Gawain: Add support for rendering using an instance batch (for particles)

intern/gawain/gawain/batch.h

@@ -73,7 +73,7 @@ void Batch_draw(Batch*);
 void Batch_draw_stupid(Batch*);
 void Batch_draw_stupid_instanced(Batch*, unsigned int instance_vbo, int instance_count,
                                  int attrib_nbr, int attrib_stride, int attrib_loc[16], int attrib_size[16]);
-
+void Batch_draw_stupid_instanced_with_batch(Batch*, Batch*);
 
 
 

intern/gawain/src/batch.c

@@ -374,3 +374,69 @@ void Batch_draw_stupid_instanced(Batch* batch, unsigned int instance_vbo, int in
 	// Batch_done_using_program(batch);
 	glBindVertexArray(0);
 	}
+
+void Batch_draw_stupid_instanced_with_batch(Batch* batch_instanced, Batch* batch_instancing)
+	{
+	if (batch_instanced->vao_id)
+		glBindVertexArray(batch_instanced->vao_id);
+	else
+		Batch_prime(batch_instanced);
+
+	if (batch_instanced->program_dirty)
+		Batch_update_program_bindings(batch_instanced);
+
+	VertexBuffer* verts = batch_instancing->verts[0];
+
+	const VertexFormat* format = &verts->format;
+
+	const unsigned attrib_ct = format->attrib_ct;
+	const unsigned stride = format->stride;
+
+	VertexBuffer_use(verts);
+
+	for (unsigned a_idx = 0; a_idx < attrib_ct; ++a_idx)
+		{
+		const Attrib* a = format->attribs + a_idx;
+
+		const GLvoid* pointer = (const GLubyte*)0 + a->offset;
+
+		for (unsigned n_idx = 0; n_idx < a->name_ct; ++n_idx)
+			{
+			const ShaderInput* input = ShaderInterface_attrib(batch_instanced->interface, a->name[n_idx]);
+
+			if (input == NULL) continue;
+
+			glEnableVertexAttribArray(input->location);
+			glVertexAttribDivisor(input->location, 1);
+
+			switch (a->fetch_mode)
+				{
+				case KEEP_FLOAT:
+				case CONVERT_INT_TO_FLOAT:
+					glVertexAttribPointer(input->location, a->comp_ct, a->gl_comp_type, GL_FALSE, stride, pointer);
+					break;
+				case NORMALIZE_INT_TO_FLOAT:
+					glVertexAttribPointer(input->location, a->comp_ct, a->gl_comp_type, GL_TRUE, stride, pointer);
+					break;
+				case KEEP_INT:
+					glVertexAttribIPointer(input->location, a->comp_ct, a->gl_comp_type, stride, pointer);
+				}
+			}
+		}
+
+	// Batch_use_program(batch);
+
+	//gpuBindMatrices(batch->program);
+
+	if (batch_instanced->elem)
+		{
+		const ElementList* el = batch_instanced->elem;
+
+		glDrawElementsInstanced(batch_instanced->gl_prim_type, el->index_ct, GL_UNSIGNED_INT, 0, verts->vertex_ct);
+		}
+	else
+		glDrawArraysInstanced(batch_instanced->gl_prim_type, 0, batch_instanced->verts[0]->vertex_ct, verts->vertex_ct);
+
+	// Batch_done_using_program(batch);
+	glBindVertexArray(0);
+	}

source/blender/draw/intern/draw_manager.c

@@ -1133,18 +1133,11 @@ static void shgroup_dynamic_instance(DRWShadingGroup *shgroup)
 	DRWInterface *interface = shgroup->interface;
 	int buffer_size = 0;
 
-	/* XXX All of this is pretty garbage. Better revisit it later. */
 	if (interface->instance_batch != NULL) {
-		VertexBuffer *vert = interface->instance_batch->verts[0];
-		/* This is double check but we don't want
-		 * VertexBuffer_use() to bind the buffer if it exists. */
-		if (vert->vbo_id == 0) {
-			VertexBuffer_use(vert);
-		}
-		interface->instance_vbo = vert->vbo_id;
-		interface->instance_count = vert->vertex_ct;
+		return;
 	}
 
+	/* TODO We still need this because gawain does not support Matrix attribs. */
 	if (interface->instance_count == 0) {
 		if (interface->instance_vbo) {
 			glDeleteBuffers(1, &interface->instance_vbo);
@@ -1163,11 +1156,6 @@ static void shgroup_dynamic_instance(DRWShadingGroup *shgroup)
 		}
 	}
 
-	if (interface->instance_batch != NULL) {
-		/* Quit just after attribs where specified */
-		return;
-	}
-
 	/* Gather Data */
 	buffer_size = sizeof(float) * interface->attribs_stride * interface->instance_count;
 	float *data = MEM_mallocN(buffer_size, "Instance VBO data");
@@ -1611,7 +1599,10 @@ static void draw_geometry_execute(DRWShadingGroup *shgroup, Batch *geom)
 	DRWInterface *interface = shgroup->interface;
 	/* step 2 : bind vertex array & draw */
 	Batch_set_program(geom, GPU_shader_get_program(shgroup->shader), GPU_shader_get_interface(shgroup->shader));
-	if (interface->instance_vbo) {
+	if (interface->instance_batch) {
+		Batch_draw_stupid_instanced_with_batch(geom, interface->instance_batch);
+	}
+	else if (interface->instance_vbo) {
 		Batch_draw_stupid_instanced(geom, interface->instance_vbo, interface->instance_count, interface->attribs_count,
 		                            interface->attribs_stride, interface->attribs_size, interface->attribs_loc);
 	}
@@ -1737,7 +1728,9 @@ static void draw_shgroup(DRWShadingGroup *shgroup, DRWState pass_state)
 		float obmat[4][4];
 		unit_m4(obmat);
 
-		if (shgroup->type == DRW_SHG_INSTANCE && interface->instance_count > 0) {
+		if (shgroup->type == DRW_SHG_INSTANCE &&
+			(interface->instance_count > 0 || interface->instance_batch != NULL))
+		{
 			GPU_SELECT_LOAD_IF_PICKSEL_LIST(&shgroup->calls);
 			draw_geometry(shgroup, shgroup->instance_geom, obmat, NULL);
 		}

source/blender/draw/modes/object_mode.c

@@ -1486,9 +1486,6 @@ static void OBJECT_cache_populate_particles(Object *ob,
 
 				if (shgrp) {
 					if (draw_as != PART_DRAW_DOT) {
-						DRW_shgroup_attrib_float(shgrp, "pos", 3);
-						DRW_shgroup_attrib_float(shgrp, "rot", 4);
-						DRW_shgroup_attrib_float(shgrp, "val", 1);
 						DRW_shgroup_uniform_short_to_int(shgrp, "draw_size", &part->draw_size, 1);
 						DRW_shgroup_uniform_float(shgrp, "pixel_size", DRW_viewport_pixelsize_get(), 1);
 						DRW_shgroup_instance_batch(shgrp, geom);