1 files changed, 27 insertions, 22 deletions

diff --git a/source/blender/modifiers/intern/MOD_subsurf.c b/source/blender/modifiers/intern/MOD_subsurf.c
index e66b3fdbafb..1899faa3583 100644
--- a/source/blender/modifiers/intern/MOD_subsurf.c
+++ b/source/blender/modifiers/intern/MOD_subsurf.c
@@ -1,6 +1,4 @@
 /*
- * ***** BEGIN GPL LICENSE BLOCK *****
- *
  * 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
@@ -17,30 +15,21 @@
  *
  * The Original Code is Copyright (C) 2005 by the Blender Foundation.
  * All rights reserved.
- *
- * Contributor(s): Daniel Dunbar
- *                 Ton Roosendaal,
- *                 Ben Batt,
- *                 Brecht Van Lommel,
- *                 Campbell Barton
- *
- * ***** END GPL LICENSE BLOCK *****
- *
  */
 
-/** \file blender/modifiers/intern/MOD_subsurf.c
- *  \ingroup modifiers
+/** \file
+ * \ingroup modifiers
  */
 
 
 #include <stddef.h>
 
+#include "BLI_utildefines.h"
+
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
 #include "DNA_mesh_types.h"
 
-#include "BLI_utildefines.h"
-
 #include "BKE_cdderivedmesh.h"
 #include "BKE_scene.h"
 #include "BKE_subdiv.h"
@@ -75,6 +64,7 @@ static void copyData(const ModifierData *md, ModifierData *target, const int fla
 	modifier_copyData_generic(md, target, flag);
 
 	tsmd->emCache = tsmd->mCache = NULL;
+	tsmd->subdiv = NULL;
 }
 
 static void freeData(ModifierData *md)
@@ -89,6 +79,9 @@ static void freeData(ModifierData *md)
 		ccgSubSurf_free(smd->emCache);
 		smd->emCache = NULL;
 	}
+	if (smd->subdiv != NULL) {
+		BKE_subdiv_free(smd->subdiv);
+	}
 }
 
 static bool isDisabled(const Scene *scene, ModifierData *md, bool useRenderParams)
@@ -122,6 +115,18 @@ static void subdiv_settings_init(SubdivSettings *settings,
 	        BKE_subdiv_fvar_interpolation_from_uv_smooth(smd->uv_smooth);
 }
 
+/* Main goal of this function is to give usable subdivision surface descriptor
+ * which matches settings and topology. */
+static Subdiv *subdiv_descriptor_ensure(SubsurfModifierData *smd,
+                                        const SubdivSettings *subdiv_settings,
+                                        const Mesh *mesh)
+{
+	Subdiv *subdiv = BKE_subdiv_update_from_mesh(
+	        smd->subdiv, subdiv_settings, mesh);
+	smd->subdiv = subdiv;
+	return subdiv;
+}
+
 /* Subdivide into fully qualified mesh. */
 
 static void subdiv_mesh_settings_init(SubdivToMeshSettings *settings,
@@ -189,24 +194,24 @@ static Mesh *applyModifier(ModifierData *md,
 	if (subdiv_settings.level == 0) {
 		return result;
 	}
-	/* TODO(sergey): Try to re-use subdiv when possible. */
-	Subdiv *subdiv = BKE_subdiv_new_from_mesh(&subdiv_settings, mesh);
+	BKE_subdiv_settings_validate_for_mesh(&subdiv_settings, mesh);
+	Subdiv *subdiv = subdiv_descriptor_ensure(smd, &subdiv_settings, mesh);
 	if (subdiv == NULL) {
-		/* Happens on bad topology, ut also on empty input mesh. */
+		/* Happens on bad topology, but also on empty input mesh. */
 		return result;
 	}
 	/* TODO(sergey): Decide whether we ever want to use CCG for subsurf,
-	 * maybe when it is a last modifier in the stack?
-	 */
+	 * maybe when it is a last modifier in the stack? */
 	if (true) {
 		result = subdiv_as_mesh(smd, ctx, mesh, subdiv);
 	}
 	else {
 		result = subdiv_as_ccg(smd, ctx, mesh, subdiv);
 	}
-	/* TODO(sergey): Cache subdiv somehow. */
 	// BKE_subdiv_stats_print(&subdiv->stats);
-	BKE_subdiv_free(subdiv);
+	if (subdiv != smd->subdiv) {
+		BKE_subdiv_free(subdiv);
+	}
 	return result;
 }