hair_batch_cache_dirty(hsys, BKE_HAIR_BATCH_DIRTY_ALL);
+}
+
+/* Calculate vertex start indices on all curves based on length.
+ * Returns the total number of vertices.
+ */
+static int hair_curve_calc_vertstart(HairSystem *hsys)
+{
+	/* Recalculate vertex count and start offsets in curves */
+	int vertstart = 0;
+	for (int i = 0; i < hsys->curve_data.totcurves; ++i)
+	{
+		hsys->curve_data.curves[i].vertstart = vertstart;
+		vertstart += hsys->curve_data.curves[i].numverts;
+	}
+	
+	return vertstart;
+}
+
+void BKE_hair_fiber_curves_end(HairSystem *hsys)
+{
+	const int totverts = hair_curve_calc_vertstart(hsys);
+
+	if (totverts != hsys->curve_data.totverts)
+	{
+		hsys->curve_data.verts = MEM_reallocN(hsys->curve_data.verts, sizeof(HairFiberVertex) * totverts);
+		hsys->curve_data.totverts = totverts;
+
+		BKE_hair_batch_cache_dirty(hsys, BKE_HAIR_BATCH_DIRTY_ALL);
+	}
+}
+
+void BKE_hair_set_fiber_vertex(HairSystem *hsys, int index, int flag, const float co[3])
+{
+	BLI_assert(index <= hsys->curve_data.totverts);
+	
+	HairFiberVertex *vertex = &hsys->curve_data.verts[index];
+	vertex->flag = flag;
+	copy_v3_v3(vertex->co, co);
+	
+	BKE_hair_batch_cache_dirty(hsys, BKE_HAIR_BATCH_DIRTY_ALL);
+}
+
+void BKE_hair_set_fiber_curves(HairSystem *hsys, HairCurveData *curves)
+{
+	if (hsys->curve_data.curves)
+	{
+		MEM_freeN(hsys->curve_data.curves);
+	}
+	hsys->curve_data.curves = MEM_dupallocN(hsys->curve_data.curves);
+	hsys->curve_data.totcurves = curves->totcurves;
+
+	if (hsys->curve_data.verts)
+	{
+		MEM_freeN(hsys->curve_data.verts);
+	}
+	hsys->curve_data.verts = MEM_dupallocN(hsys->curve_data.verts);
+	hsys->curve_data.totverts = curves->totverts;
+
+#ifndef NDEBUG
+	const int vertcount = hair_curve_calc_vertstart(hsys);
+	BLI_assert(vertcount <= hsys->curve_data.totverts);
+#endif
+
+	hsys->flag |= HAIR_SYSTEM_UPDATE_FOLLICLE_BINDING;
+	BKE_hair_batch_cache_dirty(hsys, BKE_HAIR_BATCH_DIRTY_ALL);
+}
+
+void BKE_hair_clear_fiber_curves(HairSystem *hsys)
+{
+	if (hsys->curve_data.curves)
+	{
+		MEM_freeN(hsys->curve_data.curves);
+		hsys->curve_data.curves = NULL;
+	}
+	hsys->curve_data.totcurves = 0;
+
+	if (hsys->curve_data.verts)
+	{
+		MEM_freeN(hsys->curve_data.verts);
+		hsys->curve_data.verts = NULL;
+	}
+	hsys->curve_data.totverts = 0;
+
+	hsys->flag &= ~HAIR_SYSTEM_UPDATE_FOLLICLE_BINDING;
+	BKE_hair_batch_cache_dirty(hsys, BKE_HAIR_BATCH_DIRTY_ALL);
+}
+
+/* ================================= */
+
+bool BKE_hair_bind_follicles(HairSystem *hsys, const Mesh *scalp)
+{
+	if (!(hsys->flag & HAIR_SYSTEM_UPDATE_FOLLICLE_BINDING))
+	{
+		return true;
+	}
+	hsys->flag &= ~HAIR_SYSTEM_UPDATE_FOLLICLE_BINDING;
+	
+	HairPattern *pattern = hsys->pattern;
+	if (!pattern)
+	{
+		return true;
+	}
+	
+	const int num_strands = hsys->curve_data.totcurves;
+	/* Need at least one curve for binding */
+	if (num_strands == 0)
+	{
+		HairFollicle *follicle = pattern->follicles;
+		for (int i = 0; i < pattern->num_follicles; ++i, ++follicle)
+		{
+			for (int k = 0; k < 4; ++k)
+			{
+				follicle->curve = HAIR_CURVE_INDEX_NONE;
+			}
+		}
+		return false;
+	}
+	
+	KDTree *tree = BLI_kdtree_new(num_strands);
+	for (int c = 0; c < num_strands; ++c)
+	{
+		const int vertstart = hsys->curve_data.curves[c].vertstart;
+		const float *rootco = hsys->curve_data.verts[vertstart].co;
+		BLI_kdtree_insert(tree, c, rootco);
+	}
+	BLI_kdtree_balance(tree);
+	
+	{
+		HairFollicle *follicle = pattern->follicles;
+		for (int i = 0; i < pattern->num_follicles; ++i, ++follicle)
+		{
+			float loc[3], nor[3], tang[3];
+			if (BKE_mesh_sample_eval(scalp, &follicle->mesh_sample, loc, nor, tang))
+			{
+				follicle->curve = BLI_kdtree_find_nearest(tree, loc, NULL);
+			}
+		}
+	}
+	
+	BLI_kdtree_free(tree);
+	
+	return true;
+}
+
+/* === Export === */
+
+/* Returns number of vertices in a curve after subdivision */
+BLI_INLINE int hair_get_strand_subdiv_length(int orig_length, int subdiv)
+{
+	return ((orig_length - 1) << subdiv) + 1;
+}
+
+/* Returns total number of vertices after subdivision */
+BLI_INLINE int hair_get_strand_subdiv_numverts(int numstrands, int numverts, int subdiv)
+{
+	return ((numverts - numstrands) << subdiv) + numstrands;
+}
+
+/* Subdivide a curve */
+static int hair_curve_subdivide(const HairFiberCurve* curve, const HairFiberVertex* verts,
+                                int subdiv, HairFiberVertex *r_verts)
+{
+	{
+		/* Move vertex positions from the dense array to their initial configuration for subdivision.
+		 * Also add offset to ensure the curve starts on the scalp surface.
+		 */
+		const int step = (1 << subdiv);
+		BLI_assert(curve->numverts > 0);
+		
+		HairFiberVertex *dst = r_verts;
+		for (int i = 0; i < curve->numverts; ++i) {
+			copy_v3_v3(dst->co, verts[i].co);
+			dst += step;
+		}
+	}
+	
+	/* Subdivide */
+	for (int d = 0; d < subdiv; ++d) {
+		const int num_edges = (curve->numverts - 1) << d;
+		const int hstep = 1 << (subdiv - d - 1);
+		const int step = 1 << (subdiv - d);
+		
+		/* Calculate edge points */
+		{
+			int index = 0;
+			for (int k = 0; k < num_edges; ++k, index += step) {
+				add_v3_v3v3(r_verts[index + hstep].co, r_verts[index].co, r_verts[index + step].co);
+				mul_v3_fl(r_verts[index + hstep].co, 0.5f);
+			}
+		}
+		
+		/* Move original points */
+		{
+			int index = step;
+			for (int k = 1; k < num_edges; ++k, index += step) {
+				add_v3_v3v3(r_verts[index].co, r_verts[index - hstep].co, r_verts[index + hstep].co);
+				mul_v3_fl(r_verts[index].co, 0.5f);
+			}
+		}
+	}
+	
+	const int num_verts = ((curve->numverts - 1) << subdiv) + 1;
+	return num_verts;
+}
+
+/* Calculate tangent and normal vector changes from one segment to the next */
+static void hair_curve_transport_frame(const float co1[3], const float co2[3],
+                                       float prev_tang[3], float prev_nor[3],
+                                       float r_tang[3], float r_nor[3])
+{
+	/* segment direction */
+	sub_v3_v3v3(r_tang, co2, co1);
+	normalize_v3(r_tang);
+	
+	/* rotate the frame */
+	float rot[3][3];
+	rotation_between_vecs_to_mat3(rot, prev_tang, r_tang);
+	mul_v3_m3v3(r_nor, rot, prev_nor);
+	
+	copy_v3_v3(prev_tang, r_tang);
+	copy_v3_v3(prev_nor, r_nor);
+}
+
+/* Calculate tangent and normal vectors for all vertices on a curve */
+static void hair_curve_calc_vectors(const HairFiberVertex* verts, int numverts,
+                                    float (*r_tangents)[3], float (*r_normals)[3])
+{
+	BLI_assert(numverts >= 2);
+	
+	float prev_tang[3] = {0.0f, 0.0f, 1.0f};
+	float prev_nor[3] = {1.0f, 0.0f, 0.0f};
+	
+	hair_curve_transport_frame(
+	        verts[0].co, verts[1].co,
+	        prev_tang, prev_nor,
+	        r_tangents[0], r_normals[0]);
+	
+	for (int i = 1; i < numverts - 1; ++i)
+	{
+		hair_curve_transport_frame(
+		        verts[i-1].co, verts[i+1].co,
+		        prev_tang, prev_nor,
+		        r_tangents[i], r_normals[i]);
+	}
+	
+	hair_curve_transport_frame(
+	        verts[numverts-2].co, verts[numverts-1].co,
+	        prev_tang, prev_nor,
+	        r_tangents[numverts-1], r_normals[numverts-1]);
+}
+
+/* Create a new export cache.
+ * This can be used to construct full fiber data for rendering.
+ */
+
+HairExportCache* BKE_hair_export_cache_new(void)
+{
+	HairExportCache *cache = MEM_callocN(sizeof(HairExportCache), "hair export cache");
+	return cache;
+}
+
+/* Returns flags for missing data parts */
+
+static int hair_export_cache_get_required_updates(const HairExportCache *cache)
+{
+	int data = 0;
+	if (!cache->fiber_curves)
+	{
+		data |= HAIR_EXPORT_FIBER_CURVES;
+	}
+	if (!cache->fiber_verts || !cache->fiber_normals || !cache->fiber_tangents)
+	{
+		data |= HAIR_EXPORT_FIBER_VERTICES;
+	}
+	if (!cache->follicles)
+	{
+		data |= HAIR_EXPORT_FOLLICLE_BINDING;
+	}
+	if (!cache->follicle_root_position)
+	{
+		data |= HAIR_EXPORT_FOLLICLE_ROOT_POSITIONS;
+	}
+	return data;
+}
+
+/* Include data dependencies of the given flags */
+
+static int hair_export_cache_get_dependencies(int data)
+{
+	/* Ordering here is important to account for recursive dependencies */
+	
+	if (data & HAIR_EXPORT_FIBER_CURVES)
+		data |= HAIR_EXPORT_FIBER_VERTICES | HAIR_EXPORT_FOLLICLE_BINDING;
+	
+	if (data & HAIR_EXPORT_FOLLICLE_BINDING)
+		data |= HAIR_EXPORT_FOLLICLE_ROOT_POSITIONS;
+	
+	return data;
+}
+
+/* Update an existing export cache to ensure it contains the requested data.
+ * Returns flags for data that has been updated.
+ */
+
+int BKE_hair_export_cache_update(HairExportCache *cache, const HairSystem *hsys,
+                                 int subdiv, Mesh *scalp, int requested_data)
+{
+	/* Include dependencies */
+	int data = hair_export_cache_get_dependencies(requested_data);
+	
+	int uncached = hair_export_cache_get_required_updates(cache);
+	/* Invalid data should already include all dependencies */
+	BLI_assert(uncached == hair_export_cache_get_dependencies(uncached));
+	
+	/* Only update invalidated parts */
+	data &= uncached;
+	
+	if (data & HAIR_EXPORT_FIBER_CURVES)
+	{
+		/* Cache subdivided curves */
+		const int totcurves = cache->totcurves = hsys->curve_data.totcurves;
+		cache->fiber_curves = MEM_reallocN_id(cache->fiber_curves, sizeof(HairFiberCurve) * totcurves, "hair export curves");
+		
+		int totverts = 0;
+		for (int i = 0; i < totcurves; ++i) {
+			const HairFiberCurve *curve_orig = &hsys->curve_data.curves[i];
+			HairFiberCurve *curve = &cache->fiber_curves[i];
+			
+			memcpy(curve, curve_orig, sizeof(HairFiberCurve));
+			curve->numverts = hair_get_strand_subdiv_length(curve_orig->numverts, subdiv);
+			curve->vertstart = totverts;
+			
+			totverts  += curve->numverts;
+		}
+		cache->totverts = totverts;
+	}
+	
+	if (data & HAIR_EXPORT_FIBER_VERTICES)
+	{
+		const int totcurves = cache->totcurves;
+		const int totverts = cache->totverts;
+		cache->fiber_verts = MEM_reallocN_id(cache->fiber_verts, sizeof(HairFiberVertex) * totverts, "hair export verts");
+		cache->fiber_tangents = MEM_reallocN_id(cache->fiber_tangents, sizeof(float[3]) * totverts, "hair export tangents");
+		cache->fiber_normals = MEM_reallocN_id(cache->fiber_normals, sizeof(float[3]) * totverts, "hair export normals");
+		
+		for (int i = 0; i < totcurves; ++i) {
+			const HairFiberCurve *curve_orig = &hsys->curve_data.curves[i];
+			const HairFiberVertex *verts_orig = &hsys->curve_data.verts[curve_orig->vertstart];
+			const HairFiberCurve *curve = &cache->fiber_curves[i];
+			HairFiberVertex *verts = &cache->fiber_verts[curve->vertstart];
+			float (*tangents)[3] = &cache->fiber_tangents[curve->vertstart];
+			float (*normals)[3] = &cache->fiber_normals[curve->vertstart];
+			
+			hair_curve_subdivide(curve_orig, verts_orig, subdiv, verts);
+			
+			hair_curve_calc_vectors(verts, curve->numverts, tangents, normals);
+		}
+	}
+
+	if (hsys->pattern)
+	{
+		if (data & HAIR_EXPORT_FOLLICLE_BINDING)
+		{
+			cache->follicles = hsys->pattern->follicles;
+			cache->totfollicles = hsys->pattern->num_follicles;
+		}
+
+		if (data & HAIR_EXPORT_FOLLICLE_ROOT_POSITIONS)
+		{
+			const int totfibercurves = cache->totfollicles;
+			
+			cache->follicle_root_position = MEM_reallocN_id(cache->follicle_root_position, sizeof(float[3]) * totfibercurves, "fiber root position");
+			const HairFollicle *follicle = hsys->pattern->follicles;
+			for (int i = 0; i < totfibercurves; ++i, ++follicle) {
+				/* Cache fiber root position */
+				float nor[3], tang[3];
+				BKE_mesh_sample_eval(scalp, &follicle->mesh_sample, cache->follicle_root_position[i], nor, tang);
+			}
+		}
+	}
+	else
+	{
+		cache->follicles = NULL;
+		cache->totfollicles = 0;
+		
+		if (cache->follicle_root_position)
+		{
+			MEM_freeN(cache->follicle_root_position);
+			cache->follicle_root_position = NULL;
+		}
+	}
+	
+	return data;
+}
+
+/* Free the given export cache */
+
+void BKE_hair_export_cache_free(HairExportCache *cache)
+{
+	if (cache->fiber_curves)
+	{
+		MEM_freeN(cache->fiber_curves);
+	}
+	if (cache->fiber_verts)
+	{
+		MEM_freeN(cache->fiber_verts);
+	}
+	if (cache->fiber_tangents)
+	{
+		MEM_freeN(cache->fiber_tangents);
+	}
+	if (cache->fiber_normals)
+	{
+		MEM_freeN(cache->fiber_normals);
+	}
+	if (cache->follicle_root_position)
+	{
+		MEM_freeN(cache->follicle_root_position);
+	}
+	MEM_freeN(cache);
+}
+
+/* Invalidate all data in a hair export cache */
+
+void BKE_hair_export_cache_clear(HairExportCache *cache)
+{
+	/* Invalidate everything */
+	BKE_hair_export_cache_invalidate(cache, HAIR_EXPORT_ALL);
+}
+
+/* Invalidate part of the data in a hair export cache.
+ *
+ * Note some parts may get invalidated automatically based on internal dependencies.
+ */
+
+void BKE_hair_export_cache_invalidate(HairExportCache *cache, int invalidate)
+{
+	/* Include dependencies */
+	int data = hair_export_cache_get_dependencies(invalidate);
+
+	if (data & HAIR_EXPORT_FIBER_CURVES)
+	{
+		if (cache->fiber_curves)
+		{
+			MEM_freeN(cache->fiber_curves);
+			cache->fiber_curves = 0;
+		}
+	}
+	if (data & HAIR_EXPORT_FIBER_VERTICES)
+	{
+		if (cache->fiber_verts)
+		{
+			MEM_freeN(cache->fiber_verts);
+			cache->fiber_verts = NULL;
+		}
+		if (cache->fiber_tangents)
+		{
+			MEM_freeN(cache->fiber_tangents);
+			cache->fiber_tangents = NULL;
+		}
+		if (cache->fiber_normals)
+		{
+			MEM_freeN(cache->fiber_normals);
+			cache->fiber_tangents = NULL;
+		}
+	}
+	if (data & HAIR_EXPORT_FOLLICLE_BINDING)
+	{
+		cache->follicles = NULL;
+	}
+	if (data & HAIR_EXPORT_FOLLICLE_ROOT_POSITIONS)
+	{
+		if (cache->follicle_root_position)
+		{
+			MEM_freeN(cache->follicle_root_position);
+			cache->follicle_root_position = NULL;
+		}
+	}
+}

source/blender/blenkernel/intern/hair_draw.c

@@ -0,0 +1,314 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) Blender Foundation
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): Lukas Toenne
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/blenkernel/intern/hair_draw.c
+ *  \ingroup bke
+ */
+
+#include <string.h>
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_math.h"
+#include "BLI_kdtree.h"
+#include "BLI_rand.h"
+
+#include "DNA_hair_types.h"
+
+#include "BKE_mesh_sample.h"
+#include "BKE_hair.h"
+
+/* === Draw Settings === */
+
+HairDrawSettings* BKE_hair_draw_settings_new(void)
+{
+	HairDrawSettings *draw_settings = MEM_callocN(sizeof(HairDrawSettings), "hair draw settings");
+	
+	draw_settings->follicle_mode = HAIR_DRAW_FOLLICLE_POINTS;
+	draw_settings->fiber_mode = HAIR_DRAW_FIBER_CURVES;
+	draw_settings->shape_flag = HAIR_DRAW_CLOSE_TIP;
+	draw_settings->shape = 0.0f;
+	draw_settings->root_radius = 1.0f;
+	draw_settings->tip_radius = 0.0f;
+	draw_settings->radius_scale = 0.01f;
+	
+	return draw_settings;
+}
+
+HairDrawSettings* BKE_hair_draw_settings_copy(HairDrawSettings *draw_settings)
+{
+	HairDrawSettings *ndraw_settings = MEM_dupallocN(draw_settings);
+	return ndraw_settings;
+}
+
+void BKE_hair_draw_settings_free(HairDrawSettings *draw_settings)
+{
+	MEM_freeN(draw_settings);
+}
+
+/* === Draw Cache === */
+
+typedef struct HairFiberTextureBuffer {
+	unsigned int parent_index[4];
+	float parent_weight[4];
+	float root_position[3];
+	int pad;
+} HairFiberTextureBuffer;
+BLI_STATIC_ASSERT_ALIGN(HairFiberTextureBuffer, 8)
+
+typedef struct HairStrandVertexTextureBuffer {
+	float co[3];
+	float nor[3];
+	float tang[3];
+	float len;
+} HairStrandVertexTextureBuffer;
+BLI_STATIC_ASSERT_ALIGN(HairStrandVertexTextureBuffer, 8)
+
+typedef struct HairStrandMapTextureBuffer {
+	unsigned int vertex_start;
+	unsigned int vertex_count;
+	
+	/* Shape attributes */
+	float taper_length;         /* Distance at which final thickness is reached */
+	float taper_thickness;      /* Relative thickness of the strand */
+} HairStrandMapTextureBuffer;
+BLI_STATIC_ASSERT_ALIGN(HairStrandMapTextureBuffer, 8)
+
+static void hair_get_strand_buffer(
+        const HairExportCache *cache,
+        HairStrandMapTextureBuffer *strand_map_buffer,
+        HairStrandVertexTextureBuffer *strand_vertex_buffer)
+{
+	for (int i = 0; i < cache->totcurves; ++i) {
+		const HairFiberCurve *curve = &cache->fiber_curves[i];
+		const HairFiberVertex *verts = &cache->fiber_verts[curve->vertstart];
+		const float (*tangents)[3] = &cache->fiber_tangents[curve->vertstart];
+		const float (*normals)[3] = &cache->fiber_normals[curve->vertstart];
+		HairStrandMapTextureBuffer *smap = &strand_map_buffer[i];
+		HairStrandVertexTextureBuffer *svert = &strand_vertex_buffer[curve->vertstart];
+		
+		smap->vertex_start = curve->vertstart;
+		smap->vertex_count = curve->numverts;
+		smap->taper_length = curve->taper_length;
+		smap->taper_thickness = curve->taper_thickness;
+		
+		float len = 0.0f;
+		for (int j = 0; j < curve->numverts; ++j)
+		{
+			copy_v3_v3(svert[j].co, verts[j].co);
+			copy_v3_v3(svert[j].tang, tangents[j]);
+			copy_v3_v3(svert[j].nor, normals[j]);
+			
+			if (j > 0)
+			{
+				len += len_v3v3(verts[j-1].co, verts[j].co);
+			}
+			svert[j].len = len;
+		}
+	}
+}
+
+static void hair_get_fiber_buffer(const HairExportCache *cache,
+                                  HairFiberTextureBuffer *fiber_buf)
+{
+	const int totfibers = cache->totfollicles;
+	const HairFollicle *follicle = cache->follicles;
+	HairFiberTextureBuffer *fb = fiber_buf;
+	for (int i = 0; i < totfibers; ++i, ++fb, ++follicle) {
+		copy_v3_v3(fb->root_position, cache->follicle_root_position[i]);
+		
+		fb->parent_index[0] = follicle->curve;
+		fb->parent_index[1] = HAIR_CURVE_INDEX_NONE;
+		fb->parent_index[2] = HAIR_CURVE_INDEX_NONE;
+		fb->parent_index[3] = HAIR_CURVE_INDEX_NONE;
+		fb->parent_weight[0] = 1.0f;
+		fb->parent_weight[1] = 0.0f;
+		fb->parent_weight[2] = 0.0f;
+		fb->parent_weight[3] = 0.0f;
+	}
+}
+
+void BKE_hair_get_texture_buffer_size(
+        const HairExportCache *cache,
+        int *r_size,
+        int *r_strand_map_start,
+        int *r_strand_vertex_start,
+        int *r_fiber_start)
+{
+	*r_strand_map_start = 0;
+	*r_strand_vertex_start = *r_strand_map_start + cache->totcurves * sizeof(HairStrandMapTextureBuffer);
+	*r_fiber_start = *r_strand_vertex_start + cache->totverts * sizeof(HairStrandVertexTextureBuffer);
+	*r_size = *r_fiber_start + cache->totfollicles * sizeof(HairFiberTextureBuffer);
+}
+
+void BKE_hair_get_texture_buffer(
+        const HairExportCache *cache,
+        void *buffer)
+{
+	int size, strand_map_start, strand_vertex_start, fiber_start;
+	BKE_hair_get_texture_buffer_size(cache, &size, &strand_map_start, &strand_vertex_start, &fiber_start);
+	
+	HairStrandMapTextureBuffer *strand_map = (HairStrandMapTextureBuffer*)((char*)buffer + strand_map_start);
+	HairStrandVertexTextureBuffer *strand_verts = (HairStrandVertexTextureBuffer*)((char*)buffer + strand_vertex_start);
+	HairFiberTextureBuffer *fibers = (HairFiberTextureBuffer*)((char*)buffer + fiber_start);
+	
+	hair_get_strand_buffer(
+	            cache,
+	            strand_map,
+	            strand_verts);
+	hair_get_fiber_buffer(
+	            cache,
+	            fibers);
+}
+
+void (*BKE_hair_batch_cache_dirty_cb)(HairSystem* hsys, int mode) = NULL;
+void (*BKE_hair_batch_cache_free_cb)(HairSystem* hsys) = NULL;
+
+void BKE_hair_batch_cache_dirty(HairSystem* hsys, int mode)
+{
+	if (hsys->draw_batch_cache) {
+		BKE_hair_batch_cache_dirty_cb(hsys, mode);
+	}
+}
+
+void BKE_hair_batch_cache_free(HairSystem* hsys)
+{
+	if (hsys->draw_batch_cache || hsys->draw_texture_cache) {
+		BKE_hair_batch_cache_free_cb(hsys);
+	}
+}
+
+/* === Fiber Curve Interpolation === */
+
+/* NOTE: Keep this code in sync with the GLSL version!
+ * see common_hair_fibers_lib.glsl
+ */
+
+/* Subdivide a curve */
+static int hair_curve_subdivide(
+        const HairFiberCurve* curve,
+        const HairFiberVertex* verts,
+        int subdiv,
+        int vertco_stride,
+        float *r_vertco)
+{
+	{
+		/* Move vertex positions from the dense array to their initial configuration for subdivision.
+		 * Also add offset to ensure the curve starts on the scalp surface.
+		 */
+		const int step = (1 << subdiv) * vertco_stride;
+		BLI_assert(curve->numverts > 0);
+		
+		float *dst = r_vertco;
+		for (int i = 0; i < curve->numverts; ++i) {
+			copy_v3_v3(dst, verts[i].co);
+			dst = POINTER_OFFSET(dst, step);
+		}
+	}
+	
+	/* Subdivide */
+	for (int d = 0; d < subdiv; ++d) {
+		const int num_edges = (curve->numverts - 1) << d;
+		const int hstep = (1 << (subdiv - d - 1)) * vertco_stride;
+		const int step = (1 << (subdiv - d)) * vertco_stride;
+		
+		/* Calculate edge points */
+		{
+			float *p = r_vertco;
+			for (int k = 0; k < num_edges; ++k) {
+				float *ps = POINTER_OFFSET(p, step);
+				float *ph = POINTER_OFFSET(p, hstep);
+				add_v3_v3v3(ph, p, ps);
+				mul_v3_fl(ph, 0.5f);
+				p = ps;
+			}
+		}
+		
+		/* Move original points */
+		{
+			float *p = r_vertco;
+			for (int k = 1; k < num_edges; ++k) {
+				float *ps = POINTER_OFFSET(p, step);
+				float *ph = POINTER_OFFSET(p, hstep);
+				float *hp = POINTER_OFFSET(p, -hstep);
+				add_v3_v3v3(p, hp, ph);
+				mul_v3_fl(p, 0.5f);
+				p = ps;
+			}
+		}
+	}
+	
+	const int num_verts = ((curve->numverts - 1) << subdiv) + 1;
+	return num_verts;
+}
+
+/* === Render API === */
+
+/* Calculate required size for render buffers. */
+void BKE_hair_render_get_buffer_size(
+        const HairExportCache* cache,
+        int subdiv,
+        int *r_totcurves,
+        int *r_totverts)
+{
+	*r_totcurves = cache->totfollicles;
+	
+	const int subdiv_factor = 1 << subdiv;
+	for (int i = 0; i < cache->totfollicles; ++i)
+	{
+		const int numverts = cache->fiber_curves[cache->follicles[i].curve].numverts;
+		*r_totverts = (numverts - 1) * subdiv_factor + 1;
+	}
+}
+
+/* Create render data in existing buffers.
+ * Buffers must be large enough according to BKE_hair_get_render_buffer_size.
+ */
+void BKE_hair_render_fill_buffers(
+        const HairExportCache* cache,
+        int subdiv,
+        int vertco_stride,
+        int *r_curvestart,
+        int *r_curvelen,
+        float *r_vertco)
+{
+	int vertstart = 0;
+	float *vert = r_vertco;
+	for (int i = 0; i < cache->totfollicles; ++i)
+	{
+		const HairFiberCurve *curve = &cache->fiber_curves[cache->follicles[i].curve];
+		const HairFiberVertex *verts = &cache->fiber_verts[curve->vertstart];
+		const int numverts = curve->numverts;
+		r_curvestart[i] = vertstart;
+		r_curvelen[i] = numverts;
+		
+		hair_curve_subdivide(curve, verts, subdiv, vertco_stride, vert);
+		
+		vertstart += numverts;
+		vert = POINTER_OFFSET(vert, vertco_stride * numverts);
+	}
+}

