Sculpt Undo: Refactor Geometry undo nodes

Made it so there is a single UNDO node in the list which has
both original and modified mesh state.

Makes it easier to achieve "interleaved" undo nodes stored in
the undo step (as opposite of either storing geometry or other
data).

Should be no functional changes, just preparing for an upcoming
work to support undo of operation like Apply Base.

Differential Revision: https://developer.blender.org/D7290

1 files changed, 120 insertions, 82 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt_undo.c b/source/blender/editors/sculpt_paint/sculpt_undo.c
index 5233ce8d257..67ef82aeaaf 100644
--- a/source/blender/editors/sculpt_paint/sculpt_undo.c
+++ b/source/blender/editors/sculpt_paint/sculpt_undo.c
@@ -447,30 +447,82 @@ static void sculpt_undo_bmesh_restore_end(bContext *C,
   }
 }
 
-static void sculpt_undo_geometry_restore(SculptUndoNode *unode, Object *ob)
+static void sculpt_undo_geometry_store_data(SculptUndoNodeGeometry *geometry, Object *object)
 {
-  Mesh *me;
-  sculpt_pbvh_clear(ob);
-  me = ob->data;
-  CustomData_free(&me->vdata, me->totvert);
-  CustomData_free(&me->edata, me->totedge);
-  CustomData_free(&me->fdata, me->totface);
-  CustomData_free(&me->ldata, me->totloop);
-  CustomData_free(&me->pdata, me->totpoly);
-  me->totvert = unode->geom_totvert;
-  me->totedge = unode->geom_totedge;
-  me->totloop = unode->geom_totloop;
-  me->totpoly = unode->geom_totpoly;
-  me->totface = 0;
+  Mesh *mesh = object->data;
+
+  BLI_assert(!geometry->is_initialized);
+  geometry->is_initialized = true;
+
+  CustomData_copy(&mesh->vdata, &geometry->vdata, CD_MASK_MESH.vmask, CD_DUPLICATE, mesh->totvert);
+  CustomData_copy(&mesh->edata, &geometry->edata, CD_MASK_MESH.emask, CD_DUPLICATE, mesh->totedge);
+  CustomData_copy(&mesh->ldata, &geometry->ldata, CD_MASK_MESH.lmask, CD_DUPLICATE, mesh->totloop);
+  CustomData_copy(&mesh->pdata, &geometry->pdata, CD_MASK_MESH.pmask, CD_DUPLICATE, mesh->totpoly);
+
+  geometry->totvert = mesh->totvert;
+  geometry->totedge = mesh->totedge;
+  geometry->totloop = mesh->totloop;
+  geometry->totpoly = mesh->totpoly;
+}
+
+static void sculpt_undo_geometry_restore_data(SculptUndoNodeGeometry *geometry, Object *object)
+{
+  Mesh *mesh = object->data;
+
+  BLI_assert(geometry->is_initialized);
+
+  CustomData_free(&mesh->vdata, mesh->totvert);
+  CustomData_free(&mesh->edata, mesh->totedge);
+  CustomData_free(&mesh->fdata, mesh->totface);
+  CustomData_free(&mesh->ldata, mesh->totloop);
+  CustomData_free(&mesh->pdata, mesh->totpoly);
+
+  mesh->totvert = geometry->totvert;
+  mesh->totedge = geometry->totedge;
+  mesh->totloop = geometry->totloop;
+  mesh->totpoly = geometry->totpoly;
+  mesh->totface = 0;
+
   CustomData_copy(
-      &unode->geom_vdata, &me->vdata, CD_MASK_MESH.vmask, CD_DUPLICATE, unode->geom_totvert);
+      &geometry->vdata, &mesh->vdata, CD_MASK_MESH.vmask, CD_DUPLICATE, geometry->totvert);
   CustomData_copy(
-      &unode->geom_edata, &me->edata, CD_MASK_MESH.emask, CD_DUPLICATE, unode->geom_totedge);
+      &geometry->edata, &mesh->edata, CD_MASK_MESH.emask, CD_DUPLICATE, geometry->totedge);
   CustomData_copy(
-      &unode->geom_ldata, &me->ldata, CD_MASK_MESH.lmask, CD_DUPLICATE, unode->geom_totloop);
+      &geometry->ldata, &mesh->ldata, CD_MASK_MESH.lmask, CD_DUPLICATE, geometry->totloop);
   CustomData_copy(
-      &unode->geom_pdata, &me->pdata, CD_MASK_MESH.pmask, CD_DUPLICATE, unode->geom_totpoly);
-  BKE_mesh_update_customdata_pointers(me, false);
+      &geometry->pdata, &mesh->pdata, CD_MASK_MESH.pmask, CD_DUPLICATE, geometry->totpoly);
+
+  BKE_mesh_update_customdata_pointers(mesh, false);
+}
+
+static void sculpt_undo_geometry_free_data(SculptUndoNodeGeometry *geometry)
+{
+  if (geometry->totvert) {
+    CustomData_free(&geometry->vdata, geometry->totvert);
+  }
+  if (geometry->totedge) {
+    CustomData_free(&geometry->edata, geometry->totedge);
+  }
+  if (geometry->totloop) {
+    CustomData_free(&geometry->ldata, geometry->totloop);
+  }
+  if (geometry->totpoly) {
+    CustomData_free(&geometry->pdata, geometry->totpoly);
+  }
+}
+
+static void sculpt_undo_geometry_restore(SculptUndoNode *unode, Object *object)
+{
+  sculpt_pbvh_clear(object);
+
+  if (unode->applied) {
+    sculpt_undo_geometry_restore_data(&unode->geometry_modified, object);
+    unode->applied = false;
+  }
+  else {
+    sculpt_undo_geometry_restore_data(&unode->geometry_original, object);
+    unode->applied = true;
+  }
 }
 
