Multires: Initial Face Sets support

This implements the Sculpt Mode API functions needed for Face Sets and
visibility management for PBVH_GRIDS. No major changes were needed in
the operators and the sculpt mode code. This implementation stores the
face sets in the base mesh, so faces created in higher subdivision
levels can't be modified individually. Also, we are not checking for
multiple face sets per vertex (that can be added in the future), so
relax tools don't work yet. The rest of the features (paint, undo,
visibility operators..) work as expected.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D7168

2 files changed, 79 insertions, 46 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index 6ccd197c908..50b8c9a9677 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -248,7 +248,8 @@ static void SCULPT_face_set_visibility_set(SculptSession *ss, int face_set, bool
 {
   switch (BKE_pbvh_type(ss->pbvh)) {
     case PBVH_FACES:
-      for (int i = 0; i < ss->totpoly; i++) {
+    case PBVH_GRIDS:
+      for (int i = 0; i < ss->totfaces; i++) {
         if (abs(ss->face_sets[i]) == face_set) {
           if (visible) {
             ss->face_sets[i] = abs(ss->face_sets[i]);
@@ -261,8 +262,6 @@ static void SCULPT_face_set_visibility_set(SculptSession *ss, int face_set, bool
       break;
     case PBVH_BMESH:
       break;
-    case PBVH_GRIDS:
-      break;
   }
 }
 
@@ -270,14 +269,13 @@ static void SCULPT_face_sets_visibility_invert(SculptSession *ss)
 {
   switch (BKE_pbvh_type(ss->pbvh)) {
     case PBVH_FACES:
-      for (int i = 0; i < ss->totpoly; i++) {
+    case PBVH_GRIDS:
+      for (int i = 0; i < ss->totfaces; i++) {
         ss->face_sets[i] *= -1;
       }
       break;
     case PBVH_BMESH:
       break;
-    case PBVH_GRIDS:
-      break;
   }
 }
 
@@ -285,7 +283,8 @@ static void SCULPT_face_sets_visibility_all_set(SculptSession *ss, bool visible)
 {
   switch (BKE_pbvh_type(ss->pbvh)) {
     case PBVH_FACES:
-      for (int i = 0; i < ss->totpoly; i++) {
+    case PBVH_GRIDS:
+      for (int i = 0; i < ss->totfaces; i++) {
 
         /* This can run on geometry without a face set assigned, so its ID sign can't be changed to
          * modify the visibility. Force that geometry to the ID 1 to enable changing the visibility
@@ -304,8 +303,6 @@ static void SCULPT_face_sets_visibility_all_set(SculptSession *ss, bool visible)
       break;
     case PBVH_BMESH:
       break;
-    case PBVH_GRIDS:
-      break;
   }
 }
 
@@ -343,8 +340,12 @@ static bool SCULPT_vertex_all_face_sets_visible_get(SculptSession *ss, int index
     }
     case PBVH_BMESH:
       return true;
-    case PBVH_GRIDS:
-      return true;
+    case PBVH_GRIDS: {
+      const CCGKey *key = BKE_pbvh_get_grid_key(ss->pbvh);
+      const int grid_index = index / key->grid_area;
+      const int face_index = BKE_subdiv_cgg_grid_to_face_index(ss->subdiv_ccg, grid_index);
+      return ss->face_sets[face_index] > 0;
+    }
   }
   return true;
 }
@@ -362,8 +363,15 @@ static void SCULPT_vertex_face_set_set(SculptSession *ss, int index, int face_se
     } break;
     case PBVH_BMESH:
       break;
-    case PBVH_GRIDS:
-      break;
+    case PBVH_GRIDS: {
+      const CCGKey *key = BKE_pbvh_get_grid_key(ss->pbvh);
+      const int grid_index = index / key->grid_area;
+      const int face_index = BKE_subdiv_cgg_grid_to_face_index(ss->subdiv_ccg, grid_index);
+      if (ss->face_sets[face_index] > 0) {
+        ss->face_sets[face_index] = abs(face_set);
+      }
+
+    } break;
   }
 }
 
