Merge branch 'master' into eevee-gpencil

Now there are tow options to enable the shadows, at material level and layer level.

Also, renamed `show_shadows` to `use_cast_shadows`

release/scripts/startup/bl_ui/properties_data_gpencil.py

@@ -133,7 +133,7 @@ class DATA_PT_gpencil_layers(DataButtonsPanel, Panel):
         else:
             self.draw_layers(context, layout, gpd)
 
-    def draw_layers(self, _context, layout, gpd):
+    def draw_layers(self, context, layout, gpd):
 
         gpl = gpd.layers.active
 
@@ -175,16 +175,18 @@ class DATA_PT_gpencil_layers(DataButtonsPanel, Panel):
             layout = self.layout
             layout.use_property_split = True
             layout.use_property_decorate = True
-            col = layout.column(align=True)
+            row = layout.row(align=True)
+            row.prop(gpl, "blend_mode", text="Blend")
 
-            col = layout.row(align=True)
+            row = layout.row(align=True)
-            col.prop(gpl, "blend_mode", text="Blend")
+            row.prop(gpl, "opacity", text="Opacity", slider=True)
 
-            col = layout.row(align=True)
+            row = layout.row(align=True)
-            col.prop(gpl, "opacity", text="Opacity", slider=True)
+            row.prop(gpl, "use_lights")
 
-            col = layout.row(align=True)
+            row = layout.row(align=True)
-            col.prop(gpl, "use_lights")
+            row.enabled = context.engine == 'BLENDER_EEVEE'
+            row.prop(gpl, "use_cast_shadows")
 
 
 class DATA_PT_gpencil_layer_masks(LayerDataButtonsPanel, GreasePencilLayerMasksPanel, Panel):

release/scripts/startup/bl_ui/properties_material_gpencil.py

@@ -261,7 +261,14 @@ class MATERIAL_PT_gpencil_settings(GPMaterialButtonsPanel, Panel):
 
         ma = context.material
         gpcolor = ma.grease_pencil
-        layout.prop(gpcolor, "pass_index")
+
+        row = layout.row()
+        row.enabled = context.engine == 'BLENDER_EEVEE'
+        row.prop(gpcolor, "use_cast_shadows")
+
+        row = layout.row()
+        row.prop(gpcolor, "pass_index")
+
 
 
 class MATERIAL_PT_gpencil_material_presets(PresetPanel, Panel):

release/scripts/startup/bl_ui/space_dopesheet.py

@@ -731,6 +731,10 @@ class DOPESHEET_PT_gpencil_mode(LayersDopeSheetPanel, Panel):
             row = layout.row(align=True)
             row.prop(gpl, "use_lights")
 
+            row = layout.row(align=True)
+            row.enabled = context.engine == 'BLENDER_EEVEE'
+            row.prop(gpl, "use_cast_shadows")
+
 
 class DOPESHEET_PT_gpencil_layer_masks(LayersDopeSheetPanel, GreasePencilLayerMasksPanel, Panel):
     bl_label = "Masks"

release/scripts/startup/bl_ui/space_topbar.py

@@ -171,6 +171,10 @@ class TOPBAR_PT_gpencil_layers(Panel):
             srow = col.row(align=True)
             srow.prop(gpl, "use_lights")
 
+            srow = col.row(align=True)
+            srow.enabled = context.engine == 'BLENDER_EEVEE'
+            srow.prop(gpl, "use_cast_shadows")
+
         col = row.column()
 
         sub = col.column(align=True)

source/blender/blenkernel/intern/material.c

@@ -295,7 +295,7 @@ void BKE_gpencil_material_attr_init(Material *ma)
     gp_style->texture_pixsize = 100.0f;
     gp_style->mix_factor = 0.5f;
 
-    gp_style->flag |= GP_MATERIAL_STROKE_SHOW;
+    gp_style->flag |= GP_MATERIAL_STROKE_SHOW | GP_MATERIAL_CAST_SHADOWS;
   }
 }
 

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

@@ -131,6 +131,9 @@ void EEVEE_cache_populate(void *vedata, Object *ob)
     else if (ob->type == OB_VOLUME) {
       EEVEE_volumes_cache_object_add(sldata, vedata, draw_ctx->scene, ob);
     }
+    else if (ob->type == OB_GPENCIL) {
+      EEVEE_gpencil_cache_populate(vedata, sldata, ob, &cast_shadow);
+    }
     else if (!USE_SCENE_LIGHT(draw_ctx->v3d)) {
       /* do not add any scene light sources to the cache */
     }

