Fix T62941 Subdivision Modifier Showing all face dots

Previously in 2.79 we were using a specialized drawing using derivedMesh.

Now the subsurf modifier tag each center vertex as facedot and let the
DRWManager pick it up.

Some modifiers (deforming ones) do not clear the tag so we can use this
technique even if there is deforming modifiers after subsurf modifiers.

1 files changed, 48 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/mesh_iterators.c b/source/blender/blenkernel/intern/mesh_iterators.c
index df6517066b8..f2ed9456b11 100644
--- a/source/blender/blenkernel/intern/mesh_iterators.c
+++ b/source/blender/blenkernel/intern/mesh_iterators.c
@@ -180,6 +180,54 @@ void BKE_mesh_foreach_mapped_face_center(
   }
 }
 
+/* Copied from cdDM_foreachMappedFaceCenter */
+void BKE_mesh_foreach_mapped_subdiv_face_center(
+    Mesh *mesh,
+    void (*func)(void *userData, int index, const float cent[3], const float no[3]),
+    void *userData,
+    MeshForeachFlag flag)
+{
+  const MPoly *mp = mesh->mpoly;
+  const MLoop *ml;
+  const MVert *mv;
+  float _no_buf[3];
+  float *no = (flag & MESH_FOREACH_USE_NORMAL) ? _no_buf : NULL;
+  const int *index = CustomData_get_layer(&mesh->pdata, CD_ORIGINDEX);
+
+  if (index) {
+    for (int i = 0; i < mesh->totpoly; i++, mp++) {
+      const int orig = *index++;
+      if (orig == ORIGINDEX_NONE) {
+        continue;
+      }
+      ml = &mesh->mloop[mp->loopstart];
+      for (int j = 0; j < mp->totloop; j++, ml++) {
+        mv = &mesh->mvert[ml->v];
+        if (mv->flag & ME_VERT_FACEDOT) {
+          if (flag & MESH_FOREACH_USE_NORMAL) {
+            normal_short_to_float_v3(no, mv->no);
+          }
+          func(userData, orig, mv->co, no);
+        }
+      }
+    }
+  }
+  else {
+    for (int i = 0; i < mesh->totpoly; i++, mp++) {
+      ml = &mesh->mloop[mp->loopstart];
+      for (int j = 0; j < mp->totloop; j++, ml++) {
+        mv = &mesh->mvert[ml->v];
+        if (mv->flag & ME_VERT_FACEDOT) {
+          if (flag & MESH_FOREACH_USE_NORMAL) {
+            normal_short_to_float_v3(no, mv->no);
+          }
+          func(userData, i, mv->co, no);
+        }
+      }
+    }
+  }
+}
+
 /* Helpers based on above foreach loopers> */
 
 typedef struct MappedVCosData {