1 files changed, 106 insertions, 0 deletions
diff --git a/source/blender/blenkernel/intern/multires_versioning.c b/source/blender/blenkernel/intern/multires_versioning.c
new file mode 100644
index 00000000000..4c0d7165cd0
--- /dev/null
+++ b/source/blender/blenkernel/intern/multires_versioning.c
@@ -0,0 +1,106 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2020 by Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup bke
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_mesh_types.h"
+#include "DNA_modifier_types.h"
+#include "DNA_object_types.h"
+
+#include "BKE_subdiv.h"
+#include "BKE_subdiv_eval.h"
+
+#include "multires_reshape.h"
+#include "opensubdiv_converter_capi.h"
+#include "subdiv_converter.h"
+
+static float simple_to_catmull_clark_get_edge_sharpness(
+    const OpenSubdiv_Converter *UNUSED(converter), int UNUSED(manifold_edge_index))
+{
+  return 10.0f;
+}
+
+static bool simple_to_catmull_clark_is_infinite_sharp_vertex(
+    const OpenSubdiv_Converter *UNUSED(converter), int UNUSED(manifold_vertex_index))
+{
+  return true;
+}
+
+static Subdiv *subdiv_for_simple_to_catmull_clark(Object *object, MultiresModifierData *mmd)
+{
+  SubdivSettings subdiv_settings;
+  BKE_multires_subdiv_settings_init(&subdiv_settings, mmd);
+
+  Mesh *base_mesh = object->data;
+
+  OpenSubdiv_Converter converter;
+  BKE_subdiv_converter_init_for_mesh(&converter, &subdiv_settings, base_mesh);
+  converter.getEdgeSharpness = simple_to_catmull_clark_get_edge_sharpness;
+  converter.isInfiniteSharpVertex = simple_to_catmull_clark_is_infinite_sharp_vertex;
+
+  Subdiv *subdiv = BKE_subdiv_new_from_converter(&subdiv_settings, &converter);
+  BKE_subdiv_converter_free(&converter);
+
+  if (!BKE_subdiv_eval_begin_from_mesh(subdiv, base_mesh, NULL)) {
+    BKE_subdiv_free(subdiv);
+    return NULL;
+  }
+
+  return subdiv;
+}
+
+void multires_do_versions_simple_to_catmull_clark(Object *object, MultiresModifierData *mmd)
+{
+  const Mesh *base_mesh = object->data;
+  if (base_mesh->totloop == 0) {
+    return;
+  }
+
+  /* Store the grids displacement in object space against the simple limit surface. */
+  {
+    Subdiv *subdiv = subdiv_for_simple_to_catmull_clark(object, mmd);
+    MultiresReshapeContext reshape_context;
+    if (!multires_reshape_context_create_from_subdiv(
+            &reshape_context, object, mmd, subdiv, mmd->totlvl)) {
+      BKE_subdiv_free(subdiv);
+      return;
+    }
+
+    multires_reshape_store_original_grids(&reshape_context);
+    multires_reshape_assign_final_coords_from_mdisps(&reshape_context);
+    multires_reshape_context_free(&reshape_context);
+
+    BKE_subdiv_free(subdiv);
+  }
+
+  /* Calculate the new tangent displacement against the new Catmull-Clark limit surface. */
+  {
+    MultiresReshapeContext reshape_context;
+    if (!multires_reshape_context_create_from_modifier(
+            &reshape_context, object, mmd, mmd->totlvl)) {
+      return;
+    }
+    multires_reshape_object_grids_to_tangent_displacement(&reshape_context);
+    multires_reshape_context_free(&reshape_context);
+  }
+}