Workbench: Support Active Vertex Color

Currently it is not possible to view the vertex colors of an object. To
optimize the workflow, workbench will need to support Vertex Colors.

The Vertex Colors is a new option in `shading->color_type`. When objects
do not have vertex color, the objects will be rendered with the
`V3D_SHADING_OBJECT_COLOR`.

In order to support vertex colors in workbench the current texture/solid
shading structure is migrated to a primary shaders and fallback shaders.

Fix: T57000

Reviewers: brecht, fclem

Differential Revision: https://developer.blender.org/D4694

1 files changed, 30 insertions, 20 deletions

diff --git a/source/blender/draw/engines/workbench/workbench_forward.c b/source/blender/draw/engines/workbench/workbench_forward.c
index 782e85597d7..1117ee0126b 100644
--- a/source/blender/draw/engines/workbench/workbench_forward.c
+++ b/source/blender/draw/engines/workbench/workbench_forward.c
@@ -137,7 +137,8 @@ WORKBENCH_MaterialData *workbench_forward_get_or_create_material_data(WORKBENCH_
                                                                       Image *ima,
                                                                       ImageUser *iuser,
                                                                       int color_type,
-                                                                      int interp)
+                                                                      int interp,
+                                                                      bool is_sculpt_mode)
 {
   const DRWContextState *draw_ctx = DRW_context_state_get();
   WORKBENCH_FORWARD_Shaders *sh_data = &e_data.sh_data[draw_ctx->sh_cfg];
@@ -168,9 +169,9 @@ WORKBENCH_MaterialData *workbench_forward_get_or_create_material_data(WORKBENCH_
     material = MEM_mallocN(sizeof(WORKBENCH_MaterialData), __func__);
 
     /* transparent accum */
-    grp = DRW_shgroup_create(color_type == V3D_SHADING_TEXTURE_COLOR ?
-                                 wpd->transparent_accum_texture_sh :
-                                 wpd->transparent_accum_sh,
+    grp = DRW_shgroup_create(wpd->shading.color_type == color_type ?
+                                 wpd->transparent_accum_sh :
+                                 wpd->transparent_accum_uniform_sh,
                              psl->transparent_accum_pass);
     DRW_shgroup_uniform_block(grp, "world_block", wpd->world_ubo);
     DRW_shgroup_uniform_float_copy(grp, "alpha", wpd->shading.xray_alpha);
@@ -194,7 +195,7 @@ WORKBENCH_MaterialData *workbench_forward_get_or_create_material_data(WORKBENCH_
     material->shgrp = grp;
 
     /* Depth */
-    if (workbench_material_determine_color_type(wpd, material->ima, ob) ==
+    if (workbench_material_determine_color_type(wpd, material->ima, ob, is_sculpt_mode) ==
         V3D_SHADING_TEXTURE_COLOR) {
       material->shgrp_object_outline = DRW_shgroup_create(sh_data->object_outline_texture_sh,
                                                           psl->object_outline_pass);
@@ -217,15 +218,15 @@ WORKBENCH_MaterialData *workbench_forward_get_or_create_material_data(WORKBENCH_
 }
 
 static GPUShader *ensure_forward_accum_shaders(WORKBENCH_PrivateData *wpd,
-                                               bool use_textures,
+                                               bool is_uniform_color,
                                                bool is_hair,
                                                eGPUShaderConfig sh_cfg)
 {
   WORKBENCH_FORWARD_Shaders *sh_data = &e_data.sh_data[sh_cfg];
-  int index = workbench_material_get_accum_shader_index(wpd, use_textures, is_hair);
+  int index = workbench_material_get_accum_shader_index(wpd, is_uniform_color, is_hair);
   if (sh_data->transparent_accum_sh_cache[index] == NULL) {
     const GPUShaderConfigData *sh_cfg_data = &GPU_shader_cfg_data[sh_cfg];
-    char *defines = workbench_material_build_defines(wpd, use_textures, is_hair);
+    char *defines = workbench_material_build_defines(wpd, is_uniform_color, is_hair);
     char *transparent_accum_vert = workbench_build_forward_vert(is_hair);
     char *transparent_accum_frag = workbench_build_forward_transparent_accum_frag();
     sh_data->transparent_accum_sh_cache[index] = GPU_shader_create_from_arrays({
@@ -258,8 +259,8 @@ void workbench_forward_choose_shaders(WORKBENCH_PrivateData *wpd, eGPUShaderConf
   wpd->composite_sh = ensure_forward_composite_shaders(wpd);
   wpd->transparent_accum_sh = ensure_forward_accum_shaders(wpd, false, false, sh_cfg);
   wpd->transparent_accum_hair_sh = ensure_forward_accum_shaders(wpd, false, true, sh_cfg);
-  wpd->transparent_accum_texture_sh = ensure_forward_accum_shaders(wpd, true, false, sh_cfg);
-  wpd->transparent_accum_texture_hair_sh = ensure_forward_accum_shaders(wpd, true, true, sh_cfg);
+  wpd->transparent_accum_uniform_sh = ensure_forward_accum_shaders(wpd, true, false, sh_cfg);
+  wpd->transparent_accum_uniform_hair_sh = ensure_forward_accum_shaders(wpd, true, true, sh_cfg);
 }
 
