TexturePaint: Force Workbench Texture Color Mode

When in texture paint mode and in solid mode the object that is being
texture painted will be rendered by the workbench engine with textures.
All other objects would render the same. For other cases the texture paint
draw engine will still draw the texture.

The texture mode draw engine now only drawn the masks. The opacity
sliders influences the texture mask.

This change has been implemented conserably. In the future we need to
look into making this better, like adding support that every object
can be colored differently. Currently when rendering in the workbench
we can have up to 3 different color types active (what the user selected,
the fallback in case no materials have been configured and this one,
forcing textures)

Reviewed By: fclem, brecht

Differential Revision: https://developer.blender.org/D5190

1 files changed, 88 insertions, 26 deletions

diff --git a/source/blender/draw/engines/workbench/workbench_forward.c b/source/blender/draw/engines/workbench/workbench_forward.c
index 9245d13eab0..5e8cbf71c1e 100644
--- a/source/blender/draw/engines/workbench/workbench_forward.c
+++ b/source/blender/draw/engines/workbench/workbench_forward.c
@@ -141,8 +141,7 @@ WORKBENCH_MaterialData *workbench_forward_get_or_create_material_data(WORKBENCH_
                                                                       Image *ima,
                                                                       ImageUser *iuser,
                                                                       int color_type,
-                                                                      int interp,
-                                                                      bool use_sculpt_pbvh)
+                                                                      int interp)
 {
   const DRWContextState *draw_ctx = DRW_context_state_get();
   WORKBENCH_FORWARD_Shaders *sh_data = &e_data.sh_data[draw_ctx->sh_cfg];
@@ -160,7 +159,7 @@ WORKBENCH_MaterialData *workbench_forward_get_or_create_material_data(WORKBENCH_
   DRWShadingGroup *grp;
 
   /* Solid */
-  workbench_material_update_data(wpd, ob, mat, &material_template);
+  workbench_material_update_data(wpd, ob, mat, &material_template, color_type);
   material_template.object_id = OBJECT_ID_PASS_ENABLED(wpd) ? engine_object_data->object_id : 1;
   material_template.color_type = color_type;
   material_template.ima = ima;
@@ -173,10 +172,15 @@ WORKBENCH_MaterialData *workbench_forward_get_or_create_material_data(WORKBENCH_
     material = MEM_mallocN(sizeof(WORKBENCH_MaterialData), __func__);
 
     /* transparent accum */
-    grp = DRW_shgroup_create(wpd->shading.color_type == color_type ?
-                                 wpd->transparent_accum_sh :
-                                 wpd->transparent_accum_uniform_sh,
-                             psl->transparent_accum_pass);
+    /* select the correct transparent accum shader */
+    GPUShader *shader = (wpd->shading.color_type == color_type) ?
+                            wpd->transparent_accum_sh :
+                            wpd->transparent_accum_uniform_sh;
+    if (color_type == V3D_SHADING_TEXTURE_COLOR) {
+      shader = wpd->transparent_accum_textured_sh;
+    }
+
+    grp = DRW_shgroup_create(shader, psl->transparent_accum_pass);
     DRW_shgroup_uniform_block(grp, "world_block", wpd->world_ubo);
     DRW_shgroup_uniform_float_copy(grp, "alpha", material_template.alpha);
     DRW_shgroup_uniform_vec4(grp, "viewvecs[0]", (float *)wpd->viewvecs, 3);
@@ -199,8 +203,7 @@ WORKBENCH_MaterialData *workbench_forward_get_or_create_material_data(WORKBENCH_
     material->shgrp = grp;
 