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

@@ -30,9 +30,11 @@
 #include "BLI_rand.h"
 #include "BLI_string_utils.h"
 
+#include "BKE_gpencil.h"
 #include "BKE_paint.h"
 #include "BKE_particle.h"
 
+#include "DNA_gpencil_types.h"
 #include "DNA_hair_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_view3d_types.h"
@@ -42,6 +44,8 @@
 
 #include "DEG_depsgraph_query.h"
 
+#include "ED_screen.h"
+
 #include "eevee_engine.h"
 #include "eevee_lut.h"
 #include "eevee_private.h"
@@ -229,6 +233,14 @@ void EEVEE_materials_init(EEVEE_ViewLayerData *sldata,
   const DRWContextState *draw_ctx = DRW_context_state_get();
   EEVEE_PrivateData *g_data = stl->g_data;
 
+  g_data->cfra = (int)DEG_get_ctime(draw_ctx->depsgraph);
+  /* Grease pencil simplify. */
+  const bool playing = (draw_ctx->evil_C != NULL) ?
+                           ED_screen_animation_playing(CTX_wm_manager(draw_ctx->evil_C)) != NULL :
+                           false;
+  Scene *scene = draw_ctx->scene;
+  g_data->gpencil_simplify_fill = GPENCIL_SIMPLIFY_FILL(scene, playing);
+
   if (!e_data.util_tex) {
     EEVEE_shaders_material_shaders_init();
 
@@ -470,6 +482,7 @@ BLI_INLINE void material_shadow(EEVEE_Data *vedata,
                                 EEVEE_ViewLayerData *sldata,
                                 Material *ma,
                                 bool is_hair,
+                                bool is_gpencil,
                                 EeveeMaterialCache *emc)
 {
   EEVEE_PrivateData *pd = vedata->stl->g_data;
@@ -484,6 +497,7 @@ BLI_INLINE void material_shadow(EEVEE_Data *vedata,
     int mat_options = VAR_MAT_MESH | VAR_MAT_DEPTH;
     SET_FLAG_FROM_TEST(mat_options, use_shadow_shader, VAR_MAT_HASH);
     SET_FLAG_FROM_TEST(mat_options, is_hair, VAR_MAT_HAIR);
+    SET_FLAG_FROM_TEST(mat_options, is_gpencil, VAR_MAT_GPENCIL);
     GPUMaterial *gpumat = (use_shadow_shader) ?
                               EEVEE_material_get(vedata, scene, ma, NULL, mat_options) :
                               EEVEE_material_default_get(scene, ma, mat_options);
@@ -521,7 +535,8 @@ BLI_INLINE void material_shadow(EEVEE_Data *vedata,
 static EeveeMaterialCache material_opaque(EEVEE_Data *vedata,
                                           EEVEE_ViewLayerData *sldata,
                                           Material *ma,
-                                          const bool is_hair)
+                                          const bool is_hair,
+                                          const bool is_gpencil)
 {
   EEVEE_EffectsInfo *effects = vedata->stl->effects;
   EEVEE_PrivateData *pd = vedata->stl->g_data;
@@ -529,7 +544,7 @@ static EeveeMaterialCache material_opaque(EEVEE_Data *vedata,
   const DRWContextState *draw_ctx = DRW_context_state_get();
   Scene *scene = draw_ctx->scene;
 
-  const bool do_cull = !is_hair && (ma->blend_flag & MA_BL_CULL_BACKFACE) != 0;
+  const bool do_cull = !is_gpencil && !is_hair && (ma->blend_flag & MA_BL_CULL_BACKFACE) != 0;
   const bool use_gpumat = (ma->use_nodes && ma->nodetree);
   const bool use_ssrefract = use_gpumat && ((ma->blend_flag & MA_BL_SS_REFRACTION) != 0) &&
                              ((effects->enabled_effects & EFFECT_REFRACT) != 0);
@@ -537,7 +552,7 @@ static EeveeMaterialCache material_opaque(EEVEE_Data *vedata,
 
