Fix T81511: Loop-cut overlay doesn't follow deformed cage

With constructive + deform modifiers, loop-cut visualization
wasn't following the displayed mesh.

This now gets the coordinates from the cage when available.

1 files changed, 29 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/editmesh.c b/source/blender/blenkernel/intern/editmesh.c
index 1a5b7685c0e..c5a4b48aed8 100644
--- a/source/blender/blenkernel/intern/editmesh.c
+++ b/source/blender/blenkernel/intern/editmesh.c
@@ -36,6 +36,7 @@
 #include "BKE_lib_id.h"
 #include "BKE_mesh.h"
 #include "BKE_mesh_iterators.h"
+// #include "BKE_jesh_runtime.h"
 #include "BKE_mesh_wrapper.h"
 #include "BKE_object.h"
 
@@ -228,6 +229,34 @@ float (*BKE_editmesh_vert_coords_alloc(struct Depsgraph *depsgraph,
   return cos_cage;
 }
 
+const float (*BKE_editmesh_vert_coords_when_deformed(struct Depsgraph *depsgraph,
+                                                     BMEditMesh *em,
+                                                     struct Scene *scene,
+                                                     Object *ob,
+                                                     int *r_vert_len,
+                                                     bool *r_is_alloc))[3]
+{
+  const float(*coords)[3] = NULL;
+  *r_is_alloc = false;
+
+  Mesh *me = ob->data;
+
+  if ((me->runtime.edit_data != NULL) && (me->runtime.edit_data->vertexCos != NULL)) {
+    /* Deformed, and we have deformed coords already. */
+    coords = me->runtime.edit_data->vertexCos;
+  }
+  else if ((em->mesh_eval_final != NULL) &&
+           (em->mesh_eval_final->runtime.wrapper_type == ME_WRAPPER_TYPE_BMESH)) {
+    /* If this is an edit-mesh type, leave NULL as we can use the vertex coords. . */
+  }
+  else {
+    /* Constructive modifiers have been used, we need to allocate coordinates. */
+    *r_is_alloc = true;
+    coords = BKE_editmesh_vert_coords_alloc(depsgraph, em, scene, ob, r_vert_len);
+  }
+  return coords;
+}
+
 float (*BKE_editmesh_vert_coords_alloc_orco(BMEditMesh *em, int *r_vert_len))[3]
 {
   return BM_mesh_vert_coords_alloc(em->bm, r_vert_len);