     /* Depth */
-    if (workbench_material_determine_color_type(wpd, material->ima, ob, use_sculpt_pbvh) ==
-        V3D_SHADING_TEXTURE_COLOR) {
+    if (color_type == V3D_SHADING_TEXTURE_COLOR) {
       material->shgrp_object_outline = DRW_shgroup_create(sh_data->object_outline_texture_sh,
                                                           psl->object_outline_pass);
       GPUTexture *tex = GPU_texture_from_blender(material->ima, material->iuser, GL_TEXTURE_2D);
@@ -223,13 +226,16 @@ WORKBENCH_MaterialData *workbench_forward_get_or_create_material_data(WORKBENCH_
 static GPUShader *ensure_forward_accum_shaders(WORKBENCH_PrivateData *wpd,
                                                bool is_uniform_color,
                                                bool is_hair,
+                                               bool is_texture_painting,
                                                eGPUShaderConfig sh_cfg)
 {
   WORKBENCH_FORWARD_Shaders *sh_data = &e_data.sh_data[sh_cfg];
-  int index = workbench_material_get_accum_shader_index(wpd, is_uniform_color, is_hair);
+  int index = workbench_material_get_accum_shader_index(
+      wpd, is_uniform_color, is_hair, is_texture_painting);
   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, is_uniform_color, is_hair);
+    char *defines = workbench_material_build_defines(
+        wpd, is_uniform_color, is_hair, is_texture_painting);
     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({
@@ -248,7 +254,7 @@ static GPUShader *ensure_forward_composite_shaders(WORKBENCH_PrivateData *wpd)
 {
   int index = OBJECT_OUTLINE_ENABLED(wpd) ? 1 : 0;
   if (e_data.composite_sh_cache[index] == NULL) {
-    char *defines = workbench_material_build_defines(wpd, false, false);
+    char *defines = workbench_material_build_defines(wpd, false, false, false);
     char *composite_frag = workbench_build_forward_composite_frag();
     e_data.composite_sh_cache[index] = DRW_shader_create_fullscreen(composite_frag, defines);
     MEM_freeN(composite_frag);
@@ -260,10 +266,14 @@ static GPUShader *ensure_forward_composite_shaders(WORKBENCH_PrivateData *wpd)
 void workbench_forward_choose_shaders(WORKBENCH_PrivateData *wpd, eGPUShaderConfig sh_cfg)
 {
   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_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);
+  wpd->transparent_accum_sh = ensure_forward_accum_shaders(wpd, false, false, false, sh_cfg);
+  wpd->transparent_accum_hair_sh = ensure_forward_accum_shaders(wpd, false, true, false, sh_cfg);
+  wpd->transparent_accum_uniform_sh = ensure_forward_accum_shaders(
+      wpd, true, false, false, sh_cfg);
+  wpd->transparent_accum_uniform_hair_sh = ensure_forward_accum_shaders(
+      wpd, true, true, false, sh_cfg);
+  wpd->transparent_accum_textured_sh = ensure_forward_accum_shaders(
+      wpd, false, false, true, sh_cfg);
 }
 
 void workbench_forward_outline_shaders_ensure(WORKBENCH_PrivateData *wpd, eGPUShaderConfig sh_cfg)
@@ -272,9 +282,9 @@ void workbench_forward_outline_shaders_ensure(WORKBENCH_PrivateData *wpd, eGPUSh
 
   if (sh_data->object_outline_sh == NULL) {
     const GPUShaderConfigData *sh_cfg_data = &GPU_shader_cfg_data[sh_cfg];
-    char *defines = workbench_material_build_defines(wpd, false, false);
-    char *defines_texture = workbench_material_build_defines(wpd, true, false);
-    char *defines_hair = workbench_material_build_defines(wpd, false, true);
+    char *defines = workbench_material_build_defines(wpd, false, false, false);
+    char *defines_texture = workbench_material_build_defines(wpd, true, false, false);
+    char *defines_hair = workbench_material_build_defines(wpd, false, true, false);
     char *forward_vert = workbench_build_forward_vert(false);
     char *forward_hair_vert = workbench_build_forward_vert(true);
 
@@ -503,7 +513,7 @@ static void workbench_forward_cache_populate_particles(WORKBENCH_Data *vedata, O
       workbench_material_get_image_and_mat(ob, part->omat, &image, &iuser, &interp, &mat);
       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, false);
+          vedata, ob, mat, image, iuser, color_type, interp);
 
       struct GPUShader *shader = (wpd->shading.color_type == color_type) ?
                                      wpd->transparent_accum_hair_sh :
@@ -533,6 +543,53 @@ static void workbench_forward_cache_populate_particles(WORKBENCH_Data *vedata, O
     }
   }
 }
+static void workbench_forward_cache_populate_texture_paint_mode(WORKBENCH_Data *vedata, Object *ob)
+{
+  WORKBENCH_StorageList *stl = vedata->stl;
+  WORKBENCH_PrivateData *wpd = stl->g_data;
+  const DRWContextState *draw_ctx = DRW_context_state_get();
+
+  Scene *scene = draw_ctx->scene;
+  const bool use_sculpt_pbvh = BKE_sculptsession_use_pbvh_draw(ob, draw_ctx->v3d);
+  WORKBENCH_MaterialData *material;
+
+  /* Force workbench to render active object textured when in texture paint mode */
+  const ImagePaintSettings *imapaint = &scene->toolsettings->imapaint;
+
+  /* Single Image mode */
+  if (imapaint->mode == IMAGEPAINT_MODE_IMAGE) {
+    Image *image = imapaint->canvas;
+    int interp = (imapaint->interp == IMAGEPAINT_INTERP_LINEAR) ? SHD_INTERP_LINEAR :
+                                                                  SHD_INTERP_CLOSEST;
+    int color_type = workbench_material_determine_color_type(wpd, image, ob, use_sculpt_pbvh);
+    struct GPUBatch *geom = DRW_cache_mesh_surface_texpaint_single_get(ob);
+    material = workbench_forward_get_or_create_material_data(
+        vedata, ob, NULL, image, NULL, color_type, interp);
+
+    DRW_shgroup_call(material->shgrp, geom, ob);
+    DRW_shgroup_call(material->shgrp_object_outline, geom, ob);
+  }
+  else {
+    /* IMAGEPAINT_MODE_MATERIAL */
+    const int materials_len = MAX2(1, ob->totcol);
+    struct GPUBatch **geom_array = DRW_cache_mesh_surface_texpaint_get(ob);
+    for (int i = 0; i < materials_len; i++) {
+      if (geom_array != NULL && geom_array[i] != NULL) {
+        Material *mat;
+        Image *image;
+        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, use_sculpt_pbvh);
+        material = workbench_forward_get_or_create_material_data(
+            vedata, ob, mat, image, iuser, color_type, interp);
+
+        DRW_shgroup_call(material->shgrp, geom_array[i], ob);
+        DRW_shgroup_call(material->shgrp_object_outline, geom_array[i], ob);
+      }
+    }
+  }
+}
 