   /* HACK: Assume the struct will never be smaller than our variations.
    * This allow us to only keep one ghash and avoid bigger keys comparisons/hashing. */
-  void *key = (char *)ma + is_hair;
+  void *key = (char *)ma + is_hair + is_gpencil * 2;
   /* Search for other material instances (sharing the same Material data-block). */
   EeveeMaterialCache **emc_p, *emc;
   if (BLI_ghash_ensure_p(pd->material_hash, key, (void ***)&emc_p)) {
@@ -546,7 +561,7 @@ static EeveeMaterialCache material_opaque(EEVEE_Data *vedata,
 
   *emc_p = emc = BLI_memblock_alloc(sldata->material_cache);
 
-  material_shadow(vedata, sldata, ma, is_hair, emc);
+  material_shadow(vedata, sldata, ma, is_hair, is_gpencil, emc);
 
   {
     /* Depth Pass */
@@ -554,6 +569,7 @@ static EeveeMaterialCache material_opaque(EEVEE_Data *vedata,
     SET_FLAG_FROM_TEST(mat_options, use_ssrefract, VAR_MAT_REFRACT);
     SET_FLAG_FROM_TEST(mat_options, use_depth_shader, VAR_MAT_HASH);
     SET_FLAG_FROM_TEST(mat_options, is_hair, VAR_MAT_HAIR);
+    SET_FLAG_FROM_TEST(mat_options, is_gpencil, VAR_MAT_GPENCIL);
     GPUMaterial *gpumat = (use_depth_shader) ?
                               EEVEE_material_get(vedata, scene, ma, NULL, mat_options) :
                               EEVEE_material_default_get(scene, ma, mat_options);
@@ -595,6 +611,7 @@ static EeveeMaterialCache material_opaque(EEVEE_Data *vedata,
     int mat_options = VAR_MAT_MESH;
     SET_FLAG_FROM_TEST(mat_options, use_ssrefract, VAR_MAT_REFRACT);
     SET_FLAG_FROM_TEST(mat_options, is_hair, VAR_MAT_HAIR);
+    SET_FLAG_FROM_TEST(mat_options, is_gpencil, VAR_MAT_GPENCIL);
     GPUMaterial *gpumat = EEVEE_material_get(vedata, scene, ma, NULL, mat_options);
     const bool use_sss = GPU_material_flag_get(gpumat, GPU_MATFLAG_SSS);
 
@@ -609,7 +626,7 @@ static EeveeMaterialCache material_opaque(EEVEE_Data *vedata,
         psl->material_cull_ps,
     }[option];
     /* Hair are rendered inside the non-cull pass but needs to have a separate cache key */
-    option = option * 2 + is_hair;
+    option = option * 3 + is_hair + is_gpencil * 2;
 
     /* Search for the same shaders usage in the pass. */
     /* HACK: Assume the struct will never be smaller than our variations.
@@ -668,7 +685,7 @@ static EeveeMaterialCache material_transparent(EEVEE_Data *vedata,
                         DRW_STATE_DEPTH_LESS_EQUAL | DRW_STATE_DEPTH_EQUAL |
                         DRW_STATE_BLEND_CUSTOM);
 
-  material_shadow(vedata, sldata, ma, false, &emc);
+  material_shadow(vedata, sldata, ma, false, false, &emc);
 
   if (use_prepass) {
     /* Depth prepass */
@@ -735,15 +752,20 @@ BLI_INLINE Material *eevee_object_material_get(Object *ob, int slot, bool holdou
   return ma;
 }
 
-BLI_INLINE EeveeMaterialCache eevee_material_cache_get(
+BLI_INLINE EeveeMaterialCache eevee_material_cache_get(EEVEE_Data *vedata,
-    EEVEE_Data *vedata, EEVEE_ViewLayerData *sldata, Object *ob, int slot, bool is_hair)
+                                                       EEVEE_ViewLayerData *sldata,
+                                                       Object *ob,
+                                                       int slot,
+                                                       bool is_hair,
+                                                       bool is_gpencil)
 {
   const bool holdout = (ob->base_flag & BASE_HOLDOUT) != 0;
   EeveeMaterialCache matcache;
   Material *ma = eevee_object_material_get(ob, slot, holdout);
   switch (ma->blend_method) {
     case MA_BM_BLEND:
-      if (!is_hair) {
+      /* TODO(fclem) support gpencil transparent materials. */
+      if (!is_hair && !is_gpencil) {
         matcache = material_transparent(vedata, sldata, ma);
         break;
       }
@@ -752,7 +774,7 @@ BLI_INLINE EeveeMaterialCache eevee_material_cache_get(
     case MA_BM_CLIP:
     case MA_BM_HASHED:
     default:
-      matcache = material_opaque(vedata, sldata, ma, is_hair);
+      matcache = material_opaque(vedata, sldata, ma, is_hair, is_gpencil);
       break;
   }
   return matcache;
@@ -766,7 +788,8 @@ static void eevee_hair_cache_populate(EEVEE_Data *vedata,
                                       int matnr,
                                       bool *cast_shadow)
 {
-  EeveeMaterialCache matcache = eevee_material_cache_get(vedata, sldata, ob, matnr - 1, true);
+  EeveeMaterialCache matcache = eevee_material_cache_get(
+      vedata, sldata, ob, matnr - 1, true, false);
 
