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, 39 insertions, 14 deletions

diff --git a/source/blender/draw/engines/workbench/workbench_materials.c b/source/blender/draw/engines/workbench/workbench_materials.c
index 76f035562e5..1473b7df279 100644
--- a/source/blender/draw/engines/workbench/workbench_materials.c
+++ b/source/blender/draw/engines/workbench/workbench_materials.c
@@ -41,13 +41,9 @@
 void workbench_material_update_data(WORKBENCH_PrivateData *wpd,
                                     Object *ob,
                                     Material *mat,
-                                    WORKBENCH_MaterialData *data)
+                                    WORKBENCH_MaterialData *data,
+                                    int color_type)
 {
-  /* When V3D_SHADING_TEXTURE_COLOR is active, use V3D_SHADING_MATERIAL_COLOR as fallback when no
-   * texture could be determined */
-  int color_type = wpd->shading.color_type == V3D_SHADING_TEXTURE_COLOR ?
-                       V3D_SHADING_MATERIAL_COLOR :
-                       wpd->shading.color_type;
   copy_v3_fl3(data->diffuse_color, 0.8f, 0.8f, 0.8f);
   copy_v3_v3(data->base_color, data->diffuse_color);
   copy_v3_fl3(data->specular_color, 0.05f, 0.05f, 0.05f); /* Dielectric: 5% reflective. */
@@ -59,6 +55,10 @@ void workbench_material_update_data(WORKBENCH_PrivateData *wpd,
     copy_v3_v3(data->diffuse_color, wpd->shading.single_color);
     copy_v3_v3(data->base_color, data->diffuse_color);
   }
+  else if (color_type == V3D_SHADING_ERROR_COLOR) {
+    copy_v3_fl3(data->diffuse_color, 0.8, 0.0, 0.8);
+    copy_v3_v3(data->base_color, data->diffuse_color);
+  }
   else if (color_type == V3D_SHADING_RANDOM_COLOR) {
     uint hash = BLI_ghashutil_strhash_p_murmur(ob->id.name);
     if (ob->id.lib) {
@@ -76,7 +76,7 @@ void workbench_material_update_data(WORKBENCH_PrivateData *wpd,
     data->alpha *= ob->color[3];
   }
   else {
-    /* V3D_SHADING_MATERIAL_COLOR */
+    /* V3D_SHADING_MATERIAL_COLOR or V3D_SHADING_TEXTURE_COLOR */
     if (mat) {
       data->alpha *= mat->a;
       if (SPECULAR_HIGHLIGHT_ENABLED(wpd)) {
@@ -97,13 +97,19 @@ void workbench_material_update_data(WORKBENCH_PrivateData *wpd,
 
 char *workbench_material_build_defines(WORKBENCH_PrivateData *wpd,
                                        bool is_uniform_color,
-                                       bool is_hair)
+                                       bool is_hair,
+                                       bool is_texture_painting)
 {
   char *str = NULL;
   bool use_textures = (wpd->shading.color_type == V3D_SHADING_TEXTURE_COLOR) && !is_uniform_color;
   bool use_vertex_colors = (wpd->shading.color_type == V3D_SHADING_VERTEX_COLOR) &&
                            !is_uniform_color;
 
+  if (is_texture_painting) {
+    use_textures = true;
+    use_vertex_colors = false;
+  }
+
   DynStr *ds = BLI_dynstr_new();
 
   if (wpd->shading.flag & V3D_SHADING_OBJECT_OUTLINE) {
@@ -130,7 +136,7 @@ char *workbench_material_build_defines(WORKBENCH_PrivateData *wpd,
   if (OBJECT_ID_PASS_ENABLED(wpd)) {
     BLI_dynstr_append(ds, "#define OBJECT_ID_PASS_ENABLED\n");
   }
-  if (MATDATA_PASS_ENABLED(wpd)) {
+  if (workbench_is_matdata_pass_enabled(wpd)) {
     BLI_dynstr_append(ds, "#define MATDATA_PASS_ENABLED\n");
   }
   if (NORMAL_VIEWPORT_PASS_ENABLED(wpd)) {
@@ -193,22 +199,27 @@ int workbench_material_get_composite_shader_index(WORKBENCH_PrivateData *wpd)
   SET_FLAG_FROM_TEST(index, wpd->shading.flag & V3D_SHADING_SHADOW, 1 << 2);
   SET_FLAG_FROM_TEST(index, wpd->shading.flag & V3D_SHADING_CAVITY, 1 << 3);
   SET_FLAG_FROM_TEST(index, wpd->shading.flag & V3D_SHADING_OBJECT_OUTLINE, 1 << 4);
-  SET_FLAG_FROM_TEST(index, MATDATA_PASS_ENABLED(wpd), 1 << 5);
+  SET_FLAG_FROM_TEST(index, workbench_is_matdata_pass_enabled(wpd), 1 << 5);
   BLI_assert(index < MAX_COMPOSITE_SHADERS);
   return index;
 }
 