@@ -382,8 +390,12 @@ int SCULPT_vertex_face_set_get(SculptSession *ss, int index)
     }
     case PBVH_BMESH:
       return 0;
-    case PBVH_GRIDS:
-      return 0;
+    case PBVH_GRIDS: {
+      const CCGKey *key = BKE_pbvh_get_grid_key(ss->pbvh);
+      const int grid_index = index / key->grid_area;
+      const int face_index = BKE_subdiv_cgg_grid_to_face_index(ss->subdiv_ccg, grid_index);
+      return ss->face_sets[face_index];
+    }
   }
   return 0;
 }
@@ -402,8 +414,12 @@ bool SCULPT_vertex_has_face_set(SculptSession *ss, int index, int face_set)
     }
     case PBVH_BMESH:
       return true;
-    case PBVH_GRIDS:
-      return true;
+    case PBVH_GRIDS: {
+      const CCGKey *key = BKE_pbvh_get_grid_key(ss->pbvh);
+      const int grid_index = index / key->grid_area;
+      const int face_index = BKE_subdiv_cgg_grid_to_face_index(ss->subdiv_ccg, grid_index);
+      return ss->face_sets[face_index] == face_set;
+    }
   }
   return true;
 }
@@ -415,8 +431,17 @@ static void sculpt_visibility_sync_face_sets_to_vertex(SculptSession *ss, int in
 
 void SCULPT_visibility_sync_all_face_sets_to_vertices(SculptSession *ss)
 {
-  for (int i = 0; i < ss->totvert; i++) {
-    sculpt_visibility_sync_face_sets_to_vertex(ss, i);
+  switch (BKE_pbvh_type(ss->pbvh)) {
+    case PBVH_FACES: {
+      for (int i = 0; i < ss->totvert; i++) {
+        sculpt_visibility_sync_face_sets_to_vertex(ss, i);
+      }
+    }
+    case PBVH_GRIDS: {
+      BKE_pbvh_sync_face_sets_to_grids(ss->pbvh);
+    }
+    case PBVH_BMESH:
+      break;
   }
 }
 
@@ -439,7 +464,7 @@ static void UNUSED_FUNCTION(sculpt_visibility_sync_vertex_to_face_sets)(SculptSe
 void SCULPT_visibility_sync_all_vertex_to_face_sets(SculptSession *ss)
 {
   if (BKE_pbvh_type(ss->pbvh) == PBVH_FACES) {
-    for (int i = 0; i < ss->totpoly; i++) {
+    for (int i = 0; i < ss->totfaces; i++) {
       MPoly *poly = &ss->mpoly[i];
       bool poly_visible = true;
       for (int l = 0; l < poly->totloop; l++) {
@@ -479,7 +504,7 @@ bool SCULPT_vertex_has_unique_face_set(SculptSession *ss, int index)
     case PBVH_BMESH:
       return false;
     case PBVH_GRIDS:
-      return false;
+      return true;
   }
   return false;
 }
@@ -487,9 +512,10 @@ bool SCULPT_vertex_has_unique_face_set(SculptSession *ss, int index)
 static int SCULPT_face_set_next_available_get(SculptSession *ss)
 {
   switch (BKE_pbvh_type(ss->pbvh)) {
-    case PBVH_FACES: {
+    case PBVH_FACES:
+    case PBVH_GRIDS: {
       int next_face_set = 0;
-      for (int i = 0; i < ss->totpoly; i++) {
+      for (int i = 0; i < ss->totfaces; i++) {
         if (abs(ss->face_sets[i]) > next_face_set) {
           next_face_set = abs(ss->face_sets[i]);
         }
@@ -499,8 +525,6 @@ static int SCULPT_face_set_next_available_get(SculptSession *ss)
     }
     case PBVH_BMESH:
       return 0;
-    case PBVH_GRIDS:
-      return 0;
   }
   return 0;
 }
@@ -10286,7 +10310,7 @@ static void sculpt_mask_expand_cancel(bContext *C, wmOperator *op)
   for (int n = 0; n < ss->filter_cache->totnode; n++) {
     PBVHNode *node = ss->filter_cache->nodes[n];
     if (create_face_set) {
-      for (int i = 0; i < ss->totpoly; i++) {
+      for (int i = 0; i < ss->totfaces; i++) {
         ss->face_sets[i] = ss->filter_cache->prev_face_set[i];
       }
     }
@@ -10492,7 +10516,7 @@ static int sculpt_mask_expand_modal(bContext *C, wmOperator *op, const wmEvent *
   if (mask_expand_update_it < ss->filter_cache->mask_update_last_it) {
 