   if (matcache.depth_grp) {
     *matcache.depth_grp_p = DRW_shgroup_hair_create_sub(ob, psys, md, matcache.depth_grp);
@@ -824,7 +847,7 @@ void EEVEE_materials_cache_populate(EEVEE_Data *vedata,
 
     EeveeMaterialCache *matcache = BLI_array_alloca(matcache, materials_len);
     for (int i = 0; i < materials_len; i++) {
-      matcache[i] = eevee_material_cache_get(vedata, sldata, ob, i, false);
+      matcache[i] = eevee_material_cache_get(vedata, sldata, ob, i, false, false);
     }
 
     /* Only support single volume material for now. */
@@ -930,6 +953,119 @@ void EEVEE_object_hair_cache_populate(EEVEE_Data *vedata,
   eevee_hair_cache_populate(vedata, sldata, ob, NULL, NULL, HAIR_MATERIAL_NR, cast_shadow);
 }
 
+typedef struct gpIterData {
+  EEVEE_PrivateData *pd;
+  Object *ob;
+  DRWShadingGroup *stroke_shadow_grp;
+  DRWShadingGroup *fill_shadow_grp;
+  int cfra;
+  float plane[4];
+} gpIterData;
+
+static void eevee_gpencil_layer_cache_populate(bGPDlayer *gpl,
+                                               bGPDframe *UNUSED(gpf),
+                                               bGPDstroke *UNUSED(gps),
+                                               void *thunk)
+{
+  gpIterData *iter = (gpIterData *)thunk;
+  bGPdata *gpd = (bGPdata *)iter->ob->data;
+
+  const bool is_screenspace = (gpd->flag & GP_DATA_STROKE_KEEPTHICKNESS) != 0;
+  const bool is_stroke_order_3d = (gpd->draw_mode == GP_DRAWMODE_3D);
+
+  float object_scale = mat4_to_scale(iter->ob->obmat);
+  /* Negate thickness sign to tag that strokes are in screen space.
+   * Convert to world units (by default, 1 meter = 2000 px). */
+  float thickness_scale = (is_screenspace) ? -1.0f : (gpd->pixfactor / 2000.0f);
+
+  DRWShadingGroup *grp = iter->stroke_shadow_grp = DRW_shgroup_create_sub(iter->stroke_shadow_grp);
+  DRW_shgroup_uniform_bool_copy(grp, "strokeOrder3d", is_stroke_order_3d);
+  DRW_shgroup_uniform_vec2_copy(grp, "sizeViewportInv", DRW_viewport_invert_size_get());
+  DRW_shgroup_uniform_vec2_copy(grp, "sizeViewport", DRW_viewport_size_get());
+  DRW_shgroup_uniform_float_copy(grp, "thicknessScale", object_scale);
+  DRW_shgroup_uniform_float_copy(grp, "thicknessOffset", (float)gpl->line_change);
+  DRW_shgroup_uniform_float_copy(grp, "thicknessWorldScale", thickness_scale);
+  DRW_shgroup_uniform_vec4_copy(grp, "gpDepthPlane", iter->plane);
+}
+
+static void eevee_gpencil_stroke_cache_populate(bGPDlayer *gpl,
+                                                bGPDframe *UNUSED(gpf),
+                                                bGPDstroke *gps,
+                                                void *thunk)
+{
+  gpIterData *iter = (gpIterData *)thunk;
+
+  MaterialGPencilStyle *gp_style = BKE_gpencil_material_settings(iter->ob, gps->mat_nr + 1);
+
+  const bool cast_layer_shadows = (gpl->flag & GP_LAYER_CAST_SHADOWS) != 0;
+  const bool cast_material_shadows = (gp_style->flag & GP_MATERIAL_CAST_SHADOWS) != 0;
+  const bool simplify_fill = iter->pd->gpencil_simplify_fill;
+  const bool hide_material = (gp_style->flag & GP_MATERIAL_HIDE) != 0;