 void workbench_forward_cache_populate(WORKBENCH_Data *vedata, Object *ob)
 {
@@ -571,8 +628,13 @@ void workbench_forward_cache_populate(WORKBENCH_Data *vedata, Object *ob)
     const bool use_sculpt_pbvh = BKE_sculptsession_use_pbvh_draw(ob, draw_ctx->v3d);
     const int materials_len = MAX2(1, ob->totcol);
     const Mesh *me = (ob->type == OB_MESH) ? ob->data : NULL;
+    const bool use_texture_paint_drawing = workbench_is_object_in_texture_paint_mode(ob) && me &&
+                                           me->mloopuv;
 
-    if (!use_sculpt_pbvh && TEXTURE_DRAWING_ENABLED(wpd) && me && me->mloopuv) {
+    if (use_texture_paint_drawing) {
+      workbench_forward_cache_populate_texture_paint_mode(vedata, ob);
+    }
+    else if (!use_sculpt_pbvh && TEXTURE_DRAWING_ENABLED(wpd) && me && me->mloopuv) {
       struct GPUBatch **geom_array = DRW_cache_mesh_surface_texpaint_get(ob);
       for (int i = 0; i < materials_len; i++) {
         Material *mat;
@@ -582,7 +644,7 @@ void workbench_forward_cache_populate(WORKBENCH_Data *vedata, Object *ob)
         workbench_material_get_image_and_mat(ob, i + 1, &image, &iuser, &interp, &mat);
         int color_type = workbench_material_determine_color_type(wpd, image, ob, use_sculpt_pbvh);
         material = workbench_forward_get_or_create_material_data(
-            vedata, ob, mat, image, iuser, color_type, interp, use_sculpt_pbvh);
+            vedata, ob, mat, image, iuser, color_type, interp);
         DRW_shgroup_call(material->shgrp_object_outline, geom_array[i], ob);
         DRW_shgroup_call(material->shgrp, geom_array[i], ob);
       }
@@ -597,7 +659,7 @@ void workbench_forward_cache_populate(WORKBENCH_Data *vedata, Object *ob)
 
       if (use_sculpt_pbvh) {
         material = workbench_forward_get_or_create_material_data(
-            vedata, ob, NULL, NULL, NULL, color_type, 0, use_sculpt_pbvh);
+            vedata, ob, NULL, NULL, NULL, color_type, 0);
         bool use_vcol = (color_type == V3D_SHADING_VERTEX_COLOR);
         /* TODO(fclem) make this call optional */
         DRW_shgroup_call_sculpt(material->shgrp_object_outline, ob, false, false, false);
@@ -611,7 +673,7 @@ void workbench_forward_cache_populate(WORKBENCH_Data *vedata, Object *ob)
                                     DRW_cache_object_surface_get(ob);
         if (geom) {
           material = workbench_forward_get_or_create_material_data(
-              vedata, ob, NULL, NULL, NULL, color_type, 0, use_sculpt_pbvh);
+              vedata, ob, NULL, NULL, NULL, color_type, 0);
           /* TODO(fclem) make this call optional */
           DRW_shgroup_call(material->shgrp_object_outline, geom, ob);
           if (!is_wire) {
@@ -628,7 +690,7 @@ void workbench_forward_cache_populate(WORKBENCH_Data *vedata, Object *ob)
         for (int i = 0; i < materials_len; ++i) {
           struct 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, use_sculpt_pbvh);
+              vedata, ob, mat, NULL, NULL, V3D_SHADING_MATERIAL_COLOR, 0);
           shgrps[i] = material->shgrp;
         }
         /* TODO(fclem) make this call optional */
@@ -651,7 +713,7 @@ 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, use_sculpt_pbvh);
+                vedata, ob, mat, NULL, NULL, V3D_SHADING_MATERIAL_COLOR, 0);
             /* TODO(fclem) make this call optional */
             DRW_shgroup_call(material->shgrp_object_outline, mat_geom[i], ob);
             if (!is_wire) {