source/blender/blenkernel/intern/library.c

@@ -47,8 +47,8 @@
 #include "DNA_brush_types.h"
 #include "DNA_cachefile_types.h"
 #include "DNA_camera_types.h"
-#include "DNA_group_types.h"
 #include "DNA_gpencil_types.h"
+#include "DNA_group_types.h"
 #include "DNA_ipo_types.h"
 #include "DNA_key_types.h"
 #include "DNA_lamp_types.h"
@@ -1057,6 +1057,8 @@ void BKE_main_lib_objects_recalc_all(Main *bmain)
 	DEG_id_type_tag(bmain, ID_OB);
 }
 
+BLI_STATIC_ASSERT(MAX_LIBARRAY == INDEX_ID_NULL + 1, "MAX_LIBARRAY must be large enough for all ID types")
+
 /**
  * puts into array *lb pointers to all the ListBase structs in main,
  * and returns the number of them as the function result. This is useful for

source/blender/blenkernel/intern/particle.c

@@ -1437,7 +1437,7 @@ int psys_particle_dm_face_lookup(
 	return DMCACHE_NOTFOUND;
 }
 
-static int psys_map_index_on_dm(Mesh *mesh, int from, int index, int index_dmcache, const float fw[4], float UNUSED(foffset), int *mapindex, float mapfw[4])
+static int psys_map_index_on_mesh(Mesh *mesh, int from, int index, int index_dmcache, const float fw[4], float UNUSED(foffset), int *mapindex, float mapfw[4])
 {
 	if (index < 0)
 		return 0;
@@ -1497,6 +1497,11 @@ static int psys_map_index_on_dm(Mesh *mesh, int from, int index, int index_dmcac
 	return 1;
 }
 
+int psys_get_index_on_mesh(ParticleSystem *psys, Mesh *mesh, ParticleData *pa, int *mapindex, float mapfw[4])
+{
+	return psys_map_index_on_mesh(mesh, psys->part->from, pa->num, pa->num_dmcache, pa->fuv, pa->foffset, mapindex, mapfw);
+}
+
 /* interprets particle data to get a point on a mesh in object space */
 void psys_particle_on_dm(Mesh *mesh_final, int from, int index, int index_dmcache,
                          const float fw[4], float foffset, float vec[3], float nor[3], float utan[3], float vtan[3],
@@ -1506,7 +1511,7 @@ void psys_particle_on_dm(Mesh *mesh_final, int from, int index, int index_dmcach
 	float (*orcodata)[3];
 	int mapindex;
 
-	if (!psys_map_index_on_dm(mesh_final, from, index, index_dmcache, fw, foffset, &mapindex, mapfw)) {
+	if (!psys_map_index_on_mesh(mesh_final, from, index, index_dmcache, fw, foffset, &mapindex, mapfw)) {
 		if (vec) { vec[0] = vec[1] = vec[2] = 0.0; }
 		if (nor) { nor[0] = nor[1] = 0.0; nor[2] = 1.0; }
 		if (orco) { orco[0] = orco[1] = orco[2] = 0.0; }
@@ -1571,7 +1576,7 @@ float psys_particle_value_from_verts(Mesh *mesh, short from, ParticleData *pa, f
 	float mapfw[4];
 	int mapindex;
 
-	if (!psys_map_index_on_dm(mesh, from, pa->num, pa->num_dmcache, pa->fuv, pa->foffset, &mapindex, mapfw))
+	if (!psys_map_index_on_mesh(mesh, from, pa->num, pa->num_dmcache, pa->fuv, pa->foffset, &mapindex, mapfw))
 		return 0.0f;
 
 	return psys_interpolate_value_from_verts(mesh, from, mapindex, mapfw, values);

source/blender/blenlib/BLI_math_geom.h

@@ -376,6 +376,8 @@ bool clip_segment_v3_plane_n(
 /****************************** Interpolation ********************************/
 void interp_weights_tri_v3(float w[3], const float a[3], const float b[3], const float c[3], const float p[3]);
 void interp_weights_quad_v3(float w[4], const float a[3], const float b[3], const float c[3], const float d[3], const float p[3]);
+/* also returns three indices of the triangle actually used */
+void interp_weights_quad_v3_index(int tri[3], float w[4], const float v1[3], const float v2[3], const float v3[3], const float v4[3], const float co[3]);
 void interp_weights_poly_v3(float w[], float v[][3], const int n, const float co[3]);
 void interp_weights_poly_v2(float w[], float v[][2], const int n, const float co[2]);
 

source/blender/blenlib/intern/math_geom.c

@@ -3272,6 +3272,71 @@ void interp_weights_quad_v3(float w[4], const float v1[3], const float v2[3], co
 	}
 }
 
+void interp_weights_quad_v3_index(int tri[3], float w[4], const float v1[3], const float v2[3], const float v3[3], const float v4[3], const float co[3])
+{
+	float w2[3];
+
+	w[0] = w[1] = w[2] = w[3] = 0.0f;
+	tri[0] = tri[1] = tri[2] = -1;
+
+	/* first check for exact match */
+	if (equals_v3v3(co, v1)) {
+		w[0] = 1.0f;
+		tri[0] = 0; tri[1] = 1; tri[2] = 3;
+	}
+	else if (equals_v3v3(co, v2)) {
+		w[1] = 1.0f;
+		tri[0] = 0; tri[1] = 1; tri[2] = 3;
+	}
+	else if (equals_v3v3(co, v3)) {
+		w[2] = 1.0f;
+		tri[0] = 1; tri[1] = 2; tri[2] = 3;
+	}
+	else if (v4 && equals_v3v3(co, v4)) {
+		w[3] = 1.0f;
+		tri[0] = 1; tri[1] = 2; tri[2] = 3;
+	}
+	else {
+		/* otherwise compute barycentric interpolation weights */
+		float n1[3], n2[3], n[3];
+		bool degenerate;
+
+		sub_v3_v3v3(n1, v1, v3);
+		if (v4) {
+			sub_v3_v3v3(n2, v2, v4);
+		}
+		else {
+			sub_v3_v3v3(n2, v2, v3);
+		}
+		cross_v3_v3v3(n, n1, n2);
+
+		/* OpenGL seems to split this way, so we do too */
+		if (v4) {
+			degenerate = barycentric_weights(v1, v2, v4, co, n, w);
+			SWAP(float, w[2], w[3]);
+			tri[0] = 0; tri[1] = 1; tri[2] = 3;
+
+			if (degenerate || (w[0] < 0.0f)) {
+				/* if w[1] is negative, co is on the other side of the v1-v3 edge,
+				 * so we interpolate using the other triangle */
+				degenerate = barycentric_weights(v2, v3, v4, co, n, w2);
+
+				if (!degenerate) {
+					w[0] = 0.0f;
+					w[1] = w2[0];
+					w[2] = w2[1];
+					w[3] = w2[2];
+					tri[0] = 1; tri[1] = 2; tri[2] = 3;
+				}
+			}
+		}
+		else {
+			barycentric_weights(v1, v2, v3, co, n, w);
+			tri[0] = 0; tri[1] = 1; tri[2] = 2;
+		}
+	}
+}
+
 /* return 1 of point is inside triangle, 2 if it's on the edge, 0 if point is outside of triangle */
 int barycentric_inside_triangle_v2(const float w[3])
 {

source/blender/blenloader/intern/readfile.c

@@ -73,6 +73,7 @@
 #include "DNA_group_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_gpencil_modifier_types.h"
+#include "DNA_hair_types.h"
 #include "DNA_shader_fx_types.h"
 #include "DNA_ipo_types.h"
 #include "DNA_key_types.h"
@@ -5095,6 +5096,25 @@ static void direct_link_pose(FileData *fd, bPose *pose)
 	}
 }
 
+static void direct_link_hair(FileData *fd, HairSystem* hsys)
+{
+	if (!hsys) {
+		return;
+	}
+	
+	hsys->pattern = newdataadr(fd, hsys->pattern);
+	if ( hsys->pattern )
+	{
+		hsys->pattern->follicles = newdataadr(fd, hsys->pattern->follicles);
+	}
+	
+	hsys->curve_data.curves = newdataadr(fd, hsys->curve_data.curves);
+	hsys->curve_data.verts = newdataadr(fd, hsys->curve_data.verts);
+	
+	hsys->draw_batch_cache = NULL;
+	hsys->draw_texture_cache = NULL;
+}
+
 static void direct_link_modifiers(FileData *fd, ListBase *lb)
 {
 	ModifierData *md;
@@ -5418,6 +5438,16 @@ static void direct_link_modifiers(FileData *fd, ListBase *lb)
 				}
 			}
 		}
+		else if (md->type == eModifierType_Hair) {
+			HairModifierData *hmd = (HairModifierData *)md;
+			
+			hmd->hair_system = newdataadr(fd, hmd->hair_system);
+			direct_link_hair(fd, hmd->hair_system);
+			
+			hmd->draw_settings = newdataadr(fd, hmd->draw_settings);
+
+			BLI_listbase_clear(&hmd->fiber_curves); // runtime
+		}
 	}
 }
 

source/blender/blenloader/intern/writefile.c

@@ -121,6 +121,7 @@
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_shader_fx_types.h"
 #include "DNA_fileglobal_types.h"
+#include "DNA_hair_types.h"
 #include "DNA_key_types.h"
 #include "DNA_lattice_types.h"
 #include "DNA_lamp_types.h"
@@ -1617,6 +1618,18 @@ static void write_fmaps(WriteData *wd, ListBase *fbase)
 	}
 }
 
+static void write_hair(WriteData *wd, HairSystem *hsys)
+{
+	if ( hsys->pattern )
+	{
+		writestruct(wd, DATA, HairPattern, 1, hsys->pattern);
+		writestruct(wd, DATA, HairFollicle, hsys->pattern->num_follicles, hsys->pattern->follicles);
+	}
+	
+	writestruct(wd, DATA, HairFiberCurve, hsys->curve_data.totcurves, hsys->curve_data.curves);
+	writestruct(wd, DATA, HairFiberVertex, hsys->curve_data.totverts, hsys->curve_data.verts);
+}
+
 static void write_modifiers(WriteData *wd, ListBase *modbase)
 {
 	ModifierData *md;
@@ -1788,6 +1801,18 @@ static void write_modifiers(WriteData *wd, ListBase *modbase)
 				}
 			}
 		}
+		else if (md->type == eModifierType_Hair) {
+			HairModifierData *hmd = (HairModifierData *)md;
+			
+			if (hmd->hair_system) {
+				writestruct(wd, DATA, HairSystem, 1, hmd->hair_system);
+				write_hair(wd, hmd->hair_system);
+			}
+			if (hmd->draw_settings)
+			{
+				writestruct(wd, DATA, HairDrawSettings, 1, hmd->draw_settings);
+			}
+		}
 	}
 }
 

source/blender/draw/CMakeLists.txt

@@ -58,6 +58,7 @@ set(SRC
 	intern/draw_cache.c
 	intern/draw_cache_impl_curve.c
 	intern/draw_cache_impl_displist.c
+	intern/draw_cache_impl_hair.c
 	intern/draw_cache_impl_lattice.c
 	intern/draw_cache_impl_mesh.c
 	intern/draw_cache_impl_metaball.c

source/blender/draw/engines/eevee/eevee_materials.c

@@ -31,6 +31,7 @@
 #include "BLI_rand.h"
 #include "BLI_string_utils.h"
 
+#include "BKE_hair.h"
 #include "BKE_particle.h"
 #include "BKE_paint.h"
 #include "BKE_pbvh.h"
@@ -39,6 +40,7 @@
 #include "DNA_world_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_view3d_types.h"
+#include "DNA_hair_types.h"
 
 #include "GPU_material.h"
 
@@ -812,6 +814,7 @@ struct GPUMaterial *EEVEE_material_hair_get(
 	options |= eevee_material_shadow_option(shadow_method);
 
 	GPUMaterial *mat = DRW_shader_find_from_material(ma, engine, options, true);
+
 	if (mat) {
 		return mat;
 	}
@@ -862,14 +865,16 @@ static struct DRWShadingGroup *EEVEE_default_shading_group_create(
  **/
 static struct DRWShadingGroup *EEVEE_default_shading_group_get(
         EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata,
-        Object *ob, ParticleSystem *psys, ModifierData *md,
+        Object *ob,
+        ParticleSystem *psys, ModifierData *md,
+        HairSystem *hsys, const HairDrawSettings *hdraw, struct Mesh *scalp,
         bool is_hair, bool is_flat_normal, bool use_ssr, int shadow_method)
 {
 	static int ssr_id;
 	ssr_id = (use_ssr) ? 1 : -1;
 	int options = VAR_MAT_MESH;
 
-	BLI_assert(!is_hair || (ob && psys && md));
+	BLI_assert(!is_hair || (ob && psys && md) || (ob && hsys && hdraw && scalp));
 
 	if (is_hair) options |= VAR_MAT_HAIR;
 	if (is_flat_normal) options |= VAR_MAT_FLAT;
@@ -894,10 +899,19 @@ static struct DRWShadingGroup *EEVEE_default_shading_group_get(
 	}
 
 	if (is_hair) {
-		DRWShadingGroup *shgrp = DRW_shgroup_hair_create(ob, psys, md,
-		                                                 vedata->psl->default_pass[options],
-		                                                 e_data.default_lit[options]);
+		DRWShadingGroup *shgrp = NULL;
+		if (psys && md) {
+			shgrp = DRW_shgroup_particle_hair_create(ob, psys, md,
+			                                         vedata->psl->default_pass[options],
+			                                         e_data.default_lit[options]);
+		}
+		else if (hsys && hdraw && scalp) {
+			shgrp = DRW_shgroup_hair_create(ob, hsys, scalp, hdraw,
+			                                vedata->psl->default_pass[options],
+			                                e_data.default_lit[options]);
+		}
 		add_standard_uniforms(shgrp, sldata, vedata, &ssr_id, NULL, true, true, false, false, false);
+
 		return shgrp;
 	}
 	else {
@@ -1266,7 +1280,7 @@ static void material_opaque(
 	if (*shgrp == NULL) {
 		bool use_ssr = ((effects->enabled_effects & EFFECT_SSR) != 0);
 		*shgrp = EEVEE_default_shading_group_get(sldata, vedata,
-		                                         NULL, NULL, NULL,
+		                                         NULL, NULL, NULL, NULL, NULL, NULL,
 		                                         false, use_flat_nor, use_ssr, linfo->shadow_method);
 		DRW_shgroup_uniform_vec3(*shgrp, "basecol", color_p, 1);
 		DRW_shgroup_uniform_float(*shgrp, "metallic", metal_p, 1);
@@ -1409,6 +1423,217 @@ static void material_transparent(
 	}
 }
 