+  const bool show_stroke = (gp_style->flag & GP_MATERIAL_STROKE_SHOW) != 0;
+  const bool show_fill = (!simplify_fill) && (gps->tot_triangles > 0) &&
+                         (gp_style->flag & GP_MATERIAL_FILL_SHOW) != 0;
+
+  if ((hide_material) || (!cast_layer_shadows) || (!cast_material_shadows)) {
+    return;
+  }
+
+  if (show_fill) {
+    struct GPUBatch *geom = DRW_cache_gpencil_fills_get(iter->ob, iter->cfra);
+    int vfirst = gps->runtime.fill_start * 3;
+    int vcount = gps->tot_triangles * 3;
+    DRW_shgroup_call_range(iter->fill_shadow_grp, iter->ob, geom, vfirst, vcount);
+  }
+
+  if (show_stroke) {
+    struct GPUBatch *geom = DRW_cache_gpencil_strokes_get(iter->ob, iter->cfra);
+    /* Start one vert before to have gl_InstanceID > 0 (see shader). */
+    int vfirst = gps->runtime.stroke_start - 1;
+    /* Include "potential" cyclic vertex and start adj vertex (see shader). */
+    int vcount = gps->totpoints + 1 + 1;
+    DRW_shgroup_call_instance_range(iter->stroke_shadow_grp, iter->ob, geom, vfirst, vcount);
+  }
+}
+
+void EEVEE_gpencil_cache_populate(EEVEE_Data *vedata,
+                                  EEVEE_ViewLayerData *sldata,
+                                  Object *ob,
+                                  bool *cast_shadow)
+{
+  EEVEE_PrivateData *pd = vedata->stl->g_data;
+  EeveeMaterialCache matcache = eevee_material_cache_get(vedata, sldata, ob, 0, false, true);
+
+  gpIterData iter = {
+      .ob = ob,
+      .pd = pd,
+      .stroke_shadow_grp = NULL,
+      .fill_shadow_grp = NULL,
+      .cfra = pd->cfra,
+  };
+
+  // if (gpd->draw_mode == GP_DRAWMODE_2D) {
+  //   gpencil_depth_plane(ob, iter.plane);
+  // }
+
+  if (matcache.shadow_grp) {
+    iter.stroke_shadow_grp = matcache.shadow_grp;
+    iter.fill_shadow_grp = DRW_shgroup_create_sub(matcache.shadow_grp);
+
+    *matcache.shadow_grp_p = matcache.shadow_grp = iter.fill_shadow_grp;
+    *cast_shadow = true;
+  }
+
+  bool any_material_visible = matcache.shadow_grp != NULL;
+  if (any_material_visible) {
+    BKE_gpencil_visible_stroke_iter(NULL,
+                                    ob,
+                                    eevee_gpencil_layer_cache_populate,
+                                    eevee_gpencil_stroke_cache_populate,
+                                    &iter,
+                                    false,
+                                    pd->cfra);
+  }
+}
+
 void EEVEE_materials_cache_finish(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *vedata)
 {
   EEVEE_PrivateData *pd = vedata->stl->g_data;

source/blender/draw/engines/eevee/eevee_private.h

@@ -176,7 +176,7 @@ enum {
   VAR_MAT_MESH = (1 << 0),
   VAR_MAT_VOLUME = (1 << 1),
   VAR_MAT_HAIR = (1 << 2),
-  /* VAR_MAT_PROBE = (1 << 3), UNUSED */
+  VAR_MAT_GPENCIL = (1 << 3),
   VAR_MAT_BLEND = (1 << 4),
   VAR_MAT_LOOKDEV = (1 << 5),
   VAR_MAT_HOLDOUT = (1 << 6),
@@ -1066,6 +1066,11 @@ typedef struct EEVEE_PrivateData {
   /** For rendering planar reflections. */
   struct DRWView *planar_views[MAX_PLANAR];
 