     if (create_face_set) {
-      for (int i = 0; i < ss->totpoly; i++) {
+      for (int i = 0; i < ss->totfaces; i++) {
         ss->face_sets[i] = ss->filter_cache->prev_face_set[i];
       }
     }
@@ -10619,8 +10643,8 @@ static int sculpt_mask_expand_invoke(bContext *C, wmOperator *op, const wmEvent
   }
 
   if (create_face_set) {
-    ss->filter_cache->prev_face_set = MEM_callocN(sizeof(float) * ss->totpoly, "prev face mask");
-    for (int i = 0; i < ss->totpoly; i++) {
+    ss->filter_cache->prev_face_set = MEM_callocN(sizeof(float) * ss->totfaces, "prev face mask");
+    for (int i = 0; i < ss->totfaces; i++) {
       ss->filter_cache->prev_face_set[i] = ss->face_sets[i];
     }
     ss->filter_cache->new_face_set = SCULPT_face_set_next_available_get(ss);
@@ -11172,8 +11196,8 @@ static int sculpt_face_set_create_invoke(bContext *C, wmOperator *op, const wmEv
 
   const int mode = RNA_enum_get(op->ptr, "mode");
 
-  /* Dyntopo and Multires not supported for now. */
-  if (BKE_pbvh_type(ss->pbvh) != PBVH_FACES) {
+  /* Dyntopo not suported. */
+  if (BKE_pbvh_type(ss->pbvh) == PBVH_BMESH) {
     return OPERATOR_CANCELLED;
   }
 
@@ -11514,8 +11538,8 @@ static int sculpt_face_set_init_invoke(bContext *C, wmOperator *op, const wmEven
 
   const int mode = RNA_enum_get(op->ptr, "mode");
 
-  /* Dyntopo and Multires not supported for now. */
-  if (BKE_pbvh_type(ss->pbvh) != PBVH_FACES) {
+  /* Dyntopo not supported. */
+  if (BKE_pbvh_type(ss->pbvh) == PBVH_BMESH) {
     return OPERATOR_CANCELLED;
   }
 
@@ -11673,8 +11697,8 @@ static int sculpt_face_sets_change_visibility_invoke(bContext *C,
   ARegion *region = CTX_wm_region(C);
   Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
 
-  /* Dyntopo and Multires not supported for now. */
-  if (BKE_pbvh_type(ss->pbvh) != PBVH_FACES) {
+  /* Dyntopo not supported. */
+  if (BKE_pbvh_type(ss->pbvh) == PBVH_BMESH) {
     return OPERATOR_CANCELLED;
   }
 
@@ -11714,7 +11738,7 @@ static int sculpt_face_sets_change_visibility_invoke(bContext *C,
       }
     }
 
-    for (int i = 0; i < ss->totpoly; i++) {
+    for (int i = 0; i < ss->totfaces; i++) {
       if (ss->face_sets[i] <= 0) {
         hidden_vertex = true;
         break;
@@ -11834,8 +11858,9 @@ static int sculpt_face_sets_randomize_colors_invoke(bContext *C,
 