+static void material_particle_hair(
+        EEVEE_Data *vedata,
+        EEVEE_ViewLayerData *sldata,
+        Object *ob,
+        ParticleSystem *psys,
+        ModifierData *md)
+{
+	EEVEE_PassList *psl = ((EEVEE_Data *)vedata)->psl;
+	EEVEE_StorageList *stl = ((EEVEE_Data *)vedata)->stl;
+	const DRWContextState *draw_ctx = DRW_context_state_get();
+	Scene *scene = draw_ctx->scene;
+	bool use_ssr = ((stl->effects->enabled_effects & EFFECT_SSR) != 0);
+
+	if (!psys_check_enabled(ob, psys, false)) {
+		return;
+	}
+	if (!DRW_check_psys_visible_within_active_context(ob, psys)) {
+		return;
+	}
+	ParticleSettings *part = psys->part;
+	const int draw_as = (part->draw_as == PART_DRAW_REND) ? part->ren_as : part->draw_as;
+	if (draw_as != PART_DRAW_PATH) {
+		return;
+	}
+
+	DRWShadingGroup *shgrp = NULL;
+	Material *ma = give_current_material(ob, part->omat);
+
+	if (ma == NULL) {
+		ma = &defmaterial;
+	}
+
+	float *color_p = &ma->r;
+	float *metal_p = &ma->metallic;
+	float *spec_p = &ma->spec;
+	float *rough_p = &ma->roughness;
+
+	shgrp = DRW_shgroup_particle_hair_create(
+	        ob, psys, md,
+	        psl->depth_pass,
+	        e_data.default_hair_prepass_sh);
+
+	shgrp = DRW_shgroup_particle_hair_create(
+	        ob, psys, md,
+	        psl->depth_pass_clip,
+	        e_data.default_hair_prepass_clip_sh);
+	DRW_shgroup_uniform_block(shgrp, "clip_block", sldata->clip_ubo);
+
+	shgrp = NULL;
+	if (ma->use_nodes && ma->nodetree) {
+		static int ssr_id;
+		ssr_id = (use_ssr) ? 1 : -1;
+		static float half = 0.5f;
+		static float error_col[3] = {1.0f, 0.0f, 1.0f};
+		static float compile_col[3] = {0.5f, 0.5f, 0.5f};
+		struct GPUMaterial *gpumat = EEVEE_material_hair_get(scene, ma, sldata->lamps->shadow_method);
+
+		switch (GPU_material_status(gpumat)) {
+			case GPU_MAT_SUCCESS:
+			{
+				bool use_diffuse = GPU_material_flag_get(gpumat, GPU_MATFLAG_DIFFUSE);
+				bool use_glossy = GPU_material_flag_get(gpumat, GPU_MATFLAG_GLOSSY);
+				bool use_refract = GPU_material_flag_get(gpumat, GPU_MATFLAG_REFRACT);
+
+				shgrp = DRW_shgroup_material_particle_hair_create(
+				        ob, psys, md,
+				        psl->material_pass,
+				        gpumat);
+
+				add_standard_uniforms(shgrp, sldata, vedata, &ssr_id, NULL,
+				                      use_diffuse, use_glossy, use_refract, false, false);
+				break;
+			}
+			case GPU_MAT_QUEUED:
+			{
+				color_p = compile_col;
+				metal_p = spec_p = rough_p = ½
+				break;
+			}
+			case GPU_MAT_FAILED:
+			default:
+				color_p = error_col;
+				metal_p = spec_p = rough_p = ½
+				break;
+		}
+	}
+
+	/* Fallback to default shader */
+	if (shgrp == NULL) {
+		shgrp = EEVEE_default_shading_group_get(sldata, vedata,
+		                                        ob, psys, md, NULL, NULL, NULL,
+		                                        true, false, use_ssr,
+		                                        sldata->lamps->shadow_method);
+		DRW_shgroup_uniform_vec3(shgrp, "basecol", color_p, 1);
+		DRW_shgroup_uniform_float(shgrp, "metallic", metal_p, 1);
+		DRW_shgroup_uniform_float(shgrp, "specular", spec_p, 1);
+		DRW_shgroup_uniform_float(shgrp, "roughness", rough_p, 1);
+	}
+	
+	/* Shadows */
+	DRW_shgroup_particle_hair_create(
+	        ob, psys, md,
+	        psl->shadow_pass,
+	        e_data.default_hair_prepass_sh);
+}
+
+static void material_hair(
+        EEVEE_Data *vedata,
+        EEVEE_ViewLayerData *sldata,
+        Object *ob,
+        HairSystem *hsys,
+        const HairDrawSettings *draw_set,
+        Material *ma,
+        struct Mesh *scalp)
+{
+	EEVEE_PassList *psl = ((EEVEE_Data *)vedata)->psl;
+	EEVEE_StorageList *stl = ((EEVEE_Data *)vedata)->stl;
+	const bool use_ssr = ((stl->effects->enabled_effects & EFFECT_SSR) != 0);
+	const DRWContextState *draw_ctx = DRW_context_state_get();
+	Scene *scene = draw_ctx->scene;
+	float mat[4][4];
+	copy_m4_m4(mat, ob->obmat);
+	
+	if (draw_set->fiber_mode != HAIR_DRAW_FIBER_CURVES)
+	{
+		return;
+	}
+	
+	if (ma == NULL) {
+		ma = &defmaterial;
+	}
+	
+	{
+		/*DRWShadingGroup *shgrp =*/ DRW_shgroup_hair_create(
+		            ob, hsys, scalp, draw_set,
+		            psl->depth_pass,
+		            e_data.default_hair_prepass_sh);
+	}
+	{
+		DRWShadingGroup *shgrp = DRW_shgroup_hair_create(
+		                             ob, hsys, scalp, draw_set,
+		                             psl->depth_pass_clip,
+		                             e_data.default_hair_prepass_clip_sh);
+		DRW_shgroup_uniform_block(shgrp, "clip_block", sldata->clip_ubo);
+	}
+	
+	{
+		float *color_p = &ma->r;
+		float *metal_p = &ma->metallic;
+		float *spec_p = &ma->spec;
+		float *rough_p = &ma->roughness;
+		
+		DRWShadingGroup *shgrp = NULL;
+		if (ma->use_nodes && ma->nodetree) {
+			static int ssr_id;
+			ssr_id = (use_ssr) ? 1 : -1;
+			static float half = 0.5f;
+			static float error_col[3] = {1.0f, 0.0f, 1.0f};
+			static float compile_col[3] = {0.5f, 0.5f, 0.5f};
+			struct GPUMaterial *gpumat = EEVEE_material_hair_get(scene, ma, sldata->lamps->shadow_method);
+			
+			switch (GPU_material_status(gpumat)) {
+				case GPU_MAT_SUCCESS:
+				{
+					bool use_diffuse = GPU_material_flag_get(gpumat, GPU_MATFLAG_DIFFUSE);
+					bool use_glossy = GPU_material_flag_get(gpumat, GPU_MATFLAG_GLOSSY);
+					bool use_refract = GPU_material_flag_get(gpumat, GPU_MATFLAG_REFRACT);
+
+					shgrp = DRW_shgroup_material_hair_create(
+					            ob, hsys, scalp, draw_set,
+					            psl->material_pass,
+					            gpumat);
+
+					add_standard_uniforms(shgrp, sldata, vedata, &ssr_id, NULL,
+					                      use_diffuse, use_glossy, use_refract, false, false);
+					break;
+				}
+				case GPU_MAT_QUEUED:
+				{
+					color_p = compile_col;
+					metal_p = spec_p = rough_p = ½
+					break;
+				}
+				case GPU_MAT_FAILED:
+				default:
+					color_p = error_col;
+					metal_p = spec_p = rough_p = ½
+					break;
+			}
+		}
+		
+		/* Fallback to default shader */
+		if (shgrp == NULL) {
+			shgrp = EEVEE_default_shading_group_get(sldata, vedata,
+			                                        ob, NULL, NULL, hsys, draw_set, scalp,
+			                                        true, false, use_ssr,
+			                                        sldata->lamps->shadow_method);
+			DRW_shgroup_uniform_vec3(shgrp, "basecol", color_p, 1);
+			DRW_shgroup_uniform_float(shgrp, "metallic", metal_p, 1);
+			DRW_shgroup_uniform_float(shgrp, "specular", spec_p, 1);
+			DRW_shgroup_uniform_float(shgrp, "roughness", rough_p, 1);
+		}
+	}
+	
+	/* Shadows */
+	DRW_shgroup_hair_create(
+	            ob, hsys, scalp, draw_set,
+	            psl->shadow_pass,
+	            e_data.default_hair_prepass_sh);
+}
+
 void EEVEE_materials_cache_populate(EEVEE_Data *vedata, EEVEE_ViewLayerData *sldata, Object *ob, bool *cast_shadow)
 {
 	EEVEE_PassList *psl = vedata->psl;
@@ -1600,112 +1825,24 @@ void EEVEE_materials_cache_populate(EEVEE_Data *vedata, EEVEE_ViewLayerData *sld
 
 void EEVEE_hair_cache_populate(EEVEE_Data *vedata, EEVEE_ViewLayerData *sldata, Object *ob, bool *cast_shadow)
 {
-	EEVEE_PassList *psl = vedata->psl;
-	EEVEE_StorageList *stl = vedata->stl;
 	const DRWContextState *draw_ctx = DRW_context_state_get();
-	Scene *scene = draw_ctx->scene;
-
-	bool use_ssr = ((stl->effects->enabled_effects & EFFECT_SSR) != 0);
 
 	if (ob->type == OB_MESH) {
 		if (ob != draw_ctx->object_edit) {
 			for (ModifierData *md = ob->modifiers.first; md; md = md->next) {
-				if (md->type != eModifierType_ParticleSystem) {
-					continue;
+				if (md->type == eModifierType_ParticleSystem) {
+					ParticleSystem *psys = ((ParticleSystemModifierData *)md)->psys;
+					material_particle_hair(vedata, sldata, ob, psys, md);
+					*cast_shadow = true;
 				}
-				ParticleSystem *psys = ((ParticleSystemModifierData *)md)->psys;
-				if (!psys_check_enabled(ob, psys, false)) {
-					continue;
+				else if (md->type == eModifierType_Hair) {
+					HairModifierData *hmd = (HairModifierData *)md;
+					
+					const int material_index = 1; /* TODO */
+					Material *material = give_current_material(ob, material_index);
+					
+					material_hair(vedata, sldata, ob, hmd->hair_system, hmd->draw_settings, material, ob->data);
 				}
-				if (!DRW_check_psys_visible_within_active_context(ob, psys)) {
-					continue;
-				}
-				ParticleSettings *part = psys->part;
-				const int draw_as = (part->draw_as == PART_DRAW_REND) ? part->ren_as : part->draw_as;
-				if (draw_as != PART_DRAW_PATH) {
-					continue;
-				}
-
-				DRWShadingGroup *shgrp = NULL;
-				Material *ma = give_current_material(ob, part->omat);
-
-				if (ma == NULL) {
-					ma = &defmaterial;
-				}
-
-				float *color_p = &ma->r;
-				float *metal_p = &ma->metallic;
-				float *spec_p = &ma->spec;
-				float *rough_p = &ma->roughness;
-
-				shgrp = DRW_shgroup_hair_create(
-				        ob, psys, md,
-				        psl->depth_pass,
-				        e_data.default_hair_prepass_sh);
-
-				shgrp = DRW_shgroup_hair_create(
-				        ob, psys, md,
-				        psl->depth_pass_clip,
-				        e_data.default_hair_prepass_clip_sh);
-				DRW_shgroup_uniform_block(shgrp, "clip_block", sldata->clip_ubo);
-
-				shgrp = NULL;
-				if (ma->use_nodes && ma->nodetree) {
-					static int ssr_id;
-					ssr_id = (use_ssr) ? 1 : -1;
-					static float half = 0.5f;
-					static float error_col[3] = {1.0f, 0.0f, 1.0f};
-					static float compile_col[3] = {0.5f, 0.5f, 0.5f};
-					struct GPUMaterial *gpumat = EEVEE_material_hair_get(scene, ma, sldata->lamps->shadow_method);
-
-					switch (GPU_material_status(gpumat)) {
-						case GPU_MAT_SUCCESS:
-						{
-							bool use_diffuse = GPU_material_flag_get(gpumat, GPU_MATFLAG_DIFFUSE);
-							bool use_glossy = GPU_material_flag_get(gpumat, GPU_MATFLAG_GLOSSY);
-							bool use_refract = GPU_material_flag_get(gpumat, GPU_MATFLAG_REFRACT);
-
-							shgrp = DRW_shgroup_material_hair_create(
-							        ob, psys, md,
-							        psl->material_pass,
-							        gpumat);
-
-							add_standard_uniforms(shgrp, sldata, vedata, &ssr_id, NULL,
-							                      use_diffuse, use_glossy, use_refract, false, false);
-							break;
-						}
-						case GPU_MAT_QUEUED:
-						{
-							color_p = compile_col;
-							metal_p = spec_p = rough_p = ½
-							break;
-						}
-						case GPU_MAT_FAILED:
-						default:
-							color_p = error_col;
-							metal_p = spec_p = rough_p = ½
-							break;
-					}
-				}
-
-				/* Fallback to default shader */
-				if (shgrp == NULL) {
-					shgrp = EEVEE_default_shading_group_get(sldata, vedata,
-					                                        ob, psys, md,
-					                                        true, false, use_ssr,
-					                                        sldata->lamps->shadow_method);
-					DRW_shgroup_uniform_vec3(shgrp, "basecol", color_p, 1);
-					DRW_shgroup_uniform_float(shgrp, "metallic", metal_p, 1);
-					DRW_shgroup_uniform_float(shgrp, "specular", spec_p, 1);
-					DRW_shgroup_uniform_float(shgrp, "roughness", rough_p, 1);
-				}
-
-				/* Shadows */
-				DRW_shgroup_hair_create(
-				        ob, psys, md,
-				        psl->shadow_pass,
-				        e_data.default_hair_prepass_sh);
-				*cast_shadow = true;
 			}
 		}
 	}

source/blender/draw/engines/workbench/shaders/workbench_prepass_vert.glsl

@@ -23,6 +23,8 @@ out vec3 normal_viewport;
 out vec2 uv_interp;
 #endif
 
+out int DEBUG;
+
 /* From http://libnoise.sourceforge.net/noisegen/index.html */
 float integer_noise(int n)
 {
@@ -34,6 +36,7 @@ float integer_noise(int n)
 void main()
 {
 #ifdef HAIR_SHADER
+	DEBUG = hair_get_strand_id();
 #  ifdef V3D_SHADING_TEXTURE_COLOR
 	vec2 uv = hair_get_customdata_vec2(u);
 #  endif

source/blender/draw/engines/workbench/workbench_deferred.c

@@ -633,7 +633,7 @@ static void workbench_cache_populate_particles(WORKBENCH_Data *vedata, Object *o
 			struct GPUShader *shader = (color_type != V3D_SHADING_TEXTURE_COLOR) ?
 			        wpd->prepass_solid_hair_sh :
 			        wpd->prepass_texture_hair_sh;
-			DRWShadingGroup *shgrp = DRW_shgroup_hair_create(
+			DRWShadingGroup *shgrp = DRW_shgroup_particle_hair_create(
 			        ob, psys, md,
 			        psl->prepass_hair_pass,
 			        shader);

source/blender/draw/engines/workbench/workbench_forward.c

@@ -425,7 +425,7 @@ static void workbench_forward_cache_populate_particles(WORKBENCH_Data *vedata, O
 			struct GPUShader *shader = (color_type != V3D_SHADING_TEXTURE_COLOR)
 			                           ? wpd->transparent_accum_hair_sh
 			                           : wpd->transparent_accum_texture_hair_sh;
-			DRWShadingGroup *shgrp = DRW_shgroup_hair_create(
+			DRWShadingGroup *shgrp = DRW_shgroup_particle_hair_create(
 			                                ob, psys, md,
 			                                psl->transparent_accum_pass,
 			                                shader);
@@ -444,7 +444,7 @@ static void workbench_forward_cache_populate_particles(WORKBENCH_Data *vedata, O
 			if (SPECULAR_HIGHLIGHT_ENABLED(wpd) || MATCAP_ENABLED(wpd)) {
 				DRW_shgroup_uniform_vec2(shgrp, "invertedViewportSize", DRW_viewport_invert_size_get(), 1);
 			}
-			shgrp = DRW_shgroup_hair_create(ob, psys, md,
+			shgrp = DRW_shgroup_particle_hair_create(ob, psys, md,
 			                        vedata->psl->object_outline_pass,
 			                        e_data.object_outline_hair_sh);
 			DRW_shgroup_uniform_int(shgrp, "object_id", &material->object_id, 1);

source/blender/draw/intern/draw_cache.c

@@ -3366,6 +3366,20 @@ GPUBatch *DRW_cache_particles_get_prim(int type)
 	return NULL;
 }
 
+/* -------------------------------------------------------------------- */
+
+/** \name Hair */
+
+GPUBatch *DRW_cache_hair_get_fibers(struct HairSystem *hsys, const struct HairExportCache *hair_export)
+{
+	return DRW_hair_batch_cache_get_fibers(hsys, hair_export);
+}
+
+GPUBatch *DRW_cache_hair_get_follicle_points(struct HairSystem *hsys, const struct HairExportCache *hair_export)
+{
+	return DRW_hair_batch_cache_get_follicle_points(hsys, hair_export);
+}
+
 /* 3D cursor */
 GPUBatch *DRW_cache_cursor_get(bool crosshair_lines)
 {

source/blender/draw/intern/draw_cache.h

@@ -31,6 +31,8 @@ struct GPUMaterial;
 struct ModifierData;
 struct Object;
 struct PTCacheEdit;
+struct HairSystem;
+struct HairExportCache;
 
 void DRW_shape_cache_free(void);
 void DRW_shape_cache_reset(void);
@@ -193,6 +195,10 @@ struct GPUBatch *DRW_cache_particles_get_edit_tip_points(
         struct Object *object, struct ParticleSystem *psys, struct PTCacheEdit *edit);
 struct GPUBatch *DRW_cache_particles_get_prim(int type);
 
+/* Hair */
+struct GPUBatch *DRW_cache_hair_get_fibers(struct HairSystem *hsys, const struct HairExportCache *hair_export);
+struct GPUBatch *DRW_cache_hair_get_follicle_points(struct HairSystem *hsys, const struct HairExportCache *hair_export);
+
 /* Metaball */
 struct GPUBatch *DRW_cache_mball_surface_get(struct Object *ob);
 struct GPUBatch **DRW_cache_mball_surface_shaded_get(struct Object *ob, struct GPUMaterial **gpumat_array, uint gpumat_array_len);

source/blender/draw/intern/draw_cache_impl.h

@@ -36,6 +36,8 @@ struct ListBase;
 struct ModifierData;
 struct ParticleSystem;
 struct PTCacheEdit;
+struct HairSystem;
+struct HairExportCache;
 
 struct Curve;
 struct Lattice;
@@ -62,6 +64,9 @@ void DRW_particle_batch_cache_free(struct ParticleSystem *psys);
 void DRW_gpencil_batch_cache_dirty(struct bGPdata *gpd);
 void DRW_gpencil_batch_cache_free(struct bGPdata *gpd);
 
+void DRW_hair_batch_cache_dirty(struct HairSystem *hsys, int mode);
+void DRW_hair_batch_cache_free(struct HairSystem *hsys);
+
 /* Curve */
 struct GPUBatch *DRW_curve_batch_cache_get_wire_edge(struct Curve *cu, struct CurveCache *ob_curve_cache);
 struct GPUBatch *DRW_curve_batch_cache_get_normal_edge(
@@ -146,4 +151,8 @@ struct GPUBatch *DRW_particles_batch_cache_get_edit_inner_points(
 struct GPUBatch *DRW_particles_batch_cache_get_edit_tip_points(
         struct Object *object, struct ParticleSystem *psys, struct PTCacheEdit *edit);
 
+/* Hair */
+struct GPUBatch *DRW_hair_batch_cache_get_fibers(struct HairSystem *hsys, const struct HairExportCache *hair_export);
+struct GPUBatch *DRW_hair_batch_cache_get_follicle_points(struct HairSystem *hsys, const struct HairExportCache *hair_export);
+
 #endif /* __DRAW_CACHE_IMPL_H__ */