+  /** For rendering Gpencil Objects. */
+  int cfra;
+  /** Simplify grease pencil fill. */
+  bool gpencil_simplify_fill;
+
   int render_timesteps;
   int render_sample_count_per_timestep;
 } EEVEE_PrivateData; /* Transient data */
@@ -1113,6 +1118,10 @@ void EEVEE_object_hair_cache_populate(EEVEE_Data *vedata,
                                       EEVEE_ViewLayerData *sldata,
                                       Object *ob,
                                       bool *cast_shadow);
+void EEVEE_gpencil_cache_populate(EEVEE_Data *vedata,
+                                  EEVEE_ViewLayerData *sldata,
+                                  Object *ob,
+                                  bool *cast_shadow);
 void EEVEE_materials_cache_finish(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_materials_free(void);
 void EEVEE_update_noise(EEVEE_PassList *psl, EEVEE_FramebufferList *fbl, const double offsets[3]);

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

@@ -256,6 +256,9 @@ void EEVEE_render_cache(void *vedata,
       Scene *scene = DEG_get_evaluated_scene(depsgraph);
       EEVEE_volumes_cache_object_add(sldata, vedata, scene, ob);
     }
+    else if (ob->type == OB_GPENCIL) {
+      EEVEE_gpencil_cache_populate(vedata, sldata, ob, &cast_shadow);
+    }
     else if (ob->type == OB_LIGHTPROBE) {
       EEVEE_lightprobes_cache_add(sldata, vedata, ob);
     }

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

@@ -184,6 +184,7 @@ extern char datatoc_common_hair_lib_glsl[];
 extern char datatoc_common_math_lib_glsl[];
 extern char datatoc_common_math_geom_lib_glsl[];
 extern char datatoc_common_view_lib_glsl[];
+extern char datatoc_gpencil_common_lib_glsl[];
 extern char datatoc_gpu_shader_common_obinfos_lib_glsl[];
 
 extern char datatoc_ambient_occlusion_lib_glsl[];
@@ -290,6 +291,7 @@ static void eevee_shader_library_ensure(void)
     DRW_SHADER_LIB_ADD(e_data.lib, common_view_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, common_uniforms_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, gpu_shader_common_obinfos_lib);
+    DRW_SHADER_LIB_ADD(e_data.lib, gpencil_common_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, random_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, renderpass_lib);
     DRW_SHADER_LIB_ADD(e_data.lib, bsdf_common_lib);
@@ -1358,6 +1360,9 @@ static char *eevee_get_defines(int options)
   if ((options & VAR_MAT_HAIR) != 0) {
     BLI_dynstr_append(ds, "#define HAIR_SHADER\n");
   }
+  if ((options & VAR_MAT_GPENCIL) != 0) {
+    BLI_dynstr_append(ds, "#define GPENCIL_SHADER\n");
+  }
   if ((options & VAR_WORLD_PROBE) != 0) {
     BLI_dynstr_append(ds, "#define PROBE_CAPTURE\n");
   }

source/blender/draw/engines/eevee/shaders/prepass_vert.glsl

@@ -1,10 +1,7 @@
 
 #pragma BLENDER_REQUIRE(common_hair_lib.glsl)
 #pragma BLENDER_REQUIRE(common_view_lib.glsl)
-
+#pragma BLENDER_REQUIRE(gpencil_common_lib.glsl)
-#ifndef HAIR_SHADER
-in vec3 pos;
-#endif
 
 void main()
 {
@@ -23,8 +20,11 @@ void main()
                               time,
                               thickness,
                               thick_time);
+#elif defined(GPENCIL_SHADER)
+  /* TODO */
+  vec3 worldPosition = vec3(0.0);
 #else
-  vec3 worldPosition = point_object_to_world(pos);
+  vec3 worldPosition = point_object_to_world(pos.xyz);
 #endif
 
   gl_Position = point_world_to_ndc(worldPosition);
@@ -32,4 +32,8 @@ void main()
 #ifdef CLIP_PLANES
   gl_ClipDistance[0] = dot(vec4(worldPosition.xyz, 1.0), clipPlanes[0]);
 #endif
+
+#if defined(GPENCIL_SHADER)
+  gpencil_vertex();
+#endif
 }

source/blender/draw/engines/eevee/shaders/surface_vert.glsl

@@ -2,9 +2,9 @@
 #pragma BLENDER_REQUIRE(common_hair_lib.glsl)
 #pragma BLENDER_REQUIRE(common_view_lib.glsl)
 #pragma BLENDER_REQUIRE(surface_lib.glsl)
+#pragma BLENDER_REQUIRE(gpencil_common_lib.glsl)
 
-#ifndef HAIR_SHADER
+#if !defined(HAIR_SHADER) && !defined(GPENCIL_SHADER)
-in vec3 pos;
 in vec3 nor;
 #endif
 