   mesh->face_sets_color_seed += 1;
   if (ss->face_sets) {
-    const int random_index = clamp_i(
-        ss->totpoly * BLI_hash_int_01(mesh->face_sets_color_seed), 0, max_ii(0, ss->totpoly - 1));
+    const int random_index = clamp_i(ss->totfaces * BLI_hash_int_01(mesh->face_sets_color_seed),
+                                     0,
+                                     max_ii(0, ss->totfaces - 1));
     mesh->face_sets_color_default = ss->face_sets[random_index];
   }
   BKE_pbvh_face_sets_color_set(pbvh, mesh->face_sets_color_seed, mesh->face_sets_color_default);
diff --git a/source/blender/editors/sculpt_paint/sculpt_undo.c b/source/blender/editors/sculpt_paint/sculpt_undo.c
index af404c64fb0..5233ce8d257 100644
--- a/source/blender/editors/sculpt_paint/sculpt_undo.c
+++ b/source/blender/editors/sculpt_paint/sculpt_undo.c
@@ -48,6 +48,7 @@
 #include "BKE_main.h"
 #include "BKE_mesh.h"
 #include "BKE_multires.h"
+#include "BKE_object.h"
 #include "BKE_paint.h"
 #include "BKE_scene.h"
 #include "BKE_subdiv_ccg.h"
@@ -335,8 +336,11 @@ static bool sculpt_undo_restore_face_sets(bContext *C, SculptUndoNode *unode)
 {
   ViewLayer *view_layer = CTX_data_view_layer(C);
   Object *ob = OBACT(view_layer);
-  SculptSession *ss = ob->sculpt;
-  memcpy(ss->face_sets, unode->face_sets, ss->totpoly * sizeof(int));
+  Mesh *me = BKE_object_get_original_mesh(ob);
+  int *face_sets = CustomData_get_layer(&me->pdata, CD_SCULPT_FACE_SETS);
+  for (int i = 0; i < me->totpoly; i++) {
+    face_sets[i] = unode->face_sets[i];
+  }
   return false;
 }
 
@@ -542,7 +546,6 @@ static void sculpt_undo_restore_list(bContext *C, Depsgraph *depsgraph, ListBase
       return;
     }
     else if (unode->type == SCULPT_UNDO_FACE_SETS) {
-
       sculpt_undo_restore_face_sets(C, unode);
 
       rebuild = true;
@@ -551,14 +554,15 @@ static void sculpt_undo_restore_list(bContext *C, Depsgraph *depsgraph, ListBase
       BKE_sculpt_update_object_for_edit(depsgraph, ob, true, need_mask);
 
       SCULPT_visibility_sync_all_face_sets_to_vertices(ss);
+
       BKE_pbvh_update_vertex_data(ss->pbvh, PBVH_UpdateVisibility);
 
       if (BKE_pbvh_type(ss->pbvh) == PBVH_FACES) {
         BKE_mesh_flush_hidden_from_verts(ob->data);
       }
 
+      DEG_id_tag_update(&ob->id, ID_RECALC_SHADING);
       if (!BKE_sculptsession_use_pbvh_draw(ob, v3d)) {
-        DEG_id_tag_update(&ob->id, ID_RECALC_SHADING);
         DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
       }
 
@@ -983,8 +987,6 @@ static SculptUndoNode *sculpt_undo_geometry_push(Object *ob, SculptUndoType type
 static SculptUndoNode *sculpt_undo_face_sets_push(Object *ob, SculptUndoType type)
 {
   UndoSculpt *usculpt = sculpt_undo_get_nodes();
-  SculptSession *ss = ob->sculpt;
-
   SculptUndoNode *unode = usculpt->nodes.first;
 
   unode = MEM_callocN(sizeof(*unode), __func__);
@@ -993,8 +995,14 @@ static SculptUndoNode *sculpt_undo_face_sets_push(Object *ob, SculptUndoType typ
   unode->type = type;
   unode->applied = true;
 
-  unode->face_sets = MEM_callocN(ss->totpoly * sizeof(int), "sculpt face sets");
-  memcpy(unode->face_sets, ss->face_sets, ss->totpoly * sizeof(int));
+  Mesh *me = BKE_object_get_original_mesh(ob);
+
+  unode->face_sets = MEM_callocN(me->totpoly * sizeof(int), "sculpt face sets");
+
+  int *face_sets = CustomData_get_layer(&me->pdata, CD_SCULPT_FACE_SETS);
+  for (int i = 0; i < me->totpoly; i++) {
+    unode->face_sets[i] = face_sets[i];
+  }
 
   BLI_addtail(&usculpt->nodes, unode);