source/blender/draw/intern/draw_cache_impl_hair.c

@@ -0,0 +1,556 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2017 by Blender Foundation.
+ * All rights reserved.
+ *
+ * Contributor(s): Blender Foundation, Mike Erwin, Dalai Felinto
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file draw_cache_impl_strands.c
+ *  \ingroup draw
+ *
+ * \brief Strands API for render engines
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_utildefines.h"
+#include "BLI_math_vector.h"
+#include "BLI_ghash.h"
+
+#include "DNA_hair_types.h"
+#include "DNA_scene_types.h"
+
+#include "BKE_hair.h"
+#include "BKE_mesh_sample.h"
+
+#include "DEG_depsgraph.h"
+
+#include "GPU_batch.h"
+#include "GPU_extensions.h"
+#include "GPU_texture.h"
+
+#include "draw_common.h"
+#include "draw_cache_impl.h"  /* own include */
+#include "draw_hair_private.h"
+
+#include "DRW_render.h"
+
+/* ---------------------------------------------------------------------- */
+/* Hair GPUBatch Cache */
+
+/* GPUBatch cache management. */
+
+typedef struct HairBatchCache {
+	ParticleHairCache hair;
+
+	bool is_dirty;
+} HairBatchCache;
+
+static void hair_batch_cache_clear(HairSystem *hsys);
+
+static bool hair_batch_cache_valid(HairSystem *hsys)
+{
+	HairBatchCache *cache = hsys->draw_batch_cache;
+
+	if (cache == NULL) {
+		return false;
+	}
+
+	if (cache->is_dirty) {
+		return false;
+	}
+
+	return true;
+}
+
+static void hair_batch_cache_init(HairSystem *hsys)
+{
+	HairBatchCache *cache = hsys->draw_batch_cache;
+	
+	if (!cache) {
+		cache = hsys->draw_batch_cache = MEM_callocN(sizeof(*cache), __func__);
+	}
+	else {
+		memset(cache, 0, sizeof(*cache));
+	}
+	
+	cache->is_dirty = false;
+}
+
+static HairBatchCache *hair_batch_cache_get(HairSystem *hsys)
+{
+	// Hair follicle binding needs to be updated after changes
+	BLI_assert(!(hsys->flag & HAIR_SYSTEM_UPDATE_FOLLICLE_BINDING));
+	
+	if (!hair_batch_cache_valid(hsys)) {
+		hair_batch_cache_clear(hsys);
+		hair_batch_cache_init(hsys);
+	}
+	return hsys->draw_batch_cache;
+}
+
+void DRW_hair_batch_cache_dirty(HairSystem *hsys, int mode)
+{
+	HairBatchCache *cache = hsys->draw_batch_cache;
+	if (cache == NULL) {
+		return;
+	}
+	switch (mode) {
+		case BKE_HAIR_BATCH_DIRTY_ALL:
+			cache->is_dirty = true;
+			break;
+		default:
+			BLI_assert(0);
+	}
+}
+
+static void hair_batch_cache_clear(HairSystem *hsys)
+{
+	HairBatchCache *cache = hsys->draw_batch_cache;
+	if (cache) {
+		particle_batch_cache_clear_hair(&cache->hair);
+	}
+}
+
+void DRW_hair_batch_cache_free(HairSystem *hsys)
+{
+	hair_batch_cache_clear(hsys);
+	MEM_SAFE_FREE(hsys->draw_batch_cache);
+}
+
+static void hair_batch_cache_ensure_count(
+        const HairExportCache *hair_export,
+        ParticleHairCache *cache)
+{
+    cache->strands_len = hair_export->totfollicles;
+    cache->elems_len = hair_export->totverts - hair_export->totcurves;
+    cache->point_len = hair_export->totverts;
+}
+
+static void hair_batch_cache_fill_segments_proc_pos(
+        const HairExportCache *hair_export,
+        GPUVertBufRaw *attr_step)
+{
+	for (int i = 0; i < hair_export->totcurves; i++) {
+		const HairFiberCurve *curve = &hair_export->fiber_curves[i];
+		const HairFiberVertex *verts = &hair_export->fiber_verts[curve->vertstart];
+		if (curve->numverts < 2) {
+			continue;
+		}
+		float total_len = 0.0f;
+		const float *co_prev = NULL;
+		float *seg_data_first;
+		for (int j = 0; j < curve->numverts; j++) {
+			float *seg_data = (float *)GPU_vertbuf_raw_step(attr_step);
+			copy_v3_v3(seg_data, verts[j].co);
+			if (co_prev) {
+				total_len += len_v3v3(co_prev, verts[j].co);
+			}
+			else {
+				seg_data_first = seg_data;
+			}
+			seg_data[3] = total_len;
+			co_prev = verts[j].co;
+		}
+		if (total_len > 0.0f) {
+			/* Divide by total length to have a [0-1] number. */
+			for (int j = 0; j < curve->numverts; j++, seg_data_first += 4) {
+				seg_data_first[3] /= total_len;
+			}
+		}
+	}
+}
+
+static void hair_batch_cache_ensure_procedural_pos(
+        const HairExportCache *hair_export,
+        ParticleHairCache *cache)
+{
+	if (cache->proc_point_buf != NULL) {
+		return;
+	}
+
+	/* initialize vertex format */
+	GPUVertFormat format = {0};
+	uint pos_id = GPU_vertformat_attr_add(&format, "posTime", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
+
+	cache->proc_point_buf = GPU_vertbuf_create_with_format(&format);
+	GPU_vertbuf_data_alloc(cache->proc_point_buf, cache->point_len);
+
+	GPUVertBufRaw pos_step;
+	GPU_vertbuf_attr_get_raw_data(cache->proc_point_buf, pos_id, &pos_step);
+
+	hair_batch_cache_fill_segments_proc_pos(hair_export, &pos_step);
+
+	/* Create vbo immediatly to bind to texture buffer. */
+	GPU_vertbuf_use(cache->proc_point_buf);
+
+	cache->point_tex = GPU_texture_create_from_vertbuf(cache->proc_point_buf);
+}
+
+static void hair_pack_mcol(MCol *mcol, unsigned short r_scol[3])
+{
+	/* Convert to linear ushort and swizzle */
+	r_scol[0] = unit_float_to_ushort_clamp(BLI_color_from_srgb_table[mcol->b]);
+	r_scol[1] = unit_float_to_ushort_clamp(BLI_color_from_srgb_table[mcol->g]);
+	r_scol[2] = unit_float_to_ushort_clamp(BLI_color_from_srgb_table[mcol->r]);
+}
+
+static int hair_batch_cache_fill_strands_data(
+        const HairExportCache *hair_export,
+        GPUVertBufRaw *data_step,
+        GPUVertBufRaw *uv_step, int num_uv_layers,
+        GPUVertBufRaw *col_step, int num_col_layers)
+{
+	int curr_point = 0;
+	for (int i = 0; i < hair_export->totcurves; i++) {
+		const HairFiberCurve *curve = &hair_export->fiber_curves[i];
+		if (curve->numverts < 2) {
+			continue;
+		}
+
+		uint *seg_data = (uint *)GPU_vertbuf_raw_step(data_step);
+		const uint numseg = curve->numverts - 1;
+		*seg_data = (curr_point & 0xFFFFFF) | (numseg << 24);
+		curr_point += curve->numverts;
+
+		float (*uv)[2] = NULL;
+		MCol *mcol = NULL;
+		
+#if 0
+		particle_calculate_uvs(
+				psys, psmd,
+				is_simple, num_uv_layers,
+				is_child ? psys->child[i].parent : i,
+				is_child ? i : -1,
+				mtfaces,
+				*r_parent_uvs, &uv);
+
+		particle_calculate_mcol(
+				psys, psmd,
+				is_simple, num_col_layers,
+				is_child ? psys->child[i].parent : i,
+				is_child ? i : -1,
+				mcols,
+				*r_parent_mcol, &mcol);
+#else
+		/* XXX dummy uvs and mcols, TODO */
+		uv = MEM_mallocN(sizeof(*uv) * num_uv_layers, __func__);
+		mcol = MEM_mallocN(sizeof(*mcol) * num_col_layers, __func__);
+		for (int k = 0; k < num_uv_layers; k++) {
+			zero_v3(uv[k]);
+		}
+		for (int k = 0; k < num_col_layers; k++) {
+			mcol[k].a = 255;
+			mcol[k].r = 255;
+			mcol[k].g = 0;
+			mcol[k].b = 255;
+		}
+#endif
+		
+		for (int k = 0; k < num_uv_layers; k++) {
+			float *t_uv = (float *)GPU_vertbuf_raw_step(uv_step + k);
+			copy_v2_v2(t_uv, uv[k]);
+		}
+		for (int k = 0; k < num_col_layers; k++) {
+			unsigned short *scol = (unsigned short *)GPU_vertbuf_raw_step(col_step + k);
+			hair_pack_mcol(&mcol[k], scol);
+		}
+		
+		if (uv) {
+			MEM_freeN(uv);
+		}
+		if (mcol) {
+			MEM_freeN(mcol);
+		}
+	}
+	return curr_point;
+}
+
+static void hair_batch_cache_ensure_procedural_strand_data(
+        const HairExportCache *hair_export,
+        ParticleHairCache *cache)
+{
+	int active_uv = 0;
+	int active_col = 0;
+
+#if 0 // TODO
+	ParticleSystemModifierData *psmd = (ParticleSystemModifierData *)md;
+
+	if (psmd != NULL && psmd->mesh_final != NULL) {
+		if (CustomData_has_layer(&psmd->mesh_final->ldata, CD_MLOOPUV)) {
+			cache->num_uv_layers = CustomData_number_of_layers(&psmd->mesh_final->ldata, CD_MLOOPUV);
+			active_uv = CustomData_get_active_layer(&psmd->mesh_final->ldata, CD_MLOOPUV);
+		}
+		if (CustomData_has_layer(&psmd->mesh_final->ldata, CD_MLOOPCOL)) {
+			cache->num_col_layers = CustomData_number_of_layers(&psmd->mesh_final->ldata, CD_MLOOPCOL);
+			active_col = CustomData_get_active_layer(&psmd->mesh_final->ldata, CD_MLOOPCOL);
+		}
+	}
+#endif
+
+	GPUVertBufRaw data_step;
+	GPUVertBufRaw uv_step[MAX_MTFACE];
+	GPUVertBufRaw col_step[MAX_MCOL];
+
+	MTFace *mtfaces[MAX_MTFACE] = {NULL};
+	MCol *mcols[MAX_MCOL] = {NULL};
+
+	GPUVertFormat format_data = {0};
+	uint data_id = GPU_vertformat_attr_add(&format_data, "data", GPU_COMP_U32, 1, GPU_FETCH_INT);
+
+	GPUVertFormat format_uv = {0};
+	uint uv_id = GPU_vertformat_attr_add(&format_uv, "uv", GPU_COMP_F32, 2, GPU_FETCH_FLOAT);
+
+	GPUVertFormat format_col = {0};
+	uint col_id = GPU_vertformat_attr_add(&format_col, "col", GPU_COMP_U16, 4, GPU_FETCH_INT_TO_FLOAT_UNIT);
+
+	memset(cache->uv_layer_names, 0, sizeof(cache->uv_layer_names));
+	memset(cache->col_layer_names, 0, sizeof(cache->col_layer_names));
+
+	/* Strand Data */
+	cache->proc_strand_buf = GPU_vertbuf_create_with_format(&format_data);
+	GPU_vertbuf_data_alloc(cache->proc_strand_buf, cache->strands_len);
+	GPU_vertbuf_attr_get_raw_data(cache->proc_strand_buf, data_id, &data_step);
+
+#if 0 // TODO
+	/* UV layers */
+	for (int i = 0; i < cache->num_uv_layers; i++) {
+		cache->proc_uv_buf[i] = GPU_vertbuf_create_with_format(&format_uv);
+		GPU_vertbuf_data_alloc(cache->proc_uv_buf[i], cache->strands_len);
+		GPU_vertbuf_attr_get_raw_data(cache->proc_uv_buf[i], uv_id, &uv_step[i]);
+
+		const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPUV, i);
+		uint hash = BLI_ghashutil_strhash_p(name);
+		int n = 0;
+		BLI_snprintf(cache->uv_layer_names[i][n++], MAX_LAYER_NAME_LEN, "u%u", hash);
+		BLI_snprintf(cache->uv_layer_names[i][n++], MAX_LAYER_NAME_LEN, "a%u", hash);
+
+		if (i == active_uv) {
+			BLI_snprintf(cache->uv_layer_names[i][n], MAX_LAYER_NAME_LEN, "u");
+		}
+	}
+	/* Vertex colors */
+	for (int i = 0; i < cache->num_col_layers; i++) {
+		cache->proc_col_buf[i] = GPU_vertbuf_create_with_format(&format_col);
+		GPU_vertbuf_data_alloc(cache->proc_col_buf[i], cache->strands_len);
+		GPU_vertbuf_attr_get_raw_data(cache->proc_col_buf[i], col_id, &col_step[i]);
+
+		const char *name = CustomData_get_layer_name(&psmd->mesh_final->ldata, CD_MLOOPCOL, i);
+		uint hash = BLI_ghashutil_strhash_p(name);
+		int n = 0;
+		BLI_snprintf(cache->col_layer_names[i][n++], MAX_LAYER_NAME_LEN, "c%u", hash);
+
+		/* We only do vcols auto name that are not overridden by uvs */
+		if (CustomData_get_named_layer_index(&psmd->mesh_final->ldata, CD_MLOOPUV, name) == -1) {
+			BLI_snprintf(cache->col_layer_names[i][n++], MAX_LAYER_NAME_LEN, "a%u", hash);
+		}
+
+		if (i == active_col) {
+			BLI_snprintf(cache->col_layer_names[i][n], MAX_LAYER_NAME_LEN, "c");
+		}
+	}
+
+	if (cache->num_uv_layers || cache->num_col_layers) {
+		BKE_mesh_tessface_ensure(psmd->mesh_final);
+		if (cache->num_uv_layers) {
+			for (int j = 0; j < cache->num_uv_layers; j++) {
+				mtfaces[j] = (MTFace *)CustomData_get_layer_n(&psmd->mesh_final->fdata, CD_MTFACE, j);
+			}
+		}
+		if (cache->num_col_layers) {
+			for (int j = 0; j < cache->num_col_layers; j++) {
+				mcols[j] = (MCol *)CustomData_get_layer_n(&psmd->mesh_final->fdata, CD_MCOL, j);
+			}
+		}
+	}
+#endif
+
+	hair_batch_cache_fill_strands_data(
+	            hair_export,
+	            &data_step,
+	            uv_step, cache->num_uv_layers,
+	            col_step, cache->num_col_layers);
+
+	/* Create vbo immediatly to bind to texture buffer. */
+	GPU_vertbuf_use(cache->proc_strand_buf);
+	cache->strand_tex = GPU_texture_create_from_vertbuf(cache->proc_strand_buf);
+
+	for (int i = 0; i < cache->num_uv_layers; i++) {
+		GPU_vertbuf_use(cache->proc_uv_buf[i]);
+		cache->uv_tex[i] = GPU_texture_create_from_vertbuf(cache->proc_uv_buf[i]);
+	}
+	for (int i = 0; i < cache->num_col_layers; i++) {
+		GPU_vertbuf_use(cache->proc_col_buf[i]);
+		cache->col_tex[i] = GPU_texture_create_from_vertbuf(cache->proc_col_buf[i]);
+	}
+}
+
+static void hair_batch_cache_ensure_final_count(
+        const HairExportCache *hair_export,
+        ParticleHairFinalCache *cache,
+        int subdiv,
+        int thickness_res)
+{
+	const int totverts = hair_export->totverts;
+	const int totcurves = hair_export->totcurves;
+	cache->strands_len = hair_export->totfollicles;
+	/* +1 for primitive restart */
+	cache->elems_len = (((totverts - totcurves) << subdiv) + totcurves) * thickness_res;
+	cache->point_len = ((totverts - totcurves) << subdiv) + totcurves;
+}
+
+static void hair_batch_cache_ensure_procedural_final_points(
+        ParticleHairCache *cache,
+        int subdiv)
+{
+	/* Same format as point_tex. */
+	GPUVertFormat format = { 0 };
+	GPU_vertformat_attr_add(&format, "pos", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
+
+	cache->final[subdiv].proc_point_buf = GPU_vertbuf_create_with_format(&format);
+
+	/* Create a destination buffer for the tranform feedback. Sized appropriately */
+	/* Thoses are points! not line segments. */
+	GPU_vertbuf_data_alloc(cache->final[subdiv].proc_point_buf, cache->final[subdiv].point_len);
+
+	/* Create vbo immediatly to bind to texture buffer. */
+	GPU_vertbuf_use(cache->final[subdiv].proc_point_buf);
+
+	cache->final[subdiv].proc_tex = GPU_texture_create_from_vertbuf(cache->final[subdiv].proc_point_buf);
+}
+
+static int hair_batch_cache_fill_segments_indices(
+        const HairExportCache *hair_export,
+        const int subdiv,
+        const int thickness_res,
+        GPUIndexBufBuilder *elb)
+{
+	int curr_point = 0;
+	for (int i = 0; i < hair_export->totcurves; i++) {
+		const HairFiberCurve *curve = &hair_export->fiber_curves[i];
+		if (curve->numverts < 2) {
+			continue;
+		}
+
+		const int res = (((curve->numverts - 1) << subdiv) + 1) * thickness_res;
+		for (int k = 0; k < res; k++) {
+			GPU_indexbuf_add_generic_vert(elb, curr_point++);
+		}
+		GPU_indexbuf_add_primitive_restart(elb);
+	}
+	return curr_point;
+}
+
+static void hair_batch_cache_ensure_procedural_indices(
+        const HairExportCache *hair_export,
+        ParticleHairCache *cache,
+        int thickness_res,
+        int subdiv)
+{
+	BLI_assert(thickness_res <= MAX_THICKRES); /* Cylinder strip not currently supported. */
+
+	if (cache->final[subdiv].proc_hairs[thickness_res - 1] != NULL) {
+		return;
+	}
+
+	int element_count = cache->final[subdiv].elems_len;
+	GPUPrimType prim_type = (thickness_res == 1) ? GPU_PRIM_LINE_STRIP : GPU_PRIM_TRI_STRIP;
+
+	static GPUVertFormat format = { 0 };
+	GPU_vertformat_clear(&format);
+
+	/* initialize vertex format */
+	GPU_vertformat_attr_add(&format, "dummy", GPU_COMP_U8, 1, GPU_FETCH_INT_TO_FLOAT_UNIT);
+
+	GPUVertBuf *vbo = GPU_vertbuf_create_with_format(&format);
+	GPU_vertbuf_data_alloc(vbo, 1);
+
+	GPUIndexBufBuilder elb;
+	GPU_indexbuf_init_ex(&elb, prim_type, element_count, element_count, true);
+
+	hair_batch_cache_fill_segments_indices(hair_export, subdiv, thickness_res, &elb);
+
+	cache->final[subdiv].proc_hairs[thickness_res - 1] = GPU_batch_create_ex(
+	        prim_type,
+	        vbo,
+	        GPU_indexbuf_build(&elb),
+	        GPU_BATCH_OWNS_VBO | GPU_BATCH_OWNS_INDEX);
+}
+
+/* Ensure all textures and buffers needed for GPU accelerated drawing. */
+bool hair_ensure_procedural_data(
+        Object *UNUSED(object),
+        HairSystem *hsys,
+        struct Mesh *scalp,
+        ParticleHairCache **r_hair_cache,
+        int subdiv,
+        int thickness_res)
+{
+	bool need_ft_update = false;
+
+	HairExportCache *hair_export = BKE_hair_export_cache_new();
+	BKE_hair_export_cache_update(hair_export, hsys, subdiv, scalp, HAIR_EXPORT_ALL);
+
+	HairBatchCache *cache = hair_batch_cache_get(hsys);
+	*r_hair_cache = &cache->hair;
+
+	/* Refreshed on combing and simulation. */
+	if (cache->hair.proc_point_buf == NULL) {
+		hair_batch_cache_ensure_count(hair_export, &cache->hair);
+		
+		hair_batch_cache_ensure_procedural_pos(hair_export, &cache->hair);
+		need_ft_update = true;
+	}
+
+	/* Refreshed if active layer or custom data changes. */
+	if (cache->hair.strand_tex == NULL) {
+		hair_batch_cache_ensure_procedural_strand_data(hair_export, &cache->hair);
+	}
+
+	/* Refreshed only on subdiv count change. */
+	if (cache->hair.final[subdiv].proc_point_buf == NULL) {
+		hair_batch_cache_ensure_final_count(hair_export, &cache->hair.final[subdiv], subdiv, thickness_res);
+		
+		hair_batch_cache_ensure_procedural_final_points(&cache->hair, subdiv);
+		need_ft_update = true;
+	}
+	if (cache->hair.final[subdiv].proc_hairs[thickness_res - 1] == NULL) {
+		hair_batch_cache_ensure_procedural_indices(hair_export, &cache->hair, thickness_res, subdiv);
+	}
+
+	BKE_hair_export_cache_free(hair_export);
+
+	return need_ft_update;
+}
+
+GPUBatch *DRW_hair_batch_cache_get_fibers(HairSystem *hsys, const HairExportCache *hair_export)
+{
+	// TODO
+	UNUSED_VARS(hsys, hair_export);
+	return NULL;
+}
+
+GPUBatch *DRW_hair_batch_cache_get_follicle_points(HairSystem *hsys, const HairExportCache *hair_export)
+{
+	// TODO
+	UNUSED_VARS(hsys, hair_export);
+	return NULL;
+}

source/blender/draw/intern/draw_cache_impl_particles.c

@@ -162,37 +162,6 @@ static void particle_batch_cache_clear_point(ParticlePointCache *point_cache)
 	GPU_VERTBUF_DISCARD_SAFE(point_cache->pos);
 }
 
-static void particle_batch_cache_clear_hair(ParticleHairCache *hair_cache)
-{
-	/* TODO more granular update tagging. */
-	GPU_VERTBUF_DISCARD_SAFE(hair_cache->proc_point_buf);
-	DRW_TEXTURE_FREE_SAFE(hair_cache->point_tex);
-
-	GPU_VERTBUF_DISCARD_SAFE(hair_cache->proc_strand_buf);
-	DRW_TEXTURE_FREE_SAFE(hair_cache->strand_tex);
-
-	for (int i = 0; i < MAX_MTFACE; ++i) {
-		GPU_VERTBUF_DISCARD_SAFE(hair_cache->proc_uv_buf[i]);
-		DRW_TEXTURE_FREE_SAFE(hair_cache->uv_tex[i]);
-	}
-	for (int i = 0; i < MAX_MCOL; ++i) {
-		GPU_VERTBUF_DISCARD_SAFE(hair_cache->proc_col_buf[i]);
-		DRW_TEXTURE_FREE_SAFE(hair_cache->col_tex[i]);
-	}
-	for (int i = 0; i < MAX_HAIR_SUBDIV; ++i) {
-		GPU_VERTBUF_DISCARD_SAFE(hair_cache->final[i].proc_buf);
-		DRW_TEXTURE_FREE_SAFE(hair_cache->final[i].proc_tex);
-		for (int j = 0; j < MAX_THICKRES; ++j) {
-			GPU_BATCH_DISCARD_SAFE(hair_cache->final[i].proc_hairs[j]);
-		}
-	}
-
-	/* "Normal" legacy hairs */
-	GPU_BATCH_DISCARD_SAFE(hair_cache->hairs);
-	GPU_VERTBUF_DISCARD_SAFE(hair_cache->pos);
-	GPU_INDEXBUF_DISCARD_SAFE(hair_cache->indices);
-}
-
 static void particle_batch_cache_clear(ParticleSystem *psys)
 {
 	ParticleBatchCache *cache = psys->batch_cache;
@@ -654,19 +623,26 @@ static void particle_batch_cache_fill_segments_proc_pos(
 }
 
 static int particle_batch_cache_fill_segments_indices(
+        const ParticleSystem *psys,
         ParticleCacheKey **path_cache,
         const int start_index,
         const int num_path_keys,
-        const int res,
+        const int subdiv,
+        const int thickness_res,
         GPUIndexBufBuilder *elb)
 {
+	const ParticleSettings *part = psys->part;
+	const int points_per_curve = (1 << (part->draw_step + subdiv)) + 1;
+	const int points_per_hair = points_per_curve * thickness_res;
+	
 	int curr_point = start_index;
 	for (int i = 0; i < num_path_keys; i++) {
 		ParticleCacheKey *path = path_cache[i];
 		if (path->segments <= 0) {
 			continue;
 		}
-		for (int k = 0; k < res; k++) {
+		
+		for (int k = 0; k < points_per_hair; k++) {
 			GPU_indexbuf_add_generic_vert(elb, curr_point++);
 		}
 		GPU_indexbuf_add_primitive_restart(elb);
@@ -749,24 +725,93 @@ static int particle_batch_cache_fill_strands_data(
 	return curr_point;
 }
 
+static void ensure_seg_pt_final_count(
+        const ParticleSystem *psys,
+        ParticleHairCache *hair_cache,
+        int subdiv,
+        int thickness_res)
+{
+	ParticleHairFinalCache *final_cache = &hair_cache->final[subdiv];
+	
+	const ParticleSettings *part = psys->part;
+	const int points_per_curve = (1 << (part->draw_step + subdiv)) + 1;
+
+	final_cache->strands_len = hair_cache->strands_len;
+	final_cache->point_len = points_per_curve * final_cache->strands_len;
+	
+	/* +1 for primitive restart */
+	final_cache->elems_len = (points_per_curve * thickness_res + 1) * final_cache->strands_len;
+}
+
+#define USE_POSITION_HAIR_INDEX
+
 static void particle_batch_cache_ensure_procedural_final_points(
+        const ParticleSystem *psys,
+        ParticleHairCache *cache,
+        int subdiv)
+{
+
+	/* Same format as point_tex. */
+#ifdef USE_POSITION_HAIR_INDEX
+	static GPUVertFormat format = { 0 };
+	GPU_vertformat_clear(&format);
+	uint pos_id = GPU_vertformat_attr_add(&format, "pos", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
+#else
+	static GPUVer format = { 0 };
+	GPU_vertformat_attr_add(&format, "pos", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
+#endif
+
+	cache->final[subdiv].proc_point_buf = GPU_vertbuf_create_with_format(&format);
+
+	/* Create a destination buffer for the tranform feedback. Sized appropriately */
+	/* Thoses are points! not line segments. */
+	GPU_vertbuf_data_alloc(cache->final[subdiv].proc_point_buf, cache->final[subdiv].point_len);
+
+#ifdef USE_POSITION_HAIR_INDEX
+	GPUVertBufRaw data_step;
+	GPU_vertbuf_attr_get_raw_data(cache->final[subdiv].proc_point_buf, pos_id, &data_step);
+	const int points_per_curve = (1 << (psys->part->draw_step + subdiv)) + 1;
+	for (int i = 0; i < cache->final[subdiv].strands_len; i++) {
+		for (int j = 0; j < points_per_curve; ++j) {
+			uint *data = (uint *)GPU_vertbuf_raw_step(&data_step);
+			*data = (uint)i;
+		}
+	}
+#endif
+
+	/* Create vbo immediatly to bind to texture buffer. */
+	GPU_vertbuf_use(cache->final[subdiv].proc_point_buf);
+
+	cache->final[subdiv].proc_tex = GPU_texture_create_from_vertbuf(cache->final[subdiv].proc_point_buf);
+}
+
+static void particle_batch_cache_ensure_procedural_final_hair_index(
+        const ParticleSystem *psys,
         ParticleHairCache *cache,
         int subdiv)
 {
 	/* Same format as point_tex. */
 	GPUVertFormat format = { 0 };
-	GPU_vertformat_attr_add(&format, "pos", GPU_COMP_F32, 4, GPU_FETCH_FLOAT);
+	uint hair_index_id = GPU_vertformat_attr_add(&format, "hair_index", GPU_COMP_U32, 1, GPU_FETCH_INT);
 
-	cache->final[subdiv].proc_buf = GPU_vertbuf_create_with_format(&format);
+	cache->final[subdiv].proc_hair_index_buf = GPU_vertbuf_create_with_format(&format);
 
-	/* Create a destination buffer for the tranform feedback. Sized appropriately */
-	/* Thoses are points! not line segments. */
-	GPU_vertbuf_data_alloc(cache->final[subdiv].proc_buf, cache->final[subdiv].strands_res * cache->strands_len);
+	GPU_vertbuf_data_alloc(cache->final[subdiv].proc_hair_index_buf, cache->final[subdiv].point_len);
+
+	GPUVertBufRaw data_step;
+	GPU_vertbuf_attr_get_raw_data(cache->final[subdiv].proc_hair_index_buf, hair_index_id, &data_step);
+	const int points_per_curve = (1 << (psys->part->draw_step + subdiv)) + 1;
+	for (int i = 0; i < cache->final[subdiv].strands_len; i++) {
+		for (int j = 0; j < points_per_curve; ++j) {
+			uint *data = (uint *)GPU_vertbuf_raw_step(&data_step);
+			*data = (uint)i;
+		}
+	}
 
 	/* Create vbo immediatly to bind to texture buffer. */
-	GPU_vertbuf_use(cache->final[subdiv].proc_buf);
+	GPU_vertbuf_use(cache->final[subdiv].proc_hair_index_buf);
 
-	cache->final[subdiv].proc_tex = GPU_texture_create_from_vertbuf(cache->final[subdiv].proc_buf);
+	cache->final[subdiv].hair_index_tex = GPU_texture_create_from_vertbuf(cache->final[subdiv].proc_hair_index_buf);
 }
 
 static void particle_batch_cache_ensure_procedural_strand_data(
@@ -940,9 +985,7 @@ static void particle_batch_cache_ensure_procedural_indices(
 		return;
 	}
 