 /* Handle all dynamic-topology updates
@@ -532,16 +584,7 @@ static void sculpt_undo_restore_list(bContext *C, Depsgraph *depsgraph, ListBase
   if (lb->first) {
     unode = lb->first;
     if (unode->type == SCULPT_UNDO_GEOMETRY) {
-      if (unode->applied) {
-        sculpt_undo_geometry_restore(unode->next, ob);
-        unode->next->applied = true;
-        unode->applied = false;
-      }
-      else {
-        sculpt_undo_geometry_restore(unode, ob);
-        unode->next->applied = false;
-        unode->applied = true;
-      }
+      sculpt_undo_geometry_restore(unode, ob);
       BKE_sculpt_update_object_for_edit(depsgraph, ob, false, need_mask);
       return;
     }
@@ -741,18 +784,8 @@ static void sculpt_undo_free_list(ListBase *lb)
       BM_log_entry_drop(unode->bm_entry);
     }
 
-    if (unode->geom_totvert) {
-      CustomData_free(&unode->geom_vdata, unode->geom_totvert);
-    }
-    if (unode->geom_totedge) {
-      CustomData_free(&unode->geom_edata, unode->geom_totedge);
-    }
-    if (unode->geom_totloop) {
-      CustomData_free(&unode->geom_ldata, unode->geom_totloop);
-    }
-    if (unode->geom_totpoly) {
-      CustomData_free(&unode->geom_pdata, unode->geom_totpoly);
-    }
+    sculpt_undo_geometry_free_data(&unode->geometry_original);
+    sculpt_undo_geometry_free_data(&unode->geometry_modified);
 
     if (unode->face_sets) {
       MEM_freeN(unode->face_sets);
@@ -820,16 +853,43 @@ static void sculpt_undo_alloc_and_store_hidden(PBVH *pbvh, SculptUndoNode *unode
   }
 }
 
+/* Allocate node and initialize its default fields specific for the given undo type.
+ * Will also add the node to the list in the undo step. */
+static SculptUndoNode *sculpt_undo_alloc_node_type(Object *object, SculptUndoType type)
+{
+  SculptUndoNode *unode = MEM_callocN(sizeof(SculptUndoNode), "SculptUndoNode");
+  BLI_strncpy(unode->idname, object->id.name, sizeof(unode->idname));
+  unode->type = type;
+
+  UndoSculpt *usculpt = sculpt_undo_get_nodes();
+  BLI_addtail(&usculpt->nodes, unode);
+
+  return unode;
+}
+
+/* Will return first existing undo node of the given type.
+ * If such node does not exist will allocate node of this type, register it in the undo step and
+ * return it. */
+static SculptUndoNode *sculpt_undo_find_or_alloc_node_type(Object *object, SculptUndoType type)
+{
+  UndoSculpt *usculpt = sculpt_undo_get_nodes();
+
+  LISTBASE_FOREACH (SculptUndoNode *, unode, &usculpt->nodes) {
+    if (unode->type == type) {
+      return unode;
+    }
+  }
+
+  return sculpt_undo_alloc_node_type(object, type);
+}
+
 static SculptUndoNode *sculpt_undo_alloc_node(Object *ob, PBVHNode *node, SculptUndoType type)
 {
   UndoSculpt *usculpt = sculpt_undo_get_nodes();
-  SculptUndoNode *unode;
   SculptSession *ss = ob->sculpt;
   int totvert, allvert, totgrid, maxgrid, gridsize, *grids;
 
