Sculpt Vertex Colors: Initial implementation

Sculpt Vertex Colors is a painting system that runs inside sculpt mode, reusing all its tools and optimizations. This provides much better performance, easier to maintain code and more advanced features (new brush engine, filters, symmetry options, masks and face sets compatibility...). This is also the initial step for future features like vertex painting in Multires and brushes that can sculpt and paint at the same time.

This commit includes:
  - SCULPT_UNDO_COLOR for undo support in sculpt mode
  - SCULPT_UPDATE_COLOR and PBVH flags and rendering
  - Sculpt Color API functions
  - Sculpt capability for sculpt tools (only enabled in the Paint Brush for now)
  - Rendering support in workbench (default to Sculpt Vertex Colors except in Vertex Paint)
  - Conversion operator between MPropCol (Sculpt Vertex Colors) and MLoopCol (Vertex Paint)
  - Remesher reprojection in the Voxel Remehser
  - Paint Brush and Smear Brush with color smoothing in alt-smooth mode
  - Parameters for the new brush engine (density, opacity, flow, wet paint mixing, tip scale) implemented in Sculpt Vertex Colors
  - Color Filter
  - Color picker (uses S shortcut, replaces smooth)
  - Color selector in the top bar

Reviewed By: brecht

Maniphest Tasks: T72866

Differential Revision: https://developer.blender.org/D5975

1 files changed, 21 insertions, 8 deletions

diff --git a/source/blender/blenkernel/intern/paint.c b/source/blender/blenkernel/intern/paint.c
index f26b478c680..151e0006092 100644
--- a/source/blender/blenkernel/intern/paint.c
+++ b/source/blender/blenkernel/intern/paint.c
@@ -1474,8 +1474,12 @@ static bool sculpt_modifiers_active(Scene *scene, Sculpt *sd, Object *ob)
 /**
  * \param need_mask: So that the evaluated mesh that is returned has mask data.
  */
-static void sculpt_update_object(
-    Depsgraph *depsgraph, Object *ob, Mesh *me_eval, bool need_pmap, bool need_mask)
+static void sculpt_update_object(Depsgraph *depsgraph,
+                                 Object *ob,
+                                 Mesh *me_eval,
+                                 bool need_pmap,
+                                 bool need_mask,
+                                 bool need_colors)
 {
   Scene *scene = DEG_get_input_scene(depsgraph);
   Sculpt *sd = scene->toolsettings->sculpt;
@@ -1503,6 +1507,16 @@ static void sculpt_update_object(
     }
   }
 
+  /* Add a color layer if a color tool is used. */
+  Mesh *orig_me = BKE_object_get_original_mesh(ob);
+  if (need_colors) {
+    if (!CustomData_has_layer(&orig_me->vdata, CD_PROP_COLOR)) {
+      CustomData_add_layer(&orig_me->vdata, CD_PROP_COLOR, CD_DEFAULT, NULL, orig_me->totvert);
+      BKE_mesh_update_customdata_pointers(orig_me, true);
+      DEG_id_tag_update(&orig_me->id, ID_RECALC_GEOMETRY);
+    }
+  }
+
   /* tessfaces aren't used and will become invalid */
   BKE_mesh_tessface_clear(me);
 
@@ -1535,6 +1549,7 @@ static void sculpt_update_object(
     ss->multires.modifier = NULL;
     ss->multires.level = 0;
     ss->vmask = CustomData_get_layer(&me->vdata, CD_PAINT_MASK);
+    ss->vcol = CustomData_get_layer(&me->vdata, CD_PROP_COLOR);
   }
 
   /* Sculpt Face Sets. */
@@ -1663,13 +1678,11 @@ void BKE_sculpt_update_object_after_eval(Depsgraph *depsgraph, Object *ob_eval)
 
   BLI_assert(me_eval != NULL);
 
-  sculpt_update_object(depsgraph, ob_orig, me_eval, false, false);
+  sculpt_update_object(depsgraph, ob_orig, me_eval, false, false, false);
 }
 
-void BKE_sculpt_update_object_for_edit(Depsgraph *depsgraph,
-                                       Object *ob_orig,
-                                       bool need_pmap,
-                                       bool need_mask)
+void BKE_sculpt_update_object_for_edit(
+    Depsgraph *depsgraph, Object *ob_orig, bool need_pmap, bool need_mask, bool need_colors)
 {
   /* Update from sculpt operators and undo, to update sculpt session
    * and PBVH after edits. */
@@ -1679,7 +1692,7 @@ void BKE_sculpt_update_object_for_edit(Depsgraph *depsgraph,
 
   BLI_assert(ob_orig == DEG_get_original_object(ob_orig));
 
-  sculpt_update_object(depsgraph, ob_orig, me_eval, need_pmap, need_mask);
+  sculpt_update_object(depsgraph, ob_orig, me_eval, need_pmap, need_mask, need_colors);
 }
 
 int BKE_sculpt_mask_layers_ensure(Object *ob, MultiresModifierData *mmd)