-	int verts_per_hair = cache->final[subdiv].strands_res * thickness_res;
-	/* +1 for primitive restart */
-	int element_count = (verts_per_hair + 1) * cache->strands_len;
+	int element_count = cache->final[subdiv].elems_len;
 	GPUPrimType prim_type = (thickness_res == 1) ? GPU_PRIM_LINE_STRIP : GPU_PRIM_TRI_STRIP;
 
 	static GPUVertFormat format = { 0 };
@@ -959,7 +1002,7 @@ static void particle_batch_cache_ensure_procedural_indices(
 
 	if (edit != NULL && edit->pathcache != NULL) {
 		particle_batch_cache_fill_segments_indices(
-		        edit->pathcache, 0, edit->totcached, verts_per_hair, &elb);
+		        psys, edit->pathcache, 0, edit->totcached, subdiv, thickness_res, &elb);
 	}
 	else {
 		int curr_point = 0;
@@ -967,12 +1010,12 @@ static void particle_batch_cache_ensure_procedural_indices(
 		    (!psys->childcache || (psys->part->draw & PART_DRAW_PARENT)))
 		{
 			curr_point = particle_batch_cache_fill_segments_indices(
-			        psys->pathcache, 0, psys->totpart, verts_per_hair, &elb);
+			        psys, psys->pathcache, 0, psys->totpart, subdiv, thickness_res, &elb);
 		}
 		if (psys->childcache) {
 			const int child_count = psys->totchild * psys->part->disp / 100;
 			curr_point = particle_batch_cache_fill_segments_indices(
-			        psys->childcache, curr_point, child_count, verts_per_hair, &elb);
+			        psys, psys->childcache, curr_point, child_count, subdiv, thickness_res, &elb);
 		}
 	}
 
@@ -1555,12 +1598,9 @@ bool particles_ensure_procedural_data(
 	ParticleDrawSource source;
 	drw_particle_get_hair_source(object, psys, md, NULL, &source);
 
-	ParticleSettings *part = source.psys->part;
 	ParticleBatchCache *cache = particle_batch_cache_get(source.psys);
 	*r_hair_cache = &cache->hair;
 
-	(*r_hair_cache)->final[subdiv].strands_res = 1 << (part->draw_step + subdiv);
-
 	/* Refreshed on combing and simulation. */
 	if ((*r_hair_cache)->proc_point_buf == NULL) {
 		ensure_seg_pt_count(source.edit, source.psys, &cache->hair);
@@ -1574,8 +1614,10 @@ bool particles_ensure_procedural_data(
 	}
 
 	/* Refreshed only on subdiv count change. */
-	if ((*r_hair_cache)->final[subdiv].proc_buf == NULL) {
-		particle_batch_cache_ensure_procedural_final_points(&cache->hair, subdiv);
+	if ((*r_hair_cache)->final[subdiv].proc_point_buf == NULL) {
+		ensure_seg_pt_final_count(psys, &cache->hair, subdiv, thickness_res);
+		particle_batch_cache_ensure_procedural_final_points(psys, &cache->hair, subdiv);
+		particle_batch_cache_ensure_procedural_final_hair_index(psys, &cache->hair, subdiv);
 		need_ft_update = true;
 	}
 	if ((*r_hair_cache)->final[subdiv].proc_hairs[thickness_res - 1] == NULL) {

source/blender/draw/intern/draw_common.h

@@ -26,11 +26,17 @@
 #ifndef __DRAW_COMMON_H__
 #define __DRAW_COMMON_H__
 
+struct Mesh;
 struct DRWPass;
 struct DRWShadingGroup;
 struct GPUBatch;
 struct GPUMaterial;
+struct GPUShader;
+struct GPUTexture;
+struct HairDrawSettings;
+struct HairSystem;
 struct Object;
+struct Scene;
 struct ViewLayer;
 struct ModifierData;
 struct ParticleSystem;
@@ -162,16 +168,28 @@ void DRW_shgroup_armature_edit(struct Object *ob, struct DRWArmaturePasses passe
 
 /* This creates a shading group with display hairs.
  * The draw call is already added by this function, just add additional uniforms. */
-struct DRWShadingGroup *DRW_shgroup_hair_create(
+struct DRWShadingGroup *DRW_shgroup_particle_hair_create(
         struct Object *object, struct ParticleSystem *psys, struct ModifierData *md,
         struct DRWPass *hair_pass,
         struct GPUShader *shader);
 
-struct DRWShadingGroup *DRW_shgroup_material_hair_create(
+struct DRWShadingGroup *DRW_shgroup_material_particle_hair_create(
         struct Object *object, struct ParticleSystem *psys, struct ModifierData *md,
         struct DRWPass *hair_pass,
         struct GPUMaterial *material);
 
+struct DRWShadingGroup *DRW_shgroup_hair_create(
+        struct Object *object, struct HairSystem *hsys,
+        struct Mesh *scalp, const struct HairDrawSettings *draw_set,
+        struct DRWPass *hair_pass,
+        struct GPUShader *shader);
+
+struct DRWShadingGroup *DRW_shgroup_material_hair_create(
+        struct Object *object, struct HairSystem *hsys,
+        struct Mesh *scalp, const struct HairDrawSettings *draw_set,
+        struct DRWPass *hair_pass,
+        struct GPUMaterial *material);
+
 void DRW_hair_init(void);
 void DRW_hair_update(void);
 void DRW_hair_free(void);

source/blender/draw/intern/draw_hair.c

@@ -34,12 +34,14 @@
 #include "BLI_utildefines.h"
 #include "BLI_string_utils.h"
 
+#include "DNA_hair_types.h"
 #include "DNA_mesh_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_particle_types.h"
 #include "DNA_customdata_types.h"
 
+#include "BKE_hair.h"
 #include "BKE_mesh.h"
 #include "BKE_particle.h"
 #include "BKE_pointcache.h"
@@ -85,7 +87,38 @@ void DRW_hair_init(void)
 	g_tf_pass = DRW_pass_create("Update Hair Pass", DRW_STATE_TRANS_FEEDBACK);
 }
 
-static DRWShadingGroup *drw_shgroup_create_hair_procedural_ex(
+void particle_batch_cache_clear_hair(ParticleHairCache *hair_cache)
+{
+	/* TODO more granular update tagging. */
+	GPU_VERTBUF_DISCARD_SAFE(hair_cache->proc_point_buf);
+	DRW_TEXTURE_FREE_SAFE(hair_cache->point_tex);
+
+	GPU_VERTBUF_DISCARD_SAFE(hair_cache->proc_strand_buf);
+	DRW_TEXTURE_FREE_SAFE(hair_cache->strand_tex);
+
+	for (int i = 0; i < MAX_MTFACE; ++i) {
+		GPU_VERTBUF_DISCARD_SAFE(hair_cache->proc_uv_buf[i]);
+		DRW_TEXTURE_FREE_SAFE(hair_cache->uv_tex[i]);
+	}
+	for (int i = 0; i < MAX_MCOL; ++i) {
+		GPU_VERTBUF_DISCARD_SAFE(hair_cache->proc_col_buf[i]);
+		DRW_TEXTURE_FREE_SAFE(hair_cache->col_tex[i]);
+	}
+	for (int i = 0; i < MAX_HAIR_SUBDIV; ++i) {
+		GPU_VERTBUF_DISCARD_SAFE(hair_cache->final[i].proc_point_buf);
+		DRW_TEXTURE_FREE_SAFE(hair_cache->final[i].proc_tex);
+		for (int j = 0; j < MAX_THICKRES; ++j) {
+			GPU_BATCH_DISCARD_SAFE(hair_cache->final[i].proc_hairs[j]);
+		}
+	}
+
+	/* "Normal" legacy hairs */
+	GPU_BATCH_DISCARD_SAFE(hair_cache->hairs);
+	GPU_VERTBUF_DISCARD_SAFE(hair_cache->pos);
+	GPU_INDEXBUF_DISCARD_SAFE(hair_cache->indices);
+}
+
+static DRWShadingGroup *drw_shgroup_create_particle_hair_procedural_ex(
         Object *object, ParticleSystem *psys, ModifierData *md,
         DRWPass *hair_pass,
         struct GPUMaterial *gpu_mat, GPUShader *gpu_shader)
@@ -126,7 +159,7 @@ static DRWShadingGroup *drw_shgroup_create_hair_procedural_ex(
 	}
 
 	DRW_shgroup_uniform_texture(shgrp, "hairPointBuffer", hair_cache->final[subdiv].proc_tex);
-	DRW_shgroup_uniform_int(shgrp, "hairStrandsRes", &hair_cache->final[subdiv].strands_res, 1);
+	DRW_shgroup_uniform_texture(shgrp, "hairIndexBuffer", hair_cache->final[subdiv].hair_index_tex);
 	DRW_shgroup_uniform_int_copy(shgrp, "hairThicknessRes", thickness_res);
 	DRW_shgroup_uniform_float(shgrp, "hairRadShape", &part->shape, 1);
 	DRW_shgroup_uniform_float_copy(shgrp, "hairRadRoot", part->rad_root * part->rad_scale * 0.5f);
@@ -137,33 +170,110 @@ static DRWShadingGroup *drw_shgroup_create_hair_procedural_ex(
 
 	/* Transform Feedback subdiv. */
 	if (need_ft_update) {
-		int final_points_len = hair_cache->final[subdiv].strands_res * hair_cache->strands_len;
 		GPUShader *tf_shader = hair_refine_shader_get(PART_REFINE_CATMULL_ROM);
 		DRWShadingGroup *tf_shgrp = DRW_shgroup_transform_feedback_create(tf_shader, g_tf_pass,
-		                                                                  hair_cache->final[subdiv].proc_buf);
+		                                                                  hair_cache->final[subdiv].proc_point_buf);
 		DRW_shgroup_uniform_texture(tf_shgrp, "hairPointBuffer", hair_cache->point_tex);
 		DRW_shgroup_uniform_texture(tf_shgrp, "hairStrandBuffer", hair_cache->strand_tex);
-		DRW_shgroup_uniform_int(tf_shgrp, "hairStrandsRes", &hair_cache->final[subdiv].strands_res, 1);
-		DRW_shgroup_call_procedural_points_add(tf_shgrp, final_points_len, NULL);
+		DRW_shgroup_call_procedural_points_add(tf_shgrp, hair_cache->final[subdiv].point_len, NULL);
 	}
 
 	return shgrp;
 }
 
-DRWShadingGroup *DRW_shgroup_hair_create(
+DRWShadingGroup *DRW_shgroup_particle_hair_create(
         Object *object, ParticleSystem *psys, ModifierData *md,
         DRWPass *hair_pass,
         GPUShader *shader)
 {
-	return drw_shgroup_create_hair_procedural_ex(object, psys, md, hair_pass, NULL, shader);
+	return drw_shgroup_create_particle_hair_procedural_ex(object, psys, md, hair_pass, NULL, shader);
 }
 
-DRWShadingGroup *DRW_shgroup_material_hair_create(
+DRWShadingGroup *DRW_shgroup_material_particle_hair_create(
         Object *object, ParticleSystem *psys, ModifierData *md,
         DRWPass *hair_pass,
         struct GPUMaterial *material)
 {
-	return drw_shgroup_create_hair_procedural_ex(object, psys, md, hair_pass, material, NULL);
+	return drw_shgroup_create_particle_hair_procedural_ex(object, psys, md, hair_pass, material, NULL);
+}
+
+static DRWShadingGroup *drw_shgroup_create_hair_procedural_ex(
+        Object *object, HairSystem *hsys, Mesh *scalp, const HairDrawSettings *draw_set,
+        DRWPass *hair_pass,
+        struct GPUMaterial *gpu_mat, GPUShader *gpu_shader)
+{
+	/* TODO(fclem): Pass the scene as parameter */
+	const DRWContextState *draw_ctx = DRW_context_state_get();
+	Scene *scene = draw_ctx->scene;
+
+	int subdiv = scene->r.hair_subdiv;
+	int thickness_res = (scene->r.hair_type == SCE_HAIR_SHAPE_STRAND) ? 1 : 2;
+
+	ParticleHairCache *hair_cache;
+	bool need_ft_update = hair_ensure_procedural_data(object, hsys, scalp, &hair_cache, subdiv, thickness_res);
+
+	DRWShadingGroup *shgrp;
+	if (gpu_mat) {
+		shgrp = DRW_shgroup_material_create(gpu_mat, hair_pass);
+	}
+	else if (gpu_shader) {
+		shgrp = DRW_shgroup_create(gpu_shader, hair_pass);
+	}
+	else {
+		shgrp = NULL;
+		BLI_assert(0);
+	}
+
+	/* TODO optimize this. Only bind the ones GPUMaterial needs. */
+	for (int i = 0; i < hair_cache->num_uv_layers; ++i) {
+		for (int n = 0; hair_cache->uv_layer_names[i][n][0] != '\0'; ++n) {
+			DRW_shgroup_uniform_texture(shgrp, hair_cache->uv_layer_names[i][n], hair_cache->uv_tex[i]);
+		}
+	}
+	for (int i = 0; i < hair_cache->num_col_layers; ++i) {
+		for (int n = 0; hair_cache->col_layer_names[i][n][0] != '\0'; ++n) {
+			DRW_shgroup_uniform_texture(shgrp, hair_cache->col_layer_names[i][n], hair_cache->col_tex[i]);
+		}
+	}
+
+	DRW_shgroup_uniform_texture(shgrp, "hairPointBuffer", hair_cache->final[subdiv].proc_tex);
+	DRW_shgroup_uniform_int_copy(shgrp, "hairThicknessRes", thickness_res);
+	DRW_shgroup_uniform_float(shgrp, "hairRadShape", &draw_set->shape, 1);
+	DRW_shgroup_uniform_float_copy(shgrp, "hairRadRoot", draw_set->root_radius * draw_set->radius_scale * 0.5f);
+	DRW_shgroup_uniform_float_copy(shgrp, "hairRadTip", draw_set->tip_radius * draw_set->radius_scale * 0.5f);
+	DRW_shgroup_uniform_bool_copy(shgrp, "hairCloseTip", (draw_set->shape_flag & PART_SHAPE_CLOSE_TIP) != 0);
+	/* TODO(fclem): Until we have a better way to cull the hair and render with orco, bypass culling test. */
+	DRW_shgroup_call_object_add_no_cull(shgrp, hair_cache->final[subdiv].proc_hairs[thickness_res - 1], object);
+
+	/* Transform Feedback subdiv. */
+	if (need_ft_update) {
+		GPUShader *tf_shader = hair_refine_shader_get(PART_REFINE_CATMULL_ROM);
+		DRWShadingGroup *tf_shgrp = DRW_shgroup_transform_feedback_create(tf_shader, g_tf_pass,
+		                                                                  hair_cache->final[subdiv].proc_point_buf);
+		DRW_shgroup_uniform_texture(tf_shgrp, "hairPointBuffer", hair_cache->point_tex);
+		DRW_shgroup_uniform_texture(tf_shgrp, "hairStrandBuffer", hair_cache->strand_tex);
+		DRW_shgroup_call_procedural_points_add(tf_shgrp, hair_cache->final[subdiv].point_len, NULL);
+	}
+	
+	return shgrp;
+}
+
+DRWShadingGroup *DRW_shgroup_hair_create(
+        Object *object, HairSystem *hsys,
+        Mesh *scalp, const HairDrawSettings *draw_set,
+        DRWPass *hair_pass,
+        GPUShader *shader)
+{
+	return drw_shgroup_create_hair_procedural_ex(object, hsys, scalp, draw_set, hair_pass, NULL, shader);
+}
+
+DRWShadingGroup *DRW_shgroup_material_hair_create(
+        Object *object, HairSystem *hsys,
+        Mesh *scalp, const HairDrawSettings *draw_set,
+        DRWPass *hair_pass,
+        struct GPUMaterial *material)
+{
+	return drw_shgroup_create_hair_procedural_ex(object, hsys, scalp, draw_set, hair_pass, material, NULL);
 }
 
 void DRW_hair_update(void)

source/blender/draw/intern/draw_hair_private.h

@@ -39,16 +39,22 @@ struct Object;
 struct ParticleSystem;
 struct ModifierData;
 struct ParticleHairCache;
+struct HairSystem;
 
 typedef struct ParticleHairFinalCache {
 	/* Output of the subdivision stage: vertex buff sized to subdiv level. */
-	GPUVertBuf *proc_buf;
+	GPUVertBuf *proc_point_buf;
 	GPUTexture *proc_tex;
 
-	 /* Just contains a huge index buffer used to draw the final hair. */
+	GPUVertBuf *proc_hair_index_buf; /* Hair strand index for each vertex */
+	GPUTexture *hair_index_tex;
+
+	/* Just contains a huge index buffer used to draw the final hair. */
 	GPUBatch *proc_hairs[MAX_THICKRES];
 
-	int strands_res; /* points per hair, at least 2 */
+	int strands_len;
+	int elems_len;
+	int point_len;
 } ParticleHairFinalCache;
 
 typedef struct ParticleHairCache {
@@ -81,6 +87,8 @@ typedef struct ParticleHairCache {
 	int point_len;
 } ParticleHairCache;
 
+void particle_batch_cache_clear_hair(struct ParticleHairCache *hair_cache);
+
 bool particles_ensure_procedural_data(
         struct Object *object,
         struct ParticleSystem *psys,
@@ -89,4 +97,12 @@ bool particles_ensure_procedural_data(
         int subdiv,
         int thickness_res);
 
+bool hair_ensure_procedural_data(
+        struct Object *object,
+        struct HairSystem *hsys,
+        struct Mesh *scalp,
+        struct ParticleHairCache **r_hair_cache,
+        int subdiv,
+        int thickness_res);
+
 #endif /* __DRAW_HAIR_PRIVATE_H__ */

source/blender/draw/intern/draw_manager.c

@@ -2464,6 +2464,9 @@ void DRW_engines_register(void)
 		/* BKE: gpencil.c */
 		extern void *BKE_gpencil_batch_cache_dirty_cb;
 		extern void *BKE_gpencil_batch_cache_free_cb;
+		/* BKE: hair.c */
+		extern void *BKE_hair_batch_cache_dirty_cb;
+		extern void *BKE_hair_batch_cache_free_cb;
 
 		BKE_mball_batch_cache_dirty_cb = DRW_mball_batch_cache_dirty;
 		BKE_mball_batch_cache_free_cb = DRW_mball_batch_cache_free;
@@ -2482,6 +2485,9 @@ void DRW_engines_register(void)
 
 		BKE_gpencil_batch_cache_dirty_cb = DRW_gpencil_batch_cache_dirty;
 		BKE_gpencil_batch_cache_free_cb = DRW_gpencil_batch_cache_free;
+
+		BKE_hair_batch_cache_dirty_cb = DRW_hair_batch_cache_dirty;
+		BKE_hair_batch_cache_free_cb = DRW_hair_batch_cache_free;
 	}
 }
 

source/blender/draw/modes/object_mode.c

@@ -114,6 +114,7 @@ typedef struct OBJECT_PassList {
 	struct DRWPass *bone_envelope;
 	struct DRWPass *bone_axes;
 	struct DRWPass *particle;
+	struct DRWPass *hair;
 	struct DRWPass *lightprobes;
 	/* use for empty/background images */
 	struct DRWPass *reference_image;
@@ -247,6 +248,9 @@ typedef struct OBJECT_PrivateData {
 	/* Texture Space */
 	DRWShadingGroup *texspace;
 
+	/* Hair Systems */
+	DRWShadingGroup *hair_verts;
+
 	/* Outlines id offset */
 	int id_ofs_active;
 	int id_ofs_select;
@@ -1350,6 +1354,20 @@ static void OBJECT_cache_init(void *vedata)
 		        DRW_STATE_POINT | DRW_STATE_BLEND);
 	}
 
+	{
+		/* Hair */
+		psl->hair = DRW_pass_create(
+		                "Hair Pass",
+		                DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS | DRW_STATE_BLEND |
+		                DRW_STATE_POINT | DRW_STATE_WIRE);
+
+		GPUShader *sh_verts = GPU_shader_get_builtin_shader(GPU_SHADER_3D_POINT_UNIFORM_SIZE_UNIFORM_COLOR_AA);
+		stl->g_data->hair_verts = DRW_shgroup_create(sh_verts, psl->hair);
+		DRW_shgroup_uniform_vec4(stl->g_data->hair_verts, "color", ts.colorVertex, 1);
+		DRW_shgroup_uniform_float(stl->g_data->hair_verts, "size", &ts.sizeVertex, 1);
+		DRW_shgroup_state_enable(stl->g_data->hair_verts, DRW_STATE_POINT);
+	}
+
 	{
 		/* Empty/Background Image Pass */
 		psl->reference_image = DRW_pass_create(
@@ -2623,6 +2641,7 @@ static void OBJECT_draw_scene(void *vedata)
 		DRW_draw_pass(psl->lightprobes);
 	}
 
+	DRW_draw_pass(psl->hair);
 	DRW_draw_pass(psl->ob_center);
 
 	if (DRW_state_is_fbo()) {

source/blender/draw/modes/shaders/common_hair_lib.glsl

@@ -5,13 +5,6 @@
  * of data the CPU has to precompute and transfert for each update.
  **/
 
-/**
- * hairStrandsRes: Number of points per hair strand.
- * 2 - no subdivision
- * 3+ - 1 or more interpolated points per hair.
- **/
-uniform int hairStrandsRes = 8;
-
 /**
  * hairThicknessRes : Subdiv around the hair.
  * 1 - Wire Hair: Only one pixel thick, independant of view distance.
@@ -33,6 +26,7 @@ uniform samplerBuffer hairPointBuffer; /* RGBA32F */
 
 /* -- Per strands data -- */
 uniform usamplerBuffer hairStrandBuffer; /* R32UI */
+uniform usamplerBuffer hairIndexBuffer; /* R32UI */
 
 /* Not used, use one buffer per uv layer */
 //uniform samplerBuffer hairUVBuffer; /* RG32F */
@@ -49,6 +43,13 @@ void unpack_strand_data(uint data, out int strand_offset, out int strand_segment
 #endif
 }
 
+int hair_get_strand_id(void)
+{
+	//return gl_VertexID / (hairStrandsRes * hairThicknessRes);
+	uint strand_index = texelFetch(hairIndexBuffer, gl_VertexID).x;
+	return int(strand_index);
+}
+
 /* -- Subdivision stage -- */
 /**
  * We use a transform feedback to preprocess the strands and add more subdivision to it.
@@ -59,40 +60,40 @@ void unpack_strand_data(uint data, out int strand_offset, out int strand_segment
  **/
 
 #ifdef HAIR_PHASE_SUBDIV
-int hair_get_base_id(float local_time, int strand_segments, out float interp_time)
+/**
+ * Calculate segment and local time for interpolation
+ */
+void hair_get_interp_time(float local_time, int strand_segments, out int interp_segment, out float interp_time)
 {
 	float time_per_strand_seg = 1.0 / float(strand_segments);
 
 	float ratio = local_time / time_per_strand_seg;
+	interp_segment = int(ratio);
 	interp_time = fract(ratio);
-
-	return int(ratio);
 }
 
 void hair_get_interp_attribs(out vec4 data0, out vec4 data1, out vec4 data2, out vec4 data3, out float interp_time)
 {
-	float local_time = float(gl_VertexID % hairStrandsRes) / float(hairStrandsRes - 1);
-
-	int hair_id = gl_VertexID / hairStrandsRes;
-	uint strand_data = texelFetch(hairStrandBuffer, hair_id).x;
-
+	int strand_index = hair_get_strand_id();
+	uint strand_data = texelFetch(hairStrandBuffer, strand_index).x;
 	int strand_offset, strand_segments;
 	unpack_strand_data(strand_data, strand_offset, strand_segments);
 
-	int id = hair_get_base_id(local_time, strand_segments, interp_time);
+	float local_time = float(gl_VertexID - strand_offset) / float(strand_segments);
+	int interp_segment;
+	hair_get_interp_time(local_time, strand_segments, interp_segment, interp_time);
+	int interp_point = interp_segment + strand_offset;
 
