Fix T101925: sculpt color painting not updating with Cycles viewport render

* External engines do not use the PBVH and need slower depsgraph updates.
* Final depsgraph tag after stroke finishes was missing for sculpt color
  painting, caused missing updates for other viewports as well as any
  modifiers or nodes on other objects using the colors.

2 files changed, 27 insertions, 25 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index 95192114429..34d0158f187 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -1121,8 +1121,8 @@ void SCULPT_tag_update_overlays(bContext *C)
 
   DEG_id_tag_update(&ob->id, ID_RECALC_SHADING);
 
-  View3D *v3d = CTX_wm_view3d(C);
-  if (!BKE_sculptsession_use_pbvh_draw(ob, v3d)) {
+  RegionView3D *rv3d = CTX_wm_region_view3d(C);
+  if (!BKE_sculptsession_use_pbvh_draw(ob, rv3d)) {
     DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
   }
 }
@@ -4813,12 +4813,12 @@ static bool sculpt_needs_connectivity_info(const Sculpt *sd,
 void SCULPT_stroke_modifiers_check(const bContext *C, Object *ob, const Brush *brush)
 {
   SculptSession *ss = ob->sculpt;
-  View3D *v3d = CTX_wm_view3d(C);
+  RegionView3D *rv3d = CTX_wm_region_view3d(C);
   Sculpt *sd = CTX_data_tool_settings(C)->sculpt;
 
   bool need_pmap = sculpt_needs_connectivity_info(sd, brush, ss, 0);
   if (ss->shapekey_active || ss->deform_modifiers_active ||
-      (!BKE_sculptsession_use_pbvh_draw(ob, v3d) && need_pmap)) {
+      (!BKE_sculptsession_use_pbvh_draw(ob, rv3d) && need_pmap)) {
     Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
     BKE_sculpt_update_object_for_edit(
         depsgraph, ob, need_pmap, false, SCULPT_tool_is_paint(brush->sculpt_tool));
@@ -5249,7 +5249,6 @@ void SCULPT_flush_update_step(bContext *C, SculptUpdateType update_flags)
   SculptSession *ss = ob->sculpt;
   ARegion *region = CTX_wm_region(C);
   MultiresModifierData *mmd = ss->multires.modifier;
-  View3D *v3d = CTX_wm_view3d(C);
   RegionView3D *rv3d = CTX_wm_region_view3d(C);
 
   if (rv3d) {
@@ -5274,7 +5273,7 @@ void SCULPT_flush_update_step(bContext *C, SculptUpdateType update_flags)
 
   /* Only current viewport matters, slower update for all viewports will
    * be done in sculpt_flush_update_done. */
-  if (!BKE_sculptsession_use_pbvh_draw(ob, v3d)) {
+  if (!BKE_sculptsession_use_pbvh_draw(ob, rv3d)) {
     /* Slow update with full dependency graph update and all that comes with it.
      * Needed when there are modifiers or full shading in the 3D viewport. */
     DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
@@ -5316,16 +5315,15 @@ void SCULPT_flush_update_done(const bContext *C, Object *ob, SculptUpdateType up
   /* After we are done drawing the stroke, check if we need to do a more
    * expensive depsgraph tag to update geometry. */
   wmWindowManager *wm = CTX_wm_manager(C);
-  View3D *current_v3d = CTX_wm_view3d(C);
-  RegionView3D *rv3d = CTX_wm_region_view3d(C);
+  RegionView3D *current_rv3d = CTX_wm_region_view3d(C);
   SculptSession *ss = ob->sculpt;
   Mesh *mesh = ob->data;
 
   /* Always needed for linked duplicates. */
   bool need_tag = (ID_REAL_USERS(&mesh->id) > 1);
 
-  if (rv3d) {
-    rv3d->rflag &= ~RV3D_PAINTING;
+  if (current_rv3d) {
+    current_rv3d->rflag &= ~RV3D_PAINTING;
   }
 
   LISTBASE_FOREACH (wmWindow *, win, &wm->windows) {
@@ -5335,16 +5333,17 @@ void SCULPT_flush_update_done(const bContext *C, Object *ob, SculptUpdateType up
       if (sl->spacetype != SPACE_VIEW3D) {
         continue;
       }
-      View3D *v3d = (View3D *)sl;
-      if (v3d != current_v3d) {
-        need_tag |= !BKE_sculptsession_use_pbvh_draw(ob, v3d);
-      }
 