 int workbench_material_get_prepass_shader_index(WORKBENCH_PrivateData *wpd,
                                                 bool is_uniform_color,
-                                                bool is_hair)
+                                                bool is_hair,
+                                                bool is_texture_painting)
 {
   bool use_textures = (wpd->shading.color_type == V3D_SHADING_TEXTURE_COLOR) && !is_uniform_color;
   bool use_vertex_colors = (wpd->shading.color_type == V3D_SHADING_VERTEX_COLOR) &&
                            !is_uniform_color;
+  if (is_texture_painting) {
+    use_textures = true;
+    use_vertex_colors = false;
+  }
   /* NOTE: change MAX_PREPASS_SHADERS accordingly when modifying this function. */
   int index = 0;
   SET_FLAG_FROM_TEST(index, is_hair, 1 << 0);
-  SET_FLAG_FROM_TEST(index, MATDATA_PASS_ENABLED(wpd), 1 << 1);
+  SET_FLAG_FROM_TEST(index, workbench_is_matdata_pass_enabled(wpd), 1 << 1);
   SET_FLAG_FROM_TEST(index, OBJECT_ID_PASS_ENABLED(wpd), 1 << 2);
   SET_FLAG_FROM_TEST(index, NORMAL_VIEWPORT_PASS_ENABLED(wpd), 1 << 3);
   SET_FLAG_FROM_TEST(index, MATCAP_ENABLED(wpd), 1 << 4);
@@ -220,11 +231,18 @@ int workbench_material_get_prepass_shader_index(WORKBENCH_PrivateData *wpd,
 
 int workbench_material_get_accum_shader_index(WORKBENCH_PrivateData *wpd,
                                               bool is_uniform_color,
-                                              bool is_hair)
+                                              bool is_hair,
+                                              bool is_texture_painting)
 {
   bool use_textures = (wpd->shading.color_type == V3D_SHADING_TEXTURE_COLOR) && !is_uniform_color;
   bool use_vertex_colors = (wpd->shading.color_type == V3D_SHADING_VERTEX_COLOR) &&
                            !is_uniform_color;
+  if (is_texture_painting) {
+    use_textures = true;
+    use_vertex_colors = false;
+    is_hair = false;
+  }
+
   /* NOTE: change MAX_ACCUM_SHADERS accordingly when modifying this function. */
   int index = 0;
   /* 2 bits FLAT/STUDIO/MATCAP + Specular highlight */
@@ -253,6 +271,13 @@ int workbench_material_determine_color_type(WORKBENCH_PrivateData *wpd,
   if (color_type == V3D_SHADING_VERTEX_COLOR && (me == NULL || me->mloopcol == NULL)) {
     color_type = V3D_SHADING_OBJECT_COLOR;
   }
+
+  /* Force V3D_SHADING_TEXTURE_COLOR for active object when in texture painting
+   * no matter the shading color that the user has chosen, when there is no
+   * texture we will render the object with the error color */
+  if (workbench_is_object_in_texture_paint_mode(ob)) {
+    color_type = ima ? V3D_SHADING_TEXTURE_COLOR : V3D_SHADING_ERROR_COLOR;
+  }
   return color_type;
 }
 
@@ -292,7 +317,7 @@ void workbench_material_shgroup_uniform(WORKBENCH_PrivateData *wpd,
                                         const bool deferred,
                                         const int interp)
 {
-  if (deferred && !MATDATA_PASS_ENABLED(wpd)) {
+  if (deferred && !workbench_is_matdata_pass_enabled(wpd)) {
     return;
   }