@@ -31,12 +31,21 @@ void main()
                               hairThickTime);
   worldNormal = cross(hairTangent, binor);
   vec3 world_pos = pos;
+#elif defined(GPENCIL_SHADER)
+  /* TODO */
+  vec3 pos = vec3(0.0);
+  vec3 nor = vec3(1.0);
+  vec3 world_pos = pos.xyz;
 #else
-  vec3 world_pos = point_object_to_world(pos);
+  vec3 world_pos = point_object_to_world(pos.xyz);
 #endif
 
   gl_Position = point_world_to_ndc(world_pos);
 
+#if defined(GPENCIL_SHADER)
+  gpencil_vertex();
+#endif
+
   /* Used for planar reflections */
   gl_ClipDistance[0] = dot(vec4(world_pos, 1.0), clipPlanes[0]);
 
@@ -54,7 +63,7 @@ void main()
 #    ifdef HAIR_SHADER
   pos = hair_get_strand_pos();
 #    endif
-  pass_attr(pos, NormalMatrix, ModelMatrixInverse);
+  pass_attr(pos.xyz, NormalMatrix, ModelMatrixInverse);
 #  endif
 #endif
 }

source/blender/draw/engines/gpencil/shaders/gpencil_common_lib.glsl

@@ -149,7 +149,7 @@ void blend_mode_output(
   }
 }
 
-IN_OUT ShaderStageInterface
+IN_OUT GpencilShaderStageInterface
 {
   vec4 finalColorMul;
   vec4 finalColorAdd;

source/blender/makesdna/DNA_gpencil_types.h

@@ -550,6 +550,8 @@ typedef enum eGPDlayer_Flag {
   GP_LAYER_FRAMELOCK = (1 << 6),
   /* don't render xray (which is default) */
   GP_LAYER_NO_XRAY = (1 << 7),
+  /* Show render shadows */
+  GP_LAYER_CAST_SHADOWS = (1 << 8),
   /* "volumetric" strokes */
   GP_LAYER_VOLUMETRIC = (1 << 10),
   /* Use Scene lights */

source/blender/makesdna/DNA_material_types.h

@@ -137,6 +137,8 @@ typedef enum eMaterialGPencilStyle_Flag {
   GP_MATERIAL_IS_STROKE_HOLDOUT = (1 << 13),
   /* Material used as fill masking. */
   GP_MATERIAL_IS_FILL_HOLDOUT = (1 << 14),
+  /* Show Eevee shadows */
+  GP_MATERIAL_CAST_SHADOWS = (1 << 15),
 } eMaterialGPencilStyle_Flag;
 
 typedef enum eMaterialGPencilStyle_Mode {

source/blender/makesrna/intern/rna_gpencil.c

@@ -2215,6 +2215,11 @@ static void rna_def_gpencil_layer(BlenderRNA *brna)
       prop, "Use Lights", "Enable the use of lights on stroke and fill materials");
   RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, "rna_GPencil_update");
 
+  prop = RNA_def_property(srna, "use_cast_shadows", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_LAYER_CAST_SHADOWS);
+  RNA_def_property_ui_text(prop, "Cast Shadows", "Show shadows produced by grease pencil object");
+  RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, "rna_GPencil_update");
+
   /* solo mode: Only display frames with keyframe */
   prop = RNA_def_property(srna, "use_solo_mode", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_LAYER_SOLO_MODE);

source/blender/makesrna/intern/rna_material.c

@@ -596,6 +596,11 @@ static void rna_def_material_greasepencil(BlenderRNA *brna)
   RNA_def_property_ui_text(prop, "Show Fill", "Show stroke fills of this material");
   RNA_def_property_update(prop, NC_GPENCIL | ND_SHADING, "rna_MaterialGpencil_update");
 
+  prop = RNA_def_property(srna, "use_cast_shadows", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_MATERIAL_CAST_SHADOWS);
+  RNA_def_property_ui_text(prop, "Cast Shadows", "Show shadows produced by grease pencil object");
+  RNA_def_property_update(prop, NC_GPENCIL | ND_SHADING, "rna_MaterialGpencil_update");
+
   /* Mode to align Dots and Boxes to drawing path and object rotation */
   prop = RNA_def_property(srna, "alignment_mode", PROP_ENUM, PROP_NONE);
   RNA_def_property_enum_bitflag_sdna(prop, NULL, "alignment_mode");