       /* Tag all 3D viewports for redraw now that we are done. Others
        * viewports did not get a full redraw, and anti-aliasing for the
        * current viewport was deactivated. */
       LISTBASE_FOREACH (ARegion *, region, &area->regionbase) {
         if (region->regiontype == RGN_TYPE_WINDOW) {
+          RegionView3D *rv3d = region->regiondata;
+          if (rv3d != current_rv3d) {
+            need_tag |= !BKE_sculptsession_use_pbvh_draw(ob, rv3d);
+          }
+
           ED_region_tag_redraw(region);
         }
       }
@@ -5378,15 +5377,17 @@ void SCULPT_flush_update_done(const bContext *C, Object *ob, SculptUpdateType up
 
   BKE_sculpt_attributes_destroy_temporary_stroke(ob);
 
-  if (BKE_pbvh_type(ss->pbvh) == PBVH_BMESH) {
-    BKE_pbvh_bmesh_after_stroke(ss->pbvh);
-  }
+  if (update_flags & SCULPT_UPDATE_COORDS) {
+    if (BKE_pbvh_type(ss->pbvh) == PBVH_BMESH) {
+      BKE_pbvh_bmesh_after_stroke(ss->pbvh);
+    }
 
-  /* Optimization: if there is locked key and active modifiers present in */
-  /* the stack, keyblock is updating at each step. otherwise we could update */
-  /* keyblock only when stroke is finished. */
-  if (ss->shapekey_active && !ss->deform_modifiers_active) {
-    sculpt_update_keyblock(ob);
+    /* Optimization: if there is locked key and active modifiers present in */
+    /* the stack, keyblock is updating at each step. otherwise we could update */
+    /* keyblock only when stroke is finished. */
+    if (ss->shapekey_active && !ss->deform_modifiers_active) {
+      sculpt_update_keyblock(ob);
+    }
   }
 
   if (need_tag) {
@@ -5625,6 +5626,7 @@ static void sculpt_stroke_done(const bContext *C, struct PaintStroke *UNUSED(str
     }
     else {
       BKE_sculpt_attributes_destroy_temporary_stroke(ob);
+      SCULPT_flush_update_done(C, ob, SCULPT_UPDATE_COLOR);
     }
   }
   else {
diff --git a/source/blender/editors/sculpt_paint/sculpt_undo.c b/source/blender/editors/sculpt_paint/sculpt_undo.c
index 13e3dd64521..eb92c865f18 100644
--- a/source/blender/editors/sculpt_paint/sculpt_undo.c
+++ b/source/blender/editors/sculpt_paint/sculpt_undo.c
@@ -857,7 +857,7 @@ static void sculpt_undo_restore_list(bContext *C, Depsgraph *depsgraph, ListBase
 {
   Scene *scene = CTX_data_scene(C);
   ViewLayer *view_layer = CTX_data_view_layer(C);
-  View3D *v3d = CTX_wm_view3d(C);
+  RegionView3D *rv3d = CTX_wm_region_view3d(C);
   BKE_view_layer_synced_ensure(scene, view_layer);
   Object *ob = BKE_view_layer_active_object_get(view_layer);
   SculptSession *ss = ob->sculpt;
@@ -911,7 +911,7 @@ static void sculpt_undo_restore_list(bContext *C, Depsgraph *depsgraph, ListBase
       }
 
       DEG_id_tag_update(&ob->id, ID_RECALC_SHADING);
-      if (!BKE_sculptsession_use_pbvh_draw(ob, v3d)) {
+      if (!BKE_sculptsession_use_pbvh_draw(ob, rv3d)) {
         DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
       }
 
@@ -1070,7 +1070,7 @@ static void sculpt_undo_restore_list(bContext *C, Depsgraph *depsgraph, ListBase
       }
     }
 
-    tag_update |= ID_REAL_USERS(ob->data) > 1 || !BKE_sculptsession_use_pbvh_draw(ob, v3d) ||
+    tag_update |= ID_REAL_USERS(ob->data) > 1 || !BKE_sculptsession_use_pbvh_draw(ob, rv3d) ||
                   ss->shapekey_active || ss->deform_modifiers_active;
 
     if (tag_update) {