-	int ofs_id = id + strand_offset;
+	data0 = texelFetch(hairPointBuffer, interp_point - 1);
+	data1 = texelFetch(hairPointBuffer, interp_point);
+	data2 = texelFetch(hairPointBuffer, interp_point + 1);
+	data3 = texelFetch(hairPointBuffer, interp_point + 2);
 
-	data0 = texelFetch(hairPointBuffer, ofs_id - 1);
-	data1 = texelFetch(hairPointBuffer, ofs_id);
-	data2 = texelFetch(hairPointBuffer, ofs_id + 1);
-	data3 = texelFetch(hairPointBuffer, ofs_id + 2);
-
-	if (id <= 0) {
+	if (interp_segment <= 0) {
 		/* root points. Need to reconstruct previous data. */
 		data0 = data1 * 2.0 - data2;
 	}
-	if (id + 1 >= strand_segments) {
+	if (interp_segment + 1 >= strand_segments) {
 		/* tip points. Need to reconstruct next data. */
 		data3 = data2 * 2.0 - data1;
 	}
@@ -105,11 +106,6 @@ void hair_get_interp_attribs(out vec4 data0, out vec4 data1, out vec4 data2, out
  **/
 
 #ifndef HAIR_PHASE_SUBDIV
-int hair_get_strand_id(void)
-{
-	return gl_VertexID / (hairStrandsRes * hairThicknessRes);
-}
-
 int hair_get_base_id(void)
 {
 	return gl_VertexID / hairThicknessRes;
@@ -165,25 +161,25 @@ void hair_get_pos_tan_binor_time(
 
 vec2 hair_get_customdata_vec2(const samplerBuffer cd_buf)
 {
-	int id = hair_get_strand_id();
-	return texelFetch(cd_buf, id).rg;
+	int strand_index = hair_get_strand_id();
+	return texelFetch(cd_buf, strand_index).rg;
 }
 
 vec3 hair_get_customdata_vec3(const samplerBuffer cd_buf)
 {
-	int id = hair_get_strand_id();
-	return texelFetch(cd_buf, id).rgb;
+	int strand_index = hair_get_strand_id();
+	return texelFetch(cd_buf, strand_index).rgb;
 }
 
 vec4 hair_get_customdata_vec4(const samplerBuffer cd_buf)
 {
-	int id = hair_get_strand_id();
-	return texelFetch(cd_buf, id).rgba;
+	int strand_index = hair_get_strand_id();
+	return texelFetch(cd_buf, strand_index).rgba;
 }
 
-vec3 hair_get_strand_pos(void)
+vec3 hair_get_strand_pos()
 {
-	int id = hair_get_strand_id() * hairStrandsRes;
+	int id = hair_get_base_id();
 	return texelFetch(hairPointBuffer, id).point_position;
 }
 

source/blender/editors/object/object_intern.h

@@ -175,6 +175,7 @@ void OBJECT_OT_skin_radii_equalize(struct wmOperatorType *ot);
 void OBJECT_OT_skin_armature_create(struct wmOperatorType *ot);
 void OBJECT_OT_laplaciandeform_bind(struct wmOperatorType *ot);
 void OBJECT_OT_surfacedeform_bind(struct wmOperatorType *ot);
+void OBJECT_OT_hair_generate_follicles(struct wmOperatorType *ot);
 
 /* grease pencil modifiers */
 void OBJECT_OT_gpencil_modifier_add(struct wmOperatorType *ot);

source/blender/editors/object/object_modifier.c

@@ -37,6 +37,7 @@
 #include "DNA_anim_types.h"
 #include "DNA_armature_types.h"
 #include "DNA_curve_types.h"
+#include "DNA_hair_types.h"
 #include "DNA_key_types.h"
 #include "DNA_mesh_types.h"
 #include "DNA_meshdata_types.h"
@@ -58,12 +59,14 @@
 #include "BKE_DerivedMesh.h"
 #include "BKE_effect.h"
 #include "BKE_global.h"
+#include "BKE_hair.h"
 #include "BKE_key.h"
 #include "BKE_lattice.h"
 #include "BKE_main.h"
 #include "BKE_mesh.h"
 #include "BKE_mesh_mapping.h"
 #include "BKE_mesh_runtime.h"
+#include "BKE_mesh_sample.h"
 #include "BKE_modifier.h"
 #include "BKE_multires.h"
 #include "BKE_report.h"
@@ -2417,3 +2420,88 @@ void OBJECT_OT_surfacedeform_bind(wmOperatorType *ot)
 	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
 	edit_modifier_properties(ot);
 }
+
+/************************ Hair follicle generate operator *********************/
+
+static int hair_generate_follicles_poll(bContext *C)
+{
+	return edit_modifier_poll_generic(C, &RNA_HairModifier, 0);
+}
+
+static int hair_generate_follicles_exec(bContext *C, wmOperator *op)
+{
+	Object *ob = ED_object_active_context(C);
+	HairModifierData *hmd = (HairModifierData *)edit_modifier_property_get(op, ob, eModifierType_Hair);
+
+	if (!hmd)
+		return OPERATOR_CANCELLED;
+
+	BLI_assert(hmd->hair_system != NULL);
+	
+	struct Depsgraph *depsgraph = CTX_data_depsgraph(C);
+	
+	BLI_assert(ob && ob->type == OB_MESH);
+	Mesh *scalp = (Mesh *)DEG_get_evaluated_id(depsgraph, ob->data);
+	HairSystem *hsys = hmd->hair_system;
+	
+	BKE_hair_generate_follicles(
+	            hsys,
+	            scalp,
+	            (unsigned int)hmd->follicle_seed,
+	            hmd->follicle_count);
+	
+	{
+		const int numverts = 5;
+		const float hairlen = 0.05f;
+		const float taper_length = 0.02f;
+		const float taper_thickness = 0.8f;
+		BKE_hair_fiber_curves_begin(hsys, hsys->pattern->num_follicles);
+		for (int i = 0; i < hsys->pattern->num_follicles; ++i)
+		{
+			BKE_hair_set_fiber_curve(hsys, i, numverts, taper_length, taper_thickness);
+		}
+		BKE_hair_fiber_curves_end(hsys);
+		for (int i = 0; i < hsys->pattern->num_follicles; ++i)
+		{
+			float loc[3], nor[3], tan[3];
+			BKE_mesh_sample_eval(scalp, &hsys->pattern->follicles[i].mesh_sample, loc, nor, tan);
+			for (int j = 0; j < numverts; ++j)
+			{
+				madd_v3_v3fl(loc, nor, hairlen / (numverts-1));
+				BKE_hair_set_fiber_vertex(hsys, i * numverts + j, 0, loc);
+			}
+		}
+	}
+	
+	BKE_hair_bind_follicles(hmd->hair_system, scalp);
+	
+	DEG_id_tag_update(&ob->id, OB_RECALC_DATA);
+	WM_event_add_notifier(C, NC_OBJECT | ND_MODIFIER, ob);
+	
+	return OPERATOR_FINISHED;
+}
+
+static int hair_generate_follicles_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
+{
+	if (edit_modifier_invoke_properties(C, op))
+		return hair_generate_follicles_exec(C, op);
+	else
+		return OPERATOR_CANCELLED;
+}
+
+void OBJECT_OT_hair_generate_follicles(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name = "Hair Follicles Generate";
+	ot->description = "Generate hair follicles for a hair modifier";
+	ot->idname = "OBJECT_OT_hair_generate_follicles";
+
+	/* api callbacks */
+	ot->poll = hair_generate_follicles_poll;
+	ot->invoke = hair_generate_follicles_invoke;
+	ot->exec = hair_generate_follicles_exec;
+
+	/* flags */
+	ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
+	edit_modifier_properties(ot);
+}

source/blender/editors/object/object_ops.c

@@ -263,6 +263,7 @@ void ED_operatortypes_object(void)
 	WM_operatortype_append(OBJECT_OT_data_transfer);
 	WM_operatortype_append(OBJECT_OT_datalayout_transfer);
 	WM_operatortype_append(OBJECT_OT_surfacedeform_bind);
+	WM_operatortype_append(OBJECT_OT_hair_generate_follicles);
 
 	WM_operatortype_append(OBJECT_OT_hide_view_clear);
 	WM_operatortype_append(OBJECT_OT_hide_view_set);

source/blender/editors/space_outliner/outliner_draw.c

@@ -1039,6 +1039,9 @@ TreeElementIcon tree_element_get_icon(TreeStoreElem *tselem, TreeElement *te)
 						case eModifierType_WeightedNormal:
 							data.icon = ICON_MOD_NORMALEDIT;
 							break;
+						case eModifierType_Hair:
+							data.icon = ICON_STRANDS;
+							break;
 							/* Default */
 						case eModifierType_None:
 						case eModifierType_ShapeKey:

source/blender/gpu/GPU_texture.h

@@ -107,10 +107,10 @@ typedef enum GPUTextureFormat {
 
 	/* Texture only format */
 	GPU_RGB16F,
+	GPU_RGB32F,
 #if 0
 	GPU_RGBA16_SNORM,
 	GPU_RGBA8_SNORM,
-	GPU_RGB32F,
 	GPU_RGB32I,
 	GPU_RGB32UI,
 	GPU_RGB16_SNORM,

source/blender/makesdna/DNA_hair_types.h

@@ -0,0 +1,136 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software  Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Contributor(s): Blender Foundation
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ *
+ */
+
+/** \file DNA_hair_types.h
+ *  \ingroup DNA
+ */
+
+#ifndef __DNA_HAIR_TYPES_H__
+#define __DNA_HAIR_TYPES_H__
+
+#include "DNA_defs.h"
+#include "DNA_listBase.h"
+#include "DNA_ID.h"
+#include "DNA_meshdata_types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Root point (follicle) of a hair on a surface */
+typedef struct HairFollicle {
+	MeshSample mesh_sample;     /* Sample on the scalp mesh for the root vertex */
+	unsigned int curve;         /* Index of the curve used by the fiber */
+	int pad;
+} HairFollicle;
+
+/* Collection of hair roots on a surface */
+typedef struct HairPattern {
+	struct HairFollicle *follicles;
+	int num_follicles;
+	int pad;
+} HairPattern;
+
+typedef struct HairFiberCurve {
+	int vertstart;                      /* Offset in the vertex array where the curve starts */
+	int numverts;                       /* Number of vertices in the curve */
+
+	/* Shape */
+	float taper_length;                 /* Distance at which final thickness is reached */
+	float taper_thickness;              /* Relative thickness of the strand */
+} HairFiberCurve;
+
+typedef struct HairFiberVertex {
+	int flag;
+	float co[3];
+} HairFiberVertex;
+
+/* Hair curve data */
+typedef struct HairCurveData
+{
+	/* Curves for shaping hair fibers */
+	struct HairFiberCurve *curves;
+	/* Control vertices on curves */
+	struct HairFiberVertex *verts;
+	/* Number of curves */
+	int totcurves;
+	/* Number of curve vertices */
+	int totverts;
+} HairCurveData;
+
+typedef struct HairSystem {
+	int flag;
+	int pad;
+	
+	/* Set of hair follicles on the scalp mesh */
+	struct HairPattern *pattern;
+	
+	/* Curve data */
+	HairCurveData curve_data;
+	
+	/* Data buffers for drawing */
+	void *draw_batch_cache;
+	/* Texture buffer for drawing */
+	void *draw_texture_cache;
+} HairSystem;
+
+typedef enum eHairSystemFlag
+{
+	/* Curve positions have changed, rebind hair follicles */
+	HAIR_SYSTEM_UPDATE_FOLLICLE_BINDING = (1 << 8),
+} eHairSystemFlag;
+
+typedef struct HairDrawSettings
+{
+	short follicle_mode;
+	short fiber_mode;
+	short shape_flag;
+	short pad;
+	
+	float shape;
+	float root_radius;
+	float tip_radius;
+	float radius_scale;
+} HairDrawSettings;
+
+typedef enum eHairDrawFollicleMode
+{
+	HAIR_DRAW_FOLLICLE_NONE     = 0,
+	HAIR_DRAW_FOLLICLE_POINTS   = 1,
+} eHairDrawFollicleMode;
+
+typedef enum eHairDrawFiberMode
+{
+	HAIR_DRAW_FIBER_NONE        = 0,
+	HAIR_DRAW_FIBER_CURVES      = 1,
+} eHairDrawFiberMode;
+
+typedef enum eHairDrawShapeFlag {
+	HAIR_DRAW_CLOSE_TIP         = (1<<0),
+} eHairDrawShapeFlag;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __DNA_HAIR_TYPES_H__ */

source/blender/makesdna/DNA_meshdata_types.h

@@ -380,6 +380,13 @@ enum {
 	FREESTYLE_FACE_MARK = 1,
 };
 
+typedef struct MeshSample {
+	unsigned int orig_verts[3];
+	float orig_weights[3]; /* also used as volume sample location */
+	unsigned int orig_poly;
+	unsigned int orig_loops[3];
+} MeshSample;
+
 /* mvert->flag */
 enum {
 /*	SELECT              = (1 << 0), */

source/blender/makesdna/DNA_modifier_types.h

@@ -91,6 +91,7 @@ typedef enum ModifierType {
 	eModifierType_MeshSequenceCache = 52,
 	eModifierType_SurfaceDeform     = 53,
 	eModifierType_WeightedNormal	= 54,
+	eModifierType_Hair              = 55,
 	NUM_MODIFIER_TYPES
 } ModifierType;
 
@@ -1692,4 +1693,32 @@ enum {
 #define MOD_MESHSEQ_READ_ALL \
 	(MOD_MESHSEQ_READ_VERT | MOD_MESHSEQ_READ_POLY | MOD_MESHSEQ_READ_UV | MOD_MESHSEQ_READ_COLOR)
 
+/* Hair modifier */
+typedef struct HairModifierFiberCurve {
+	struct HairModifierFiberCurve *next, *prev;
+	
+	/* Index for the mesh sample buffer */
+	int mesh_sample_index;
+	/* Number of vertices in the curve */
+	int numverts;
+	/* Vertex array */
+	struct HairFiberVertex *verts;
+} HairModifierFiberCurve;
+
+typedef struct HairModifierData {
+	ModifierData modifier;
+	
+	int flag;
+	int pad;
+	
+	struct HairSystem *hair_system;
+	struct HairDrawSettings *draw_settings;
+	
+	/* Follicle distribution parameters */
+	int follicle_seed;
+	int follicle_count;
+
+	ListBase fiber_curves;
+} HairModifierData;
+
 #endif  /* __DNA_MODIFIER_TYPES_H__ */

source/blender/makesdna/intern/makesdna.c

@@ -131,6 +131,7 @@ static const char *includefiles[] = {
 	"DNA_layer_types.h",
 	"DNA_workspace_types.h",
 	"DNA_lightprobe_types.h",
+	"DNA_hair_types.h",
 
 	/* see comment above before editing! */
 
@@ -1357,5 +1358,6 @@ int main(int argc, char **argv)
 #include "DNA_layer_types.h"
 #include "DNA_workspace_types.h"
 #include "DNA_lightprobe_types.h"
+#include "DNA_hair_types.h"
 
 /* end of list */

source/blender/makesrna/RNA_access.h

@@ -277,6 +277,9 @@ extern StructRNA RNA_GPencilSculptBrush;
 extern StructRNA RNA_GaussianBlurSequence;
 extern StructRNA RNA_GlowSequence;
 extern StructRNA RNA_GreasePencil;
+extern StructRNA RNA_HairGroup;
+extern StructRNA RNA_HairModifier;
+extern StructRNA RNA_HairPattern;
 extern StructRNA RNA_Header;
 extern StructRNA RNA_HemiLight;
 extern StructRNA RNA_Histogram;

source/blender/makesrna/intern/CMakeLists.txt

@@ -52,6 +52,7 @@ set(DEFSRC
 	rna_gpencil_modifier.c
 	rna_shader_fx.c
 	rna_group.c
+	rna_hair.c
 	rna_image.c
 	rna_key.c
 	rna_lamp.c
@@ -62,6 +63,7 @@ set(DEFSRC
 	rna_mask.c
 	rna_material.c
 	rna_mesh.c
+	rna_mesh_sample.c
 	rna_meta.c
 	rna_modifier.c
 	rna_movieclip.c

source/blender/makesrna/intern/makesrna.c

@@ -3405,6 +3405,7 @@ static RNAProcessItem PROCESS_ITEMS[] = {
 	{"rna_fluidsim.c", NULL, RNA_def_fluidsim},
 	{"rna_gpencil.c", NULL, RNA_def_gpencil},
 	{"rna_group.c", NULL, RNA_def_collections},
+	{"rna_hair.c", NULL, RNA_def_hair},
 	{"rna_image.c", "rna_image_api.c", RNA_def_image},
 	{"rna_key.c", NULL, RNA_def_key},
 	{"rna_lamp.c", NULL, RNA_def_light},
@@ -3414,6 +3415,7 @@ static RNAProcessItem PROCESS_ITEMS[] = {
 	{"rna_main.c", "rna_main_api.c", RNA_def_main},
 	{"rna_material.c", "rna_material_api.c", RNA_def_material},
 	{"rna_mesh.c", "rna_mesh_api.c", RNA_def_mesh},
+	{"rna_mesh_sample.c", NULL, RNA_def_mesh_sample},
 	{"rna_meta.c", "rna_meta_api.c", RNA_def_meta},
 	{"rna_modifier.c", NULL, RNA_def_modifier},
 	{"rna_gpencil_modifier.c", NULL, RNA_def_greasepencil_modifier},

source/blender/makesrna/intern/rna_hair.c

@@ -0,0 +1,222 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * Contributor(s): Blender Foundation.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/makesrna/intern/rna_hair.c
+ *  \ingroup RNA
+ */
+
+#include <stdlib.h>
+
+#include "RNA_define.h"
+#include "RNA_enum_types.h"
+
+#include "rna_internal.h"
+
+#include "DNA_hair_types.h"
+
+#include "WM_types.h"
+
+#ifdef RNA_RUNTIME
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_listbase.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_object_types.h"
+
+#include "BKE_context.h"
+#include "BKE_hair.h"
+#include "BKE_main.h"
+
+#include "DEG_depsgraph.h"
+#include "DEG_depsgraph_query.h"
+
+#include "RNA_access.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
+
+static void UNUSED_FUNCTION(rna_HairSystem_update)(Main *UNUSED(bmain), Scene *UNUSED(scene), PointerRNA *ptr)
+{
+	DEG_id_tag_update(ptr->id.data, OB_RECALC_DATA);
+}
+
+static void rna_HairDrawSettings_update(Main *UNUSED(bmain), Scene *UNUSED(scene), PointerRNA *ptr)
+{
+#if 0
+	/* XXX Only need to update render engines
+	 * However, that requires finding all hair systems using these draw settings,
+	 * then flagging the cache as dirty.
+	 */
+	BKE_hair_batch_cache_dirty(hsys, BKE_HAIR_BATCH_DIRTY_ALL);
+#else
+	DEG_id_tag_update(ptr->id.data, OB_RECALC_DATA);
+#endif
+	WM_main_add_notifier(NC_OBJECT | ND_DRAW, ptr->id.data);
+}
+
+static void rna_HairSystem_generate_follicles(
+        HairSystem *hsys,
+        struct bContext *C,
+        Object *scalp,
+        int seed,
+        int count)
+{
+	if (!scalp)
+	{
+		return;
+	}
+	
+	struct Depsgraph *depsgraph = CTX_data_depsgraph(C);
+	
+	BLI_assert(scalp && scalp->type == OB_MESH);
+	Mesh *scalp_mesh = (Mesh *)DEG_get_evaluated_id(depsgraph, scalp->data);
+	
+	BKE_hair_generate_follicles(hsys, scalp_mesh, (unsigned int)seed, count);
+}
+
+#else
+
+static void rna_def_hair_follicle(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+	
+	srna = RNA_def_struct(brna, "HairFollicle", NULL);
+	RNA_def_struct_ui_text(srna, "Hair Follicle", "Single follicle on a surface");
+	RNA_def_struct_sdna(srna, "HairFollicle");
+	
+	prop = RNA_def_property(srna, "mesh_sample", PROP_POINTER, PROP_NONE);
+	RNA_def_property_struct_type(prop, "MeshSample");
+}
+
+static void rna_def_hair_pattern(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+	
+	srna = RNA_def_struct(brna, "HairPattern", NULL);
+	RNA_def_struct_ui_text(srna, "Hair Pattern", "Set of hair follicles distributed on a surface");
+	RNA_def_struct_sdna(srna, "HairPattern");
+	RNA_def_struct_ui_icon(srna, ICON_STRANDS);
+	
+	prop = RNA_def_property(srna, "follicles", PROP_COLLECTION, PROP_NONE);
+	RNA_def_property_collection_sdna(prop, NULL, "follicles", "num_follicles");
+	RNA_def_property_struct_type(prop, "HairFollicle");
+	RNA_def_property_ui_text(prop, "Follicles", "Hair fiber follicles");
+}
+
+static void rna_def_hair_system(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	FunctionRNA *func;
+	PropertyRNA *prop, *parm;
+	
+	srna = RNA_def_struct(brna, "HairSystem", NULL);
+	RNA_def_struct_ui_text(srna, "Hair System", "Hair rendering and deformation data");
+	RNA_def_struct_sdna(srna, "HairSystem");
+	RNA_def_struct_ui_icon(srna, ICON_STRANDS);
+	
+	prop = RNA_def_property(srna, "pattern", PROP_POINTER, PROP_NONE);
+	RNA_def_property_struct_type(prop, "HairPattern");
+	RNA_def_property_ui_text(prop, "Pattern", "Hair pattern");
+	
+	func = RNA_def_function(srna, "generate_follicles", "rna_HairSystem_generate_follicles");
+	RNA_def_function_flag(func, FUNC_USE_CONTEXT);
+	parm = RNA_def_pointer(func, "scalp", "Object", "Scalp", "Scalp object on which to place hair follicles");
+	RNA_def_parameter_flags(parm, 0, PARM_REQUIRED);
+	parm = RNA_def_int(func, "seed", 0, 0, INT_MAX, "Seed", "Seed value for random numbers", 0, INT_MAX);
+	parm = RNA_def_int(func, "count", 0, 0, INT_MAX, "Count", "Maximum number of follicles to generate", 1, 1e5);
+	RNA_def_parameter_flags(parm, 0, PARM_REQUIRED);
+}
+
+static void rna_def_hair_draw_settings(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+	
+	static const EnumPropertyItem follicle_mode_items[] = {
+	    {HAIR_DRAW_FOLLICLE_NONE, "NONE", 0, "None", ""},
+	    {HAIR_DRAW_FOLLICLE_POINTS, "POINTS", 0, "Points", "Draw a point for each follicle"},
+	    {0, NULL, 0, NULL, NULL}
+	};
+	
+	static const EnumPropertyItem fiber_mode_items[] = {
+	    {HAIR_DRAW_FIBER_NONE, "NONE", 0, "None", ""},
+	    {HAIR_DRAW_FIBER_CURVES, "CURVES", 0, "Curves", "Draw fiber curves"},
+	    {0, NULL, 0, NULL, NULL}
+	};
+	
+	srna = RNA_def_struct(brna, "HairDrawSettings", NULL);
+	RNA_def_struct_ui_text(srna, "Hair Draw Settings", "Settings for drawing hair systems");
+	RNA_def_struct_sdna(srna, "HairDrawSettings");
+	
+	prop = RNA_def_property(srna, "follicle_mode", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_items(prop, follicle_mode_items);
+	RNA_def_property_ui_text(prop, "Follicle Mode", "Draw follicles on the scalp surface");
+	RNA_def_property_update(prop, 0, "rna_HairDrawSettings_update");
+	
+	prop = RNA_def_property(srna, "fiber_mode", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_items(prop, fiber_mode_items);
+	RNA_def_property_ui_text(prop, "Fiber Mode", "Draw fiber curves");
+	RNA_def_property_update(prop, 0, "rna_HairDrawSettings_update");
+	
+	/* hair shape */
+	prop = RNA_def_property(srna, "use_close_tip", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "shape_flag", HAIR_DRAW_CLOSE_TIP);
+	RNA_def_property_ui_text(prop, "Close Tip", "Set tip radius to zero");
+	RNA_def_property_update(prop, 0, "rna_HairDrawSettings_update");
+
+	prop = RNA_def_property(srna, "shape", PROP_FLOAT, PROP_FACTOR);
+	RNA_def_property_range(prop, -1.0f, 1.0f);
+	RNA_def_property_ui_text(prop, "Shape", "Strand shape parameter");
+	RNA_def_property_update(prop, 0, "rna_HairDrawSettings_update");
+
+	prop = RNA_def_property(srna, "root_radius", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_range(prop, 0.0f, FLT_MAX);
+	RNA_def_property_ui_range(prop, 0.0f, 10.0f, 0.1, 2);
+	RNA_def_property_ui_text(prop, "Root", "Strand width at the root");
+	RNA_def_property_update(prop, 0, "rna_HairDrawSettings_update");
+
+	prop = RNA_def_property(srna, "tip_radius", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_range(prop, 0.0f, FLT_MAX);
+	RNA_def_property_ui_range(prop, 0.0f, 10.0f, 0.1, 2);
+	RNA_def_property_ui_text(prop, "Tip", "Strand width at the tip");
+	RNA_def_property_update(prop, 0, "rna_HairDrawSettings_update");
+
+	prop = RNA_def_property(srna, "radius_scale", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_range(prop, 0.0f, FLT_MAX);
+	RNA_def_property_ui_range(prop, 0.0f, 10.0f, 0.1, 2);
+	RNA_def_property_ui_text(prop, "Scaling", "Multiplier of radius properties");
+	RNA_def_property_update(prop, 0, "rna_HairDrawSettings_update");
+}
+
+void RNA_def_hair(BlenderRNA *brna)
+{
+	rna_def_hair_follicle(brna);
+	rna_def_hair_pattern(brna);
+	rna_def_hair_system(brna);
+	rna_def_hair_draw_settings(brna);
+}
+
+#endif

source/blender/makesrna/intern/rna_internal.h

@@ -163,6 +163,7 @@ void RNA_def_linestyle(struct BlenderRNA *brna);
 void RNA_def_main(struct BlenderRNA *brna);
 void RNA_def_material(struct BlenderRNA *brna);
 void RNA_def_mesh(struct BlenderRNA *brna);
+void RNA_def_mesh_sample(struct BlenderRNA *brna);
 void RNA_def_meta(struct BlenderRNA *brna);
 void RNA_def_modifier(struct BlenderRNA *brna);
 void RNA_def_nla(struct BlenderRNA *brna);
@@ -201,6 +202,7 @@ void RNA_def_world(struct BlenderRNA *brna);
 void RNA_def_movieclip(struct BlenderRNA *brna);
 void RNA_def_tracking(struct BlenderRNA *brna);
 void RNA_def_mask(struct BlenderRNA *brna);
+void RNA_def_hair(struct BlenderRNA *brna);
 