-  unode = MEM_callocN(sizeof(SculptUndoNode), "SculptUndoNode");
-  BLI_strncpy(unode->idname, ob->id.name, sizeof(unode->idname));
-  unode->type = type;
+  SculptUndoNode *unode = sculpt_undo_alloc_node_type(ob, type);
   unode->node = node;
 
   if (node) {
@@ -876,8 +936,6 @@ static SculptUndoNode *sculpt_undo_alloc_node(Object *ob, PBVHNode *node, Sculpt
       break;
   }
 
-  BLI_addtail(&usculpt->nodes, unode);
-
   if (maxgrid) {
     /* Multires. */
     unode->maxgrid = maxgrid;
@@ -954,32 +1012,24 @@ static void sculpt_undo_store_mask(Object *ob, SculptUndoNode *unode)
   BKE_pbvh_vertex_iter_end;
 }
 
-static SculptUndoNode *sculpt_undo_geometry_push(Object *ob, SculptUndoType type)
+static SculptUndoNodeGeometry *sculpt_undo_geometry_get(SculptUndoNode *unode)
 {
-  UndoSculpt *usculpt = sculpt_undo_get_nodes();
-  Mesh *me = ob->data;
-  bool applied;
-
-  SculptUndoNode *unode = usculpt->nodes.first;
-  /* Store the original mesh in the first node, modifications in the second. */
-  applied = unode != NULL;
+  if (!unode->geometry_original.is_initialized) {
+    return &unode->geometry_original;
+  }
 
-  unode = MEM_callocN(sizeof(*unode), __func__);
+  BLI_assert(!unode->geometry_modified.is_initialized);
 
-  BLI_strncpy(unode->idname, ob->id.name, sizeof(unode->idname));
-  unode->type = type;
-  unode->applied = applied;
+  return &unode->geometry_modified;
+}
 
-  CustomData_copy(&me->vdata, &unode->geom_vdata, CD_MASK_MESH.vmask, CD_DUPLICATE, me->totvert);
-  CustomData_copy(&me->edata, &unode->geom_edata, CD_MASK_MESH.emask, CD_DUPLICATE, me->totedge);
-  CustomData_copy(&me->ldata, &unode->geom_ldata, CD_MASK_MESH.lmask, CD_DUPLICATE, me->totloop);
-  CustomData_copy(&me->pdata, &unode->geom_pdata, CD_MASK_MESH.pmask, CD_DUPLICATE, me->totpoly);
-  unode->geom_totvert = me->totvert;
-  unode->geom_totedge = me->totedge;
-  unode->geom_totloop = me->totloop;
-  unode->geom_totpoly = me->totpoly;
+static SculptUndoNode *sculpt_undo_geometry_push(Object *object, SculptUndoType type)
+{
+  SculptUndoNode *unode = sculpt_undo_find_or_alloc_node_type(object, type);
+  unode->applied = false;
 
-  BLI_addtail(&usculpt->nodes, unode);
+  SculptUndoNodeGeometry *geometry = sculpt_undo_geometry_get(unode);
+  sculpt_undo_geometry_store_data(geometry, object);
 
   return unode;
 }
@@ -1029,25 +1079,13 @@ static SculptUndoNode *sculpt_undo_bmesh_push(Object *ob, PBVHNode *node, Sculpt
       BM_log_before_all_removed(ss->bm, ss->bm_log);
     }
     else if (type == SCULPT_UNDO_DYNTOPO_BEGIN) {
-      Mesh *me = ob->data;
-
       /* Store a copy of the mesh's current vertices, loops, and
        * polys. A full copy like this is needed because entering
        * dynamic-topology immediately does topological edits
        * (converting polys to triangles) that the BMLog can't
        * fully restore from. */
-      CustomData_copy(
-          &me->vdata, &unode->geom_vdata, CD_MASK_MESH.vmask, CD_DUPLICATE, me->totvert);
-      CustomData_copy(
-          &me->edata, &unode->geom_edata, CD_MASK_MESH.emask, CD_DUPLICATE, me->totedge);
-      CustomData_copy(
-          &me->ldata, &unode->geom_ldata, CD_MASK_MESH.lmask, CD_DUPLICATE, me->totloop);
-      CustomData_copy(
-          &me->pdata, &unode->geom_pdata, CD_MASK_MESH.pmask, CD_DUPLICATE, me->totpoly);
-      unode->geom_totvert = me->totvert;
-      unode->geom_totedge = me->totedge;
-      unode->geom_totloop = me->totloop;
-      unode->geom_totpoly = me->totpoly;
+      SculptUndoNodeGeometry *geometry = &unode->geometry_bmesh_enter;
+      sculpt_undo_geometry_store_data(geometry, ob);
 
       unode->bm_entry = BM_log_entry_add(ss->bm_log);
       BM_log_all_added(ss->bm, ss->bm_log);