Fix simple subsurf on wire edges

Subsurf on wire edges gave smooth results even if set to simple
subdiv. Added a field to the CCG meshIFC to flag simple subdivision,
then when syncing vertices simply skip moving vertices if in
simple-subdiv mode.

This change affects two places, the level-1 build in sync and the
subdivision up to other levels.

Fixes bug [#32268] Simple Subsurf Modifier gives unexpected results on
edges without faces
projects.blender.org/tracker/index.php?func=detail&aid=32268&group_id=9&atid=498

1 files changed, 12 insertions, 7 deletions

diff --git a/source/blender/blenkernel/intern/subsurf_ccg.c b/source/blender/blenkernel/intern/subsurf_ccg.c
index 5c387e8cee0..b2762d23ef3 100644
--- a/source/blender/blenkernel/intern/subsurf_ccg.c
+++ b/source/blender/blenkernel/intern/subsurf_ccg.c
@@ -113,7 +113,8 @@ typedef enum {
 	CCG_USE_ARENA = 2,
 	CCG_CALC_NORMALS = 4,
 	/* add an extra four bytes for a mask layer */
-	CCG_ALLOC_MASK = 8
+	CCG_ALLOC_MASK = 8,
+	CCG_SIMPLE_SUBDIV = 16
 } CCGFlags;
 
 static CCGSubSurf *_getSubSurf(CCGSubSurf *prevSS, int subdivLevels,
@@ -133,7 +134,10 @@ static CCGSubSurf *_getSubSurf(CCGSubSurf *prevSS, int subdivLevels,
 
 		ccgSubSurf_getUseAgeCounts(prevSS, &oldUseAging, NULL, NULL, NULL);
 
-		if (oldUseAging != useAging) {
+		if ((oldUseAging != useAging) ||
+			(ccgSubSurf_getSimpleSubdiv(prevSS) !=
+			 !!(flags & CCG_SIMPLE_SUBDIV)))
+		{
 			ccgSubSurf_free(prevSS);
 		}
 		else {
@@ -156,6 +160,7 @@ static CCGSubSurf *_getSubSurf(CCGSubSurf *prevSS, int subdivLevels,
 		ifc.vertDataSize += sizeof(float) * 3;
 	if (flags & CCG_ALLOC_MASK)
 		ifc.vertDataSize += sizeof(float);
+	ifc.simpleSubdiv = !!(flags & CCG_SIMPLE_SUBDIV);
 
 	if (useArena) {
 		CCGAllocatorIFC allocatorIFC;
@@ -3474,7 +3479,7 @@ struct DerivedMesh *subsurf_make_derived_from_derived(
         float (*vertCos)[3],
         SubsurfFlags flags)
 {
-	int useSimple = smd->subdivType == ME_SIMPLE_SUBSURF;
+	int useSimple = (smd->subdivType == ME_SIMPLE_SUBSURF) ? CCG_SIMPLE_SUBDIV : 0;
 	CCGFlags useAging = smd->flags & eSubsurfModifierFlag_DebugIncr ? CCG_USE_AGING : 0;
 	int useSubsurfUv = smd->flags & eSubsurfModifierFlag_SubsurfUv;
 	int drawInteriorEdges = !(smd->flags & eSubsurfModifierFlag_ControlEdges);
@@ -3483,7 +3488,7 @@ struct DerivedMesh *subsurf_make_derived_from_derived(
 	if (flags & SUBSURF_FOR_EDIT_MODE) {
 		int levels = (smd->modifier.scene) ? get_render_subsurf_level(&smd->modifier.scene->r, smd->levels) : smd->levels;
 
-		smd->emCache = _getSubSurf(smd->emCache, levels, 3, useAging | CCG_CALC_NORMALS);
+		smd->emCache = _getSubSurf(smd->emCache, levels, 3, useSimple | useAging | CCG_CALC_NORMALS);
 		ss_sync_from_derivedmesh(smd->emCache, dm, vertCos, useSimple);
 
 		result = getCCGDerivedMesh(smd->emCache,
@@ -3498,7 +3503,7 @@ struct DerivedMesh *subsurf_make_derived_from_derived(
 		if (levels == 0)
 			return dm;
 		
-		ss = _getSubSurf(NULL, levels, 3, CCG_USE_ARENA | CCG_CALC_NORMALS);
+		ss = _getSubSurf(NULL, levels, 3, useSimple | CCG_USE_ARENA | CCG_CALC_NORMALS);
 
 		ss_sync_from_derivedmesh(ss, dm, vertCos, useSimple);
 
@@ -3529,7 +3534,7 @@ struct DerivedMesh *subsurf_make_derived_from_derived(
 		}
 
 		if (useIncremental && (flags & SUBSURF_IS_FINAL_CALC)) {
-			smd->mCache = ss = _getSubSurf(smd->mCache, levels, 3, useAging | CCG_CALC_NORMALS);
+			smd->mCache = ss = _getSubSurf(smd->mCache, levels, 3, useSimple | useAging | CCG_CALC_NORMALS);
 
 			ss_sync_from_derivedmesh(ss, dm, vertCos, useSimple);
 
@@ -3538,7 +3543,7 @@ struct DerivedMesh *subsurf_make_derived_from_derived(
 			                           useSubsurfUv, dm);
 		}
 		else {
-			CCGFlags ccg_flags = CCG_USE_ARENA | CCG_CALC_NORMALS;
+			CCGFlags ccg_flags = useSimple | CCG_USE_ARENA | CCG_CALC_NORMALS;
 			
 			if (smd->mCache && (flags & SUBSURF_IS_FINAL_CALC)) {
 				ccgSubSurf_free(smd->mCache);