 /* Common Define functions */
 

source/blender/makesrna/intern/rna_mesh_sample.c

@@ -0,0 +1,73 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/makesrna/intern/rna_mesh_sample.c
+ *  \ingroup RNA
+ */
+
+#include <stdlib.h>
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_meshdata_types.h"
+
+#include "BLI_utildefines.h"
+
+#include "BKE_mesh_sample.h"
+
+#include "RNA_access.h"
+#include "RNA_define.h"
+#include "RNA_types.h"
+
+#include "rna_internal.h"
+
+#include "WM_types.h"
+
+
+#ifdef RNA_RUNTIME
+
+#include "WM_api.h"
+#include "WM_types.h"
+
+
+
+#else
+
+static void rna_def_mesh_sample(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+
+	srna = RNA_def_struct(brna, "MeshSample", NULL);
+	RNA_def_struct_sdna(srna, "MeshSample");
+	RNA_def_struct_ui_text(srna, "Mesh Sample", "Point on a mesh that follows deformation");
+
+	prop = RNA_def_property(srna, "vertex_indices", PROP_INT, PROP_UNSIGNED);
+	RNA_def_property_int_sdna(prop, NULL, "orig_verts");
+	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
+	RNA_def_property_ui_text(prop, "Vertex Indices", "Index of the mesh vertices used for interpolation");
+}
+
+void RNA_def_mesh_sample(BlenderRNA *brna)
+{
+	rna_def_mesh_sample(brna);
+}
+
+#endif

source/blender/makesrna/intern/rna_modifier.c

@@ -115,6 +115,7 @@ const EnumPropertyItem rna_enum_object_modifier_type_items[] = {
 	{eModifierType_DynamicPaint, "DYNAMIC_PAINT", ICON_MOD_DYNAMICPAINT, "Dynamic Paint", ""},
 	{eModifierType_Explode, "EXPLODE", ICON_MOD_EXPLODE, "Explode", ""},
 	{eModifierType_Fluidsim, "FLUID_SIMULATION", ICON_MOD_FLUIDSIM, "Fluid Simulation", ""},
+	{eModifierType_Hair, "HAIR", ICON_STRANDS, "Hair", ""},
 	{eModifierType_Ocean, "OCEAN", ICON_MOD_OCEAN, "Ocean", ""},
 	{eModifierType_ParticleInstance, "PARTICLE_INSTANCE", ICON_MOD_PARTICLES, "Particle Instance", ""},
 	{eModifierType_ParticleSystem, "PARTICLE_SYSTEM", ICON_MOD_PARTICLES, "Particle System", ""},
@@ -281,12 +282,17 @@ const EnumPropertyItem rna_enum_axis_flag_xyz_items[] = {
 
 #ifdef RNA_RUNTIME
 
+#include "BLI_listbase.h"
+
 #include "DNA_particle_types.h"
 #include "DNA_curve_types.h"
 #include "DNA_smoke_types.h"
+#include "DNA_hair_types.h"
+#include "DNA_meshdata_types.h"
 
 #include "BKE_cachefile.h"
 #include "BKE_context.h"
+#include "BKE_hair.h"
 #include "BKE_library.h"
 #include "BKE_mesh_runtime.h"
 #include "BKE_modifier.h"
@@ -295,6 +301,7 @@ const EnumPropertyItem rna_enum_axis_flag_xyz_items[] = {
 
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_build.h"
+#include "DEG_depsgraph_query.h"
 
 #ifdef WITH_ALEMBIC
 #  include "ABC_alembic.h"
@@ -417,6 +424,8 @@ static StructRNA *rna_Modifier_refine(struct PointerRNA *ptr)
 			return &RNA_SurfaceDeformModifier;
 		case eModifierType_WeightedNormal:
 			return &RNA_WeightedNormalModifier;
+		case eModifierType_Hair:
+			return &RNA_HairModifier;
 		/* Default */
 		case eModifierType_None:
 		case eModifierType_ShapeKey:
@@ -1174,6 +1183,58 @@ static void rna_ParticleInstanceModifier_particle_system_set(PointerRNA *ptr, co
 	CLAMP_MIN(psmd->psys, 1);
 }
 
+static void rna_Hair_fiber_curves_clear(HairModifierData *hmd)
+{
+	for (HairModifierFiberCurve* curve = hmd->fiber_curves.first; curve; curve = curve->next)
+	{
+		if (curve->verts)
+		{
+			MEM_freeN(curve->verts);
+		}
+	}
+	BLI_freelistN(&hmd->fiber_curves);
+}
+
+static void rna_Hair_fiber_curves_new(HairModifierData *hmd, ReportList *UNUSED(reports), int numverts)
+{
+	HairModifierFiberCurve *curve = MEM_callocN(sizeof(HairModifierFiberCurve), "hair fiber curve");
+	curve->numverts = numverts;
+	curve->verts = MEM_callocN(sizeof(HairFiberVertex) * numverts, "hair fiber curve vertices");
+	
+	BLI_addtail(&hmd->fiber_curves, curve);
+}
+
+static void rna_Hair_fiber_curves_apply(ID *id, HairModifierData *hmd, bContext *C, ReportList *UNUSED(reports))
+{
+	const int totcurves = BLI_listbase_count(&hmd->fiber_curves);
+	int i = 0;
+	
+	BKE_hair_fiber_curves_begin(hmd->hair_system, totcurves);
+	i = 0;
+	for (HairModifierFiberCurve *curve = hmd->fiber_curves.first; curve; curve = curve->next, ++i)
+	{
+		BKE_hair_set_fiber_curve(hmd->hair_system, i, curve->numverts, 0.1, 1.0);
+	}
+	BKE_hair_fiber_curves_end(hmd->hair_system);
+	
+	i = 0;
+	for (HairModifierFiberCurve *curve = hmd->fiber_curves.first; curve; curve = curve->next)
+	{
+		for (int j = 0; j < curve->numverts; ++j, ++i)
+		{
+			BKE_hair_set_fiber_vertex(hmd->hair_system, i, curve->verts[j].flag, curve->verts[j].co);
+		}
+	}
+	
+	{
+		Mesh *scalp = (Mesh *)DEG_get_evaluated_id(CTX_data_depsgraph(C), ((Object*)id)->data);
+		BKE_hair_bind_follicles(hmd->hair_system, scalp);
+	}
+	
+	DEG_id_tag_update(id, OB_RECALC_DATA);
+	WM_main_add_notifier(NC_OBJECT | ND_MODIFIER, id);
+}
+
 #else
 
 static PropertyRNA *rna_def_property_subdivision_common(StructRNA *srna, const char type[])
@@ -4916,6 +4977,52 @@ static void rna_def_modifier_surfacedeform(BlenderRNA *brna)
 	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
 }
 
+static void rna_def_modifier_hair_fiber_curve(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+	
+	srna = RNA_def_struct(brna, "HairModifierFiberCurve", NULL);
+	RNA_def_struct_ui_text(srna, "Hair Modifier Fiber Curve", "");
+	RNA_def_struct_sdna(srna, "HairModifierFiberCurve");
+	
+	prop = RNA_def_property(srna, "vertices", PROP_COLLECTION, PROP_NONE);
+	RNA_def_property_collection_sdna(prop, NULL, "verts", "numverts");
+	RNA_def_property_struct_type(prop, "HairModifierFiberVertex");
+	RNA_def_property_ui_text(prop, "Vertices", "Fiber vertices");
+
+
+	srna = RNA_def_struct(brna, "HairModifierFiberVertex", NULL);
+	RNA_def_struct_ui_text(srna, "Hair Modifier Fiber Vertex", "");
+	RNA_def_struct_sdna(srna, "HairFiberVertex");
+	
+	prop = RNA_def_property(srna, "location", PROP_FLOAT, PROP_TRANSLATION);
+	RNA_def_property_float_sdna(prop, NULL, "co");
+	RNA_def_property_ui_text(prop, "Location", "Location of the vertex relative to the root");
+}
+
+static void rna_def_modifier_hair_fiber_curves_api(BlenderRNA *brna, PropertyRNA *cprop)
+{
+	StructRNA *srna;
+	FunctionRNA *func;
+	PropertyRNA *parm;
+	
+	RNA_def_property_srna(cprop, "HairModifierFiberCurves");
+	srna = RNA_def_struct(brna, "HairModifierFiberCurves", NULL);
+	RNA_def_struct_ui_text(srna, "Hair Modifier Fiber Curves", "");
+	RNA_def_struct_sdna(srna, "HairModifierData");
+	
+	/*func =*/ RNA_def_function(srna, "clear", "rna_Hair_fiber_curves_clear");
+	
+	func = RNA_def_function(srna, "new", "rna_Hair_fiber_curves_new");
+	RNA_def_function_flag(func, FUNC_USE_REPORTS);
+	parm = RNA_def_int(func, "vertex_count", 2, 0, INT_MAX, "Vertex Count", "Number of vertices", 2, 1000);
+	RNA_def_property_flag(parm, PARM_REQUIRED);
+	
+	func = RNA_def_function(srna, "apply", "rna_Hair_fiber_curves_apply");
+	RNA_def_function_flag(func, FUNC_USE_SELF_ID | FUNC_USE_CONTEXT | FUNC_USE_REPORTS);
+}
+
 static void rna_def_modifier_weightednormal(BlenderRNA *brna)
 {
 	StructRNA *srna;
@@ -4978,6 +5085,43 @@ static void rna_def_modifier_weightednormal(BlenderRNA *brna)
 	RNA_def_property_update(prop, 0, "rna_Modifier_update");
 }
 
+static void rna_def_modifier_hair(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+	
+	srna = RNA_def_struct(brna, "HairModifier", "Modifier");
+	RNA_def_struct_ui_text(srna, "Hair Modifier", "");
+	RNA_def_struct_sdna(srna, "HairModifierData");
+	RNA_def_struct_ui_icon(srna, ICON_STRANDS);
+	
+	prop = RNA_def_property(srna, "hair_system", PROP_POINTER, PROP_NONE);
+	RNA_def_property_ui_text(prop, "Hair", "Hair data");
+	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
+	
+	prop = RNA_def_property(srna, "follicle_seed", PROP_INT, PROP_NONE);
+	RNA_def_property_range(prop, 0, INT_MAX);
+	RNA_def_property_ui_text(prop, "Seed", "Follicle distribution random seed value");
+	
+	prop = RNA_def_property(srna, "follicle_count", PROP_INT, PROP_NONE);
+	RNA_def_property_int_default(prop, 100000);
+	RNA_def_property_range(prop, 0, INT_MAX);
+	RNA_def_property_ui_range(prop, 1, 1e5, 1, 1);
+	RNA_def_property_ui_text(prop, "Follicle Count", "Maximum number of follicles");
+	
+	prop = RNA_def_property(srna, "draw_settings", PROP_POINTER, PROP_NONE);
+	RNA_def_property_ui_text(prop, "Draw Settings", "Hair draw settings");
+	RNA_def_property_clear_flag(prop, PROP_EDITABLE);
+
+	prop = RNA_def_property(srna, "fiber_curves", PROP_COLLECTION, PROP_NONE);
+	RNA_def_property_collection_sdna(prop, NULL, "fiber_curves", NULL);
+	RNA_def_property_struct_type(prop, "HairModifierFiberCurve");
+	RNA_def_property_ui_text(prop, "Fiber Curves", "Fiber curve data");
+	rna_def_modifier_hair_fiber_curves_api(brna, prop);
+
+	rna_def_modifier_hair_fiber_curve(brna);
+}
+
 void RNA_def_modifier(BlenderRNA *brna)
 {
 	StructRNA *srna;
@@ -5100,6 +5244,7 @@ void RNA_def_modifier(BlenderRNA *brna)
 	rna_def_modifier_meshseqcache(brna);
 	rna_def_modifier_surfacedeform(brna);
 	rna_def_modifier_weightednormal(brna);
+	rna_def_modifier_hair(brna);
 }
 
 #endif

source/blender/modifiers/CMakeLists.txt

@@ -63,6 +63,7 @@ set(SRC
 	intern/MOD_explode.c
 	intern/MOD_fluidsim.c
 	intern/MOD_fluidsim_util.c
+	intern/MOD_hair.c
 	intern/MOD_hook.c
 	intern/MOD_laplaciandeform.c
 	intern/MOD_laplaciansmooth.c

source/blender/modifiers/MOD_modifiertypes.h

@@ -87,6 +87,7 @@ extern ModifierTypeInfo modifierType_CorrectiveSmooth;
 extern ModifierTypeInfo modifierType_MeshSequenceCache;
 extern ModifierTypeInfo modifierType_SurfaceDeform;
 extern ModifierTypeInfo modifierType_WeightedNormal;
+extern ModifierTypeInfo modifierType_Hair;
 
 /* MOD_util.c */
 void modifier_type_init(ModifierTypeInfo *types[]);

source/blender/modifiers/intern/MOD_hair.c

@@ -0,0 +1,169 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software  Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2005 by the Blender Foundation.
+ * All rights reserved.
+ *
+ * Contributor(s): Daniel Dunbar
+ *                 Ton Roosendaal,
+ *                 Ben Batt,
+ *                 Brecht Van Lommel,
+ *                 Campbell Barton
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ *
+ */
+
+/** \file blender/modifiers/intern/MOD_hair.c
+ *  \ingroup modifiers
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_utildefines.h"
+#include "BLI_listbase.h"
+
+#include "DNA_object_types.h"
+#include "DNA_hair_types.h"
+
+#include "BKE_hair.h"
+#include "BKE_library.h"
+#include "BKE_library_query.h"
+#include "BKE_modifier.h"
+
+#include "DEG_depsgraph_build.h"
+
+#include "MOD_util.h"
+
+
+static void initData(ModifierData *md)
+{
+	HairModifierData *hmd = (HairModifierData *) md;
+	
+	hmd->hair_system = BKE_hair_new();
+	
+	hmd->flag |= 0;
+	
+	hmd->follicle_count = 100000;
+	
+	hmd->draw_settings = BKE_hair_draw_settings_new();
+}
+
+static void copyData(const ModifierData *md, ModifierData *target, const int flag)
+{
+	const HairModifierData *hmd = (HairModifierData *) md;
+	HairModifierData *tfmd = (HairModifierData *) target;
+
+	modifier_copyData_generic(md, target, flag);
+	
+	if (hmd->hair_system) {
+		tfmd->hair_system = BKE_hair_copy(hmd->hair_system);
+	}
+	if (hmd->draw_settings)
+	{
+		tfmd->draw_settings = BKE_hair_draw_settings_copy(hmd->draw_settings);
+	}
+}
+
+static void freeData(ModifierData *md)
+{
+	HairModifierData *hmd = (HairModifierData *) md;
+	
+	if (hmd->hair_system) {
+		BKE_hair_free(hmd->hair_system);
+	}
+	if (hmd->draw_settings)
+	{
+		BKE_hair_draw_settings_free(hmd->draw_settings);
+	}
+	for (HairModifierFiberCurve *curve = hmd->fiber_curves.first; curve; curve = curve->next)
+	{
+		if (curve->verts)
+		{
+			MEM_freeN(curve->verts);
+		}
+	}
+	BLI_freelistN(&hmd->fiber_curves);
+}
+
+static struct Mesh *applyModifier(ModifierData *md, const ModifierEvalContext *ctx,
+                                  struct Mesh *mesh)
+{
+	HairModifierData *hmd = (HairModifierData *) md;
+	
+	UNUSED_VARS(hmd, ctx);
+	
+	return mesh;
+}
+
+static void foreachObjectLink(
+        ModifierData *md,
+        Object *ob,
+        ObjectWalkFunc walk,
+        void *userData)
+{
+	HairModifierData *hmd = (HairModifierData *) md;
+	UNUSED_VARS(ob, walk, userData, hmd);
+}
+
+static void foreachIDLink(
+        ModifierData *md,
+        Object *ob,
+        IDWalkFunc walk,
+        void *userData)
+{
+	HairModifierData *hmd = (HairModifierData *) md;
+	UNUSED_VARS(hmd);
+	
+	foreachObjectLink(md, ob, (ObjectWalkFunc)walk, userData);
+}
+
+ModifierTypeInfo modifierType_Hair = {
+	/* name */              "Hair",
+	/* structName */        "HairModifierData",
+	/* structSize */        sizeof(HairModifierData),
+	/* type */              eModifierTypeType_NonGeometrical,
+	/* flags */             eModifierTypeFlag_AcceptsMesh |
+	                        eModifierTypeFlag_SupportsEditmode,
+
+	/* copyData */          copyData,
+
+	/* deformVerts_DM */    NULL,
+	/* deformMatrices_DM */ NULL,
+	/* deformVertsEM_DM */  NULL,
+	/* deformMatricesEM_DM*/NULL,
+	/* applyModifier_DM */  NULL,
+	/* applyModifierEM_DM */NULL,
+
+	/* deformVerts */       NULL,
+	/* deformMatrices */    NULL,
+	/* deformVertsEM */     NULL,
+	/* deformMatricesEM */  NULL,
+	/* applyModifier */     applyModifier,
+	/* applyModifierEM */   NULL,
+
+	/* initData */          initData,
+	/* requiredDataMask */  NULL,
+	/* freeData */          freeData,
+	/* isDisabled */        NULL,
+	/* updateDepsgraph */   NULL,
+	/* dependsOnTime */     NULL,
+	/* dependsOnNormals */	NULL,
+	/* foreachObjectLink */ foreachObjectLink,
+	/* foreachIDLink */     foreachIDLink,
+	/* foreachTexLink */    NULL,
+};

source/blender/modifiers/intern/MOD_util.c

@@ -291,5 +291,6 @@ void modifier_type_init(ModifierTypeInfo *types[])
 	INIT_TYPE(MeshSequenceCache);
 	INIT_TYPE(SurfaceDeform);
 	INIT_TYPE(WeightedNormal);
+	INIT_TYPE(Hair);
 #undef INIT_TYPE
 }

tests/gtests/CMakeLists.txt

@@ -13,6 +13,7 @@ if(WITH_GTESTS)
 
 	add_subdirectory(testing)
 	add_subdirectory(blenlib)
+	add_subdirectory(blenkernel)
 	add_subdirectory(guardedalloc)
 	add_subdirectory(bmesh)
 	if(WITH_ALEMBIC)