 void workbench_forward_outline_shaders_ensure(WORKBENCH_PrivateData *wpd, eGPUShaderConfig sh_cfg)
@@ -497,13 +498,13 @@ static void workbench_forward_cache_populate_particles(WORKBENCH_Data *vedata, O
       ImageUser *iuser;
       int interp;
       workbench_material_get_image_and_mat(ob, part->omat, &image, &iuser, &interp, &mat);
-      int color_type = workbench_material_determine_color_type(wpd, image, ob);
+      int color_type = workbench_material_determine_color_type(wpd, image, ob, false);
       WORKBENCH_MaterialData *material = workbench_forward_get_or_create_material_data(
-          vedata, ob, mat, image, iuser, color_type, interp);
+          vedata, ob, mat, image, iuser, color_type, interp, false);
 
-      struct GPUShader *shader = (color_type != V3D_SHADING_TEXTURE_COLOR) ?
+      struct GPUShader *shader = (wpd->shading.color_type == color_type) ?
                                      wpd->transparent_accum_hair_sh :
-                                     wpd->transparent_accum_texture_hair_sh;
+                                     wpd->transparent_accum_uniform_hair_sh;
       DRWShadingGroup *shgrp = DRW_shgroup_hair_create(
           ob, psys, md, psl->transparent_accum_pass, shader);
       DRW_shgroup_uniform_block(shgrp, "world_block", wpd->world_ubo);
@@ -579,9 +580,9 @@ void workbench_forward_cache_populate(WORKBENCH_Data *vedata, Object *ob)
           ImageUser *iuser;
           int interp;
           workbench_material_get_image_and_mat(ob, i + 1, &image, &iuser, &interp, &mat);
-          int color_type = workbench_material_determine_color_type(wpd, image, ob);
+          int color_type = workbench_material_determine_color_type(wpd, image, ob, is_sculpt_mode);
           material = workbench_forward_get_or_create_material_data(
-              vedata, ob, mat, image, iuser, color_type, interp);
+              vedata, ob, mat, image, iuser, color_type, interp, is_sculpt_mode);
           DRW_shgroup_call_object_add(material->shgrp_object_outline, geom_array[i], ob);
           DRW_shgroup_call_object_add(material->shgrp, geom_array[i], ob);
         }
@@ -594,12 +595,21 @@ void workbench_forward_cache_populate(WORKBENCH_Data *vedata, Object *ob)
       if (ELEM(wpd->shading.color_type,
                V3D_SHADING_SINGLE_COLOR,
                V3D_SHADING_OBJECT_COLOR,
-               V3D_SHADING_RANDOM_COLOR)) {
+               V3D_SHADING_RANDOM_COLOR,
+               V3D_SHADING_VERTEX_COLOR)) {
         /* No material split needed */
-        struct GPUBatch *geom = DRW_cache_object_surface_get(ob);
+        int color_type = workbench_material_determine_color_type(wpd, NULL, ob, is_sculpt_mode);
+
+        struct GPUBatch *geom;
+        if (color_type == V3D_SHADING_VERTEX_COLOR) {
+          geom = DRW_cache_mesh_surface_vertpaint_get(ob);
+        }
+        else {
+          geom = DRW_cache_object_surface_get(ob);
+        }
         if (geom) {
           material = workbench_forward_get_or_create_material_data(
-              vedata, ob, NULL, NULL, NULL, wpd->shading.color_type, 0);
+              vedata, ob, NULL, NULL, NULL, color_type, 0, is_sculpt_mode);
           if (is_sculpt_mode) {
             DRW_shgroup_call_sculpt_add(material->shgrp_object_outline, ob, ob->obmat);
             if (!is_wire) {
@@ -631,7 +641,7 @@ void workbench_forward_cache_populate(WORKBENCH_Data *vedata, Object *ob)
 
             Material *mat = give_current_material(ob, i + 1);
             material = workbench_forward_get_or_create_material_data(
-                vedata, ob, mat, NULL, NULL, V3D_SHADING_MATERIAL_COLOR, 0);
+                vedata, ob, mat, NULL, NULL, V3D_SHADING_MATERIAL_COLOR, 0, is_sculpt_mode);
             if (is_sculpt_mode) {
               DRW_shgroup_call_sculpt_add(material->shgrp_object_outline, ob, ob->obmat);
               if (!is_wire) {