tests/gtests/blenkernel/BKE_mesh_sample_test.cc

@@ -0,0 +1,334 @@
+/* Apache License, Version 2.0 */
+
+#include <iostream>
+#include <fstream>
+#include <sstream>
+
+#include "testing/testing.h"
+
+#include "BKE_mesh_test_util.h"
+
+extern "C" {
+#include "MEM_guardedalloc.h"
+
+#include "BLI_math.h"
+#include "BLI_path_util.h"
+#include "BLI_rand.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+
+#include "BKE_appdir.h"
+#include "BKE_global.h"
+#include "BKE_main.h"
+#include "BKE_mesh.h"
+#include "BKE_mesh_sample.h"
+}
+
+#define TEST_MESH_OUTPUT_FILE "mesh_dump_"
+
+static const float verts[][3] = { {-1, -1, -1}, {1, -1, -1}, {-1, 1, -1}, {1, 1, -1},
+                                  {-1, -1, 1},  {1, -1, 1},  {-1, 1, 1},  {1, 1, 1} };
+static const int faces[] = { 0, 1, 3, 2,
+                             4, 5, 7, 6,
+                             0, 1, 5, 4,
+                             2, 3, 7, 6,
+                             0, 2, 6, 4,
+                             1, 3, 7, 5,
+                           };
+static const int face_lengths[] = { 4, 4, 4, 4, 4, 4 };
+
+class MeshSampleTest : public ::testing::Test
+{
+public:
+	static const unsigned int m_seed;
+	static const int m_numsamples;
+	
+	std::string get_testname() const;
+	
+	void load_mesh(const float (*verts)[3], int numverts,
+	               const int (*edges)[2], int numedges,
+	               const int *faces, const int *face_lengths, int numfaces);
+	void load_mesh(const char *filename);
+	void unload_mesh();
+	
+	void generate_samples_simple(struct MeshSampleGenerator *gen);
+	void generate_samples_batch(struct MeshSampleGenerator *gen);
+	void generate_samples_batch_threaded(struct MeshSampleGenerator *gen);
+	void compare_samples(const struct MeshSample *ground_truth);
+	void test_samples(struct MeshSampleGenerator *gen, const struct MeshSample *ground_truth, int count);
+	
+	void dump_samples();
+	
+protected:
+	void SetUp() override;
+	void TearDown() override;
+	
+protected:
+	Mesh *m_mesh;
+	
+	MeshSample *m_samples;
+};
+
+const unsigned int MeshSampleTest::m_seed = 8343;
+const int MeshSampleTest::m_numsamples = 100000;
+
+std::string MeshSampleTest::get_testname() const
+{
+	std::stringstream testname;
+	testname << ::testing::UnitTest::GetInstance()->current_test_info()->name();
+	return testname.str();
+}
+
+void MeshSampleTest::load_mesh(const float (*verts)[3], int numverts,
+                               const int (*edges)[2], int numedges,
+                               const int *faces, const int *face_lengths, int numfaces)
+{
+	m_mesh = BKE_mesh_test_from_data(verts, numverts, edges, numedges, faces, face_lengths, numfaces);
+}
+
+void MeshSampleTest::load_mesh(const char *filename)
+{
+	const char *folder = BKE_appdir_folder_id(BLENDER_DATAFILES, "tests");
+	char path[FILE_MAX];
+
+	BLI_make_file_string(G.main->name, path, folder, filename);
+
+	if (path[0]) {
+		m_mesh = BKE_mesh_test_from_csv(path);
+	}
+}
+
+void MeshSampleTest::unload_mesh()
+{
+	if (m_mesh) {
+		BKE_mesh_free(m_mesh);
+		MEM_freeN(m_mesh);
+		m_mesh = NULL;
+	}
+}
+
+void MeshSampleTest::SetUp()
+{
+	load_mesh("suzanne.csv");
+	if (!m_mesh) {
+		int numverts = ARRAY_SIZE(verts);
+		int numfaces = ARRAY_SIZE(face_lengths);
+		load_mesh(verts, numverts, NULL, 0, faces, face_lengths, numfaces);
+	}
+	
+	m_samples = (MeshSample *)MEM_mallocN(sizeof(MeshSample) * m_numsamples, "mesh samples");
+}
+
+void MeshSampleTest::TearDown()
+{
+	if (m_samples) {
+		MEM_freeN(m_samples);
+		m_samples = NULL;
+	}
+	
+	unload_mesh();
+}
+
+
+void MeshSampleTest::dump_samples()
+{
+#ifdef TEST_MESH_OUTPUT_FILE
+	int numverts = m_mesh->totvert;
+	
+	int dbg_numverts = numverts + m_numsamples;
+	float (*dbg_verts)[3] = (float (*)[3])MEM_mallocN(sizeof(float[3]) * dbg_numverts, "vertices");
+	for (int i = 0; i < numverts; ++i) {
+		copy_v3_v3(dbg_verts[i], m_mesh->mvert[i].co);
+	}
+	for (int i = 0; i < m_numsamples; ++i) {
+		float nor[3], tang[3];
+		BKE_mesh_sample_eval(m_mesh, &m_samples[i], dbg_verts[numverts + i], nor, tang);
+	}
+	int *dbg_faces = (int *)MEM_mallocN(sizeof(int) * m_mesh->totloop, "faces");
+	int *dbg_face_lengths = (int *)MEM_mallocN(sizeof(int) * m_mesh->totpoly, "face_lengths");
+	int loopstart = 0;
+	for (int i = 0; i < m_mesh->totpoly; ++i) {
+		const MPoly *mp = &m_mesh->mpoly[i];
+		dbg_face_lengths[i] = mp->totloop;
+		for (int k = 0; k < mp->totloop; ++k) {
+			dbg_faces[loopstart + k] = m_mesh->mloop[mp->loopstart + k].v;
+		}
+		loopstart += mp->totloop;
+	}
+	Mesh *dbg_mesh = BKE_mesh_test_from_data(dbg_verts, dbg_numverts, NULL, 0, dbg_faces, dbg_face_lengths, m_mesh->totpoly);
+	MEM_freeN(dbg_verts);
+	MEM_freeN(dbg_faces);
+	MEM_freeN(dbg_face_lengths);
+	
+	std::stringstream filename;
+	filename << TEST_MESH_OUTPUT_FILE << get_testname() << ".py";
+	std::fstream s(filename.str(), s.trunc | s.out);
+	
+	BKE_mesh_test_dump_mesh(dbg_mesh, get_testname().c_str(), s);
+	
+	BKE_mesh_free(dbg_mesh);
+	MEM_freeN(dbg_mesh);
+#endif
+}
+
+void MeshSampleTest::compare_samples(const MeshSample *ground_truth)
+{
+	for (int i = 0; i < m_numsamples; ++i) {
+		EXPECT_EQ(ground_truth[i].orig_verts[0], m_samples[i].orig_verts[0]);
+		EXPECT_EQ(ground_truth[i].orig_verts[1], m_samples[i].orig_verts[1]);
+		EXPECT_EQ(ground_truth[i].orig_verts[2], m_samples[i].orig_verts[2]);
+		
+		EXPECT_EQ(ground_truth[i].orig_weights[0], m_samples[i].orig_weights[0]);
+		EXPECT_EQ(ground_truth[i].orig_weights[1], m_samples[i].orig_weights[1]);
+		EXPECT_EQ(ground_truth[i].orig_weights[2], m_samples[i].orig_weights[2]);
+	}
+}
+
+void MeshSampleTest::generate_samples_simple(MeshSampleGenerator *gen)
+{
+	for (int i = 0; i < m_numsamples; ++i) {
+		BKE_mesh_sample_generate(gen, &m_samples[i]);
+	}
+}
+
+void MeshSampleTest::generate_samples_batch(MeshSampleGenerator *gen)
+{
+	BKE_mesh_sample_generate_batch_ex(gen, m_samples, sizeof(MeshSample), m_numsamples, false);
+}
+
+void MeshSampleTest::generate_samples_batch_threaded(MeshSampleGenerator *gen)
+{
+	BKE_mesh_sample_generate_batch_ex(gen, m_samples, sizeof(MeshSample), m_numsamples, true);
+}
+
+void MeshSampleTest::test_samples(MeshSampleGenerator *gen, const MeshSample *ground_truth, int count)
+{
+	BKE_mesh_sample_generator_bind(gen, m_mesh);
+	
+	if (ground_truth) {
+		EXPECT_EQ(count, m_numsamples) << "Ground truth size does not match number of samples";
+		if (count != m_numsamples) {
+			return;
+		}
+		
+		generate_samples_simple(gen);
+		compare_samples(ground_truth);
+	}
+	else {
+		generate_samples_simple(gen);
+		// Use simple sample generation as ground truth if not provided explicitly
+		ground_truth = m_samples;
+	}
+	
+	generate_samples_batch(gen);
+	compare_samples(ground_truth);
+	
+	generate_samples_batch_threaded(gen);
+	compare_samples(ground_truth);
+	
+	BKE_mesh_sample_generator_unbind(gen);
+}
+
+TEST_F(MeshSampleTest, SurfaceVertices)
+{
+	MeshSampleGenerator *gen = BKE_mesh_sample_gen_surface_vertices();
+	ASSERT_TRUE(gen != NULL) << "No generator created";
+	
+	test_samples(gen, NULL, 0);
+	dump_samples();
+	
+	BKE_mesh_sample_free_generator(gen);
+}
+
+TEST_F(MeshSampleTest, SurfaceRandom)
+{
+	MeshSampleGenerator *gen = BKE_mesh_sample_gen_surface_random(m_seed, true, NULL, NULL);
+	ASSERT_TRUE(gen != NULL) << "No generator created";
+	
+	test_samples(gen, NULL, 0);
+	dump_samples();
+	
+	BKE_mesh_sample_free_generator(gen);
+}
+
+const float poisson_disk_mindist = 0.01f;
+
+TEST_F(MeshSampleTest, SurfacePoissonDisk)
+{
+	MeshSampleGenerator *gen = BKE_mesh_sample_gen_surface_poissondisk(m_seed, poisson_disk_mindist, 10000000, NULL, NULL);
+	ASSERT_TRUE(gen != NULL) << "No generator created";
+	
+	test_samples(gen, NULL, 0);
+	dump_samples();
+	
+	BKE_mesh_sample_free_generator(gen);
+}
+
+extern "C" {
+
+static const unsigned int raycast_seed = 85344;
+static const float raycast_radius = 100.0f;
+
+static void* raycast_thread_context_create(void *UNUSED(userdata), int start)
+{
+	RNG *rng = BLI_rng_new(raycast_seed);
+	BLI_rng_skip(rng, start * 2);
+	return rng;
+}
+
+static void raycast_thread_context_free(void *UNUSED(userdata), void *thread_ctx)
+{
+	BLI_rng_free((RNG *)thread_ctx);
+}
+
+static bool raycast_ray(void *UNUSED(userdata), void *thread_ctx, float ray_start[3], float ray_end[3])
+{
+	RNG *rng = (RNG *)thread_ctx;
+	float v[3];
+	{
+		float r;
+		v[2] = (2.0f * BLI_rng_get_float(rng)) - 1.0f;
+		float a = (float)(M_PI * 2.0) * BLI_rng_get_float(rng);
+		if ((r = 1.0f - (v[2] * v[2])) > 0.0f) {
+			r = sqrtf(r);
+			v[0] = r * cosf(a);
+			v[1] = r * sinf(a);
+		}
+		else {
+			v[2] = 1.0f;
+		}
+	}
+	
+	mul_v3_fl(v, raycast_radius);
+	copy_v3_v3(ray_start, v);
+	negate_v3_v3(ray_end, v);
+	return true;
+}
+
+} /*extern "C"*/
+
+TEST_F(MeshSampleTest, SurfaceRaycast)
+{
+	MeshSampleGenerator *gen = BKE_mesh_sample_gen_surface_raycast(
+	                               raycast_thread_context_create, raycast_thread_context_free, raycast_ray, NULL);
+	ASSERT_TRUE(gen != NULL) << "No generator created";
+	
+	test_samples(gen, NULL, 0);
+	dump_samples();
+	
+	BKE_mesh_sample_free_generator(gen);
+}
+
+static const float volume_bbray_density = 0.1f;
+
+TEST_F(MeshSampleTest, VolumeBBRay)
+{
+	MeshSampleGenerator *gen = BKE_mesh_sample_gen_volume_random_bbray(m_seed, volume_bbray_density);
+	ASSERT_TRUE(gen != NULL) << "No generator created";
+	
+	test_samples(gen, NULL, 0);
+	dump_samples();
+	
+	BKE_mesh_sample_free_generator(gen);
+}

tests/gtests/blenkernel/BKE_mesh_test_util.cc

@@ -0,0 +1,319 @@
+/* Apache License, Version 2.0 */
+
+#include <fstream>
+#include <iostream>
+#include <iomanip>
+
+#include "BKE_mesh_test_util.h"
+
+extern "C" {
+#include "MEM_guardedalloc.h"
+
+#include "BLI_math.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+
+#include "BKE_customdata.h"
+#include "BKE_mesh.h"
+}
+
+static void mesh_update(Mesh *mesh, int calc_edges, int calc_tessface)
+{
+	bool tessface_input = false;
+
+	if (mesh->totface > 0 && mesh->totpoly == 0) {
+		BKE_mesh_convert_mfaces_to_mpolys(mesh);
+
+		/* would only be converting back again, don't bother */
+		tessface_input = true;
+	}
+
+	if (calc_edges || ((mesh->totpoly || mesh->totface) && mesh->totedge == 0))
+		BKE_mesh_calc_edges(mesh, calc_edges, true);
+
+	if (calc_tessface) {
+		if (tessface_input == false) {
+			BKE_mesh_tessface_calc(mesh);
+		}
+	}
+	else {
+		/* default state is not to have tessface's so make sure this is the case */
+		BKE_mesh_tessface_clear(mesh);
+	}
+
+	BKE_mesh_calc_normals(mesh);
+}
+
+static void mesh_add_verts(Mesh *mesh, int len)
+{
+	CustomData vdata;
+
+	if (len == 0)
+		return;
+
+	int totvert = mesh->totvert + len;
+	CustomData_copy(&mesh->vdata, &vdata, CD_MASK_MESH, CD_DEFAULT, totvert);
+	CustomData_copy_data(&mesh->vdata, &vdata, 0, 0, mesh->totvert);
+
+	if (!CustomData_has_layer(&vdata, CD_MVERT))
+		CustomData_add_layer(&vdata, CD_MVERT, CD_CALLOC, NULL, totvert);
+
+	CustomData_free(&mesh->vdata, mesh->totvert);
+	mesh->vdata = vdata;
+	BKE_mesh_update_customdata_pointers(mesh, false);
+
+	/* scan the input list and insert the new vertices */
+
+	/* set final vertex list size */
+	mesh->totvert = totvert;
+}
+
+static void mesh_add_edges(Mesh *mesh, int len)
+{
+	CustomData edata;
+	MEdge *medge;
+	int i, totedge;
+
+	if (len == 0)
+		return;
+
+	totedge = mesh->totedge + len;
+
+	/* update customdata  */
+	CustomData_copy(&mesh->edata, &edata, CD_MASK_MESH, CD_DEFAULT, totedge);
+	CustomData_copy_data(&mesh->edata, &edata, 0, 0, mesh->totedge);
+
+	if (!CustomData_has_layer(&edata, CD_MEDGE))
+		CustomData_add_layer(&edata, CD_MEDGE, CD_CALLOC, NULL, totedge);
+
+	CustomData_free(&mesh->edata, mesh->totedge);
+	mesh->edata = edata;
+	BKE_mesh_update_customdata_pointers(mesh, false); /* new edges don't change tessellation */
+
+	/* set default flags */
+	medge = &mesh->medge[mesh->totedge];
+	for (i = 0; i < len; i++, medge++)
+		medge->flag = ME_EDGEDRAW | ME_EDGERENDER;
+
+	mesh->totedge = totedge;
+}
+
+static void mesh_add_loops(Mesh *mesh, int len)
+{
+	CustomData ldata;
+	int totloop;
+
+	if (len == 0)
+		return;
+
+	totloop = mesh->totloop + len;   /* new face count */
+
+	/* update customdata */
+	CustomData_copy(&mesh->ldata, &ldata, CD_MASK_MESH, CD_DEFAULT, totloop);
+	CustomData_copy_data(&mesh->ldata, &ldata, 0, 0, mesh->totloop);
+
+	if (!CustomData_has_layer(&ldata, CD_MLOOP))
+		CustomData_add_layer(&ldata, CD_MLOOP, CD_CALLOC, NULL, totloop);
+
+	CustomData_free(&mesh->ldata, mesh->totloop);
+	mesh->ldata = ldata;
+	BKE_mesh_update_customdata_pointers(mesh, true);
+
+	mesh->totloop = totloop;
+}
+
+static void mesh_add_polys(Mesh *mesh, int len)
+{
+	CustomData pdata;
+	MPoly *mpoly;
+	int i, totpoly;
+
+	if (len == 0)
+		return;
+
+	totpoly = mesh->totpoly + len;   /* new face count */
+
+	/* update customdata */
+	CustomData_copy(&mesh->pdata, &pdata, CD_MASK_MESH, CD_DEFAULT, totpoly);
+	CustomData_copy_data(&mesh->pdata, &pdata, 0, 0, mesh->totpoly);
+
+	if (!CustomData_has_layer(&pdata, CD_MPOLY))
+		CustomData_add_layer(&pdata, CD_MPOLY, CD_CALLOC, NULL, totpoly);
+
+	CustomData_free(&mesh->pdata, mesh->totpoly);
+	mesh->pdata = pdata;
+	BKE_mesh_update_customdata_pointers(mesh, true);
+
+	/* set default flags */
+	mpoly = &mesh->mpoly[mesh->totpoly];
+	for (i = 0; i < len; i++, mpoly++)
+		mpoly->flag = ME_FACE_SEL;
+
+	mesh->totpoly = totpoly;
+}
+
+Mesh* BKE_mesh_test_from_data(
+        const float (*verts)[3], int numverts,
+        const int (*edges)[2], int numedges,
+        const int *loops, const int *face_lengths, int numfaces)
+{
+	Mesh *me = (Mesh *)MEM_callocN(sizeof(Mesh), "Mesh");
+	
+	BKE_mesh_init(me);
+	
+	int numloops = 0;
+	for (int i = 0; i < numfaces; ++i) {
+		numloops += face_lengths[i];
+	}
+	
+	mesh_add_verts(me, numverts);
+	mesh_add_edges(me, numedges);
+	mesh_add_loops(me, numloops);
+	mesh_add_polys(me, numfaces);
+	
+	{
+		MVert *v = me->mvert;
+		for (int i = 0; i < numverts; ++i, ++v) {
+			copy_v3_v3(v->co, verts[i]);
+		}
+	}
+	
+	{
+		MEdge *e = me->medge;
+		for (int i = 0; i < numedges; ++i, ++e) {
+			e->v1 = edges[i][0];
+			e->v2 = edges[i][1];
+		}
+	}
+	
+	{
+		MLoop *l = me->mloop;
+		for (int i = 0; i < numloops; ++i, ++l) {
+			l->v = loops[i];
+		}
+	}
+	
+	{
+		MPoly *p = me->mpoly;
+		int loopstart = 0;
+		for (int i = 0; i < numfaces; ++i, ++p) {
+			int totloop = face_lengths[i];
+			p->loopstart = loopstart;
+			p->totloop = totloop;
+			
+			loopstart += totloop;
+		}
+	}
+	
+	if (numfaces > 0 && numedges == 0) {
+		mesh_update(me, true, false);
+	}
+	
+	return me;
+}
+
+Mesh* BKE_mesh_test_from_csv(const char *filename)
+{
+	std::ifstream ifs (filename, std::ifstream::in);
+	
+	char delim;
+	
+	int numverts, numloops, numfaces;
+	float (*verts)[3] = NULL;
+	int *loops = NULL;
+	int *face_lengths = NULL;
+	
+	ifs >> numverts;
+	ifs >> delim;
+	verts = (float (*)[3])MEM_mallocN(sizeof(float[3]) * numverts, "verts");
+	for (int i = 0; i < numverts; ++i) {
+		ifs >> verts[i][0];
+		ifs >> delim;
+		ifs >> verts[i][1];
+		ifs >> delim;
+		ifs >> verts[i][2];
+		ifs >> delim;
+	}
+	
+	ifs >> numloops;
+	ifs >> delim;
+	loops = (int *)MEM_mallocN(sizeof(int) * numloops, "loops");
+	for (int i = 0; i < numloops; ++i) {
+		ifs >> loops[i];
+		ifs >> delim;
+	}
+	
+	ifs >> numfaces;
+	ifs >> delim;
+	face_lengths = (int *)MEM_mallocN(sizeof(int) * numfaces, "face_lengths");
+	for (int i = 0; i < numfaces; ++i) {
+		ifs >> face_lengths[i];
+		ifs >> delim;
+	}
+	
+	return BKE_mesh_test_from_data(verts, numverts, NULL, 0, loops, face_lengths, numfaces);
+}
+
+void BKE_mesh_test_dump_verts(Mesh *me, std::ostream &str)
+{
+	int numverts = me->totvert;
+	
+	str << std::setprecision(5);
+	
+	MVert *v = me->mvert;
+	str << "[";
+	for (int i = 0; i < numverts; ++i, ++v) {
+		str << "(" << v->co[0] << ", " << v->co[1] << ", " << v->co[2] << "), ";
+	}
+	str << "]";
+}
+
+void BKE_mesh_test_dump_edges(Mesh *me, std::ostream &str)
+{
+	int numedges = me->totedge;
+	
+	MEdge *e = me->medge;
+	str << "[";
+	for (int i = 0; i < numedges; ++i, ++e) {
+		str << "(" << e->v1 << ", " << e->v2 << "), ";
+	}
+	str << "]";
+}
+
+void BKE_mesh_test_dump_faces(Mesh *me, std::ostream &str)
+{
+	int numpolys = me->totpoly;
+	
+	MPoly *p = me->mpoly;
+	str << "[";
+	for (int i = 0; i < numpolys; ++i, ++p) {
+		int totloop = p->totloop;
+		MLoop *l = me->mloop + p->loopstart;
+		
+		str << "(";
+		for (int k = 0; k < totloop; ++k, ++l) {
+			str << l->v << ", ";
+		}
+		str << "), ";
+	}
+	str << "]";
+}
+
+void BKE_mesh_test_dump_mesh(Mesh *me, const char *name, std::ostream &str)
+{
+	str << "import bpy\n";
+	str << "from bpy_extras.object_utils import object_data_add\n";
+	str << "mesh = bpy.data.meshes.new(name=\"" << name << "\")\n";
+	
+	str << "mesh.from_pydata(";
+	str << "vertices=";
+	BKE_mesh_test_dump_verts(me, str);
+	str << ", edges=";
+	BKE_mesh_test_dump_edges(me, str);
+	str << ", faces=";
+	BKE_mesh_test_dump_faces(me, str);
+	str << ")\n";
+	
+	str << "object_data_add(bpy.context, mesh)\n";
+}

tests/gtests/blenkernel/BKE_mesh_test_util.h

@@ -0,0 +1,17 @@
+/* Apache License, Version 2.0 */
+
+#include <iosfwd>
+
+struct Mesh;
+
+struct Mesh* BKE_mesh_test_from_data(
+        const float (*verts)[3], int numverts,
+        const int (*edges)[2], int numedges,
+        const int *loops, const int *face_lengths, int numfaces);
+
+struct Mesh* BKE_mesh_test_from_csv(const char *filename);
+
+void BKE_mesh_test_dump_verts(struct Mesh *me, std::ostream &str);
+void BKE_mesh_test_dump_edges(struct Mesh *me, std::ostream &str);
+void BKE_mesh_test_dump_faces(struct Mesh *me, std::ostream &str);
+void BKE_mesh_test_dump_mesh(struct Mesh *me, const char *name, std::ostream &str);

tests/gtests/blenkernel/CMakeLists.txt

@@ -0,0 +1,57 @@
+# ***** BEGIN GPL LICENSE BLOCK *****
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+# The Original Code is Copyright (C) 2014, Blender Foundation
+# All rights reserved.
+#
+# Contributor(s): Sergey Sharybin
+#
+# ***** END GPL LICENSE BLOCK *****
+
+set(INC
+	.
+	..
+	../../../source/blender/blenlib
+	../../../source/blender/blenkernel
+	../../../source/blender/makesdna
+	../../../source/blender/depsgraph
+	../../../intern/guardedalloc
+)
+
+include_directories(${INC})
+
+set(SRC
+	BKE_mesh_test_util.cc
+	BKE_mesh_sample_test.cc
+
+	BKE_mesh_test_util.h
+)
+
+setup_libdirs()
+get_property(BLENDER_SORTED_LIBS GLOBAL PROPERTY BLENDER_SORTED_LIBS_PROP)
+
+if(WITH_BUILDINFO)
+	set(_buildinfo_src "$<TARGET_OBJECTS:buildinfoobj>")
+else()
+	set(_buildinfo_src "")
+endif()
+
+# For motivation on doubling BLENDER_SORTED_LIBS, see ../bmesh/CMakeLists.txt
+BLENDER_SRC_GTEST(blenkernel "${SRC};${_buildinfo_src}" "${BLENDER_SORTED_LIBS};${BLENDER_SORTED_LIBS}")
+
+unset(_buildinfo_src)
+
+setup_liblinks(blenkernel_test)