Fix T44530 UV islands fail on subsurf after mirror modifier.

Caused by own commit that changed island detection code. In the case of
modifiers we don't want to take winding information into account, but
left the code since there are use cases (like painting) which could use
this.

3 files changed, 7 insertions, 4 deletions

diff --git a/source/blender/blenkernel/BKE_mesh_mapping.h b/source/blender/blenkernel/BKE_mesh_mapping.h
index da44c989146..dcf5d2ed78d 100644
--- a/source/blender/blenkernel/BKE_mesh_mapping.h
+++ b/source/blender/blenkernel/BKE_mesh_mapping.h
@@ -102,7 +102,7 @@ typedef struct MeshElemMap {
 /* mapping */
 UvVertMap *BKE_mesh_uv_vert_map_create(
         struct MPoly *mpoly, struct MLoop *mloop, struct MLoopUV *mloopuv,
-        unsigned int totpoly, unsigned int totvert, int selected, float *limit);
+        unsigned int totpoly, unsigned int totvert, int selected, float *limit, bool use_winding);
 UvMapVert *BKE_mesh_uv_vert_map_get_vert(UvVertMap *vmap, unsigned int v);
 void       BKE_mesh_uv_vert_map_free(UvVertMap *vmap);
 
diff --git a/source/blender/blenkernel/intern/mesh_mapping.c b/source/blender/blenkernel/intern/mesh_mapping.c
index ebdbd3aac8a..cc5006efacb 100644
--- a/source/blender/blenkernel/intern/mesh_mapping.c
+++ b/source/blender/blenkernel/intern/mesh_mapping.c
@@ -55,7 +55,7 @@
  * but for now this replaces it because its unused. */
 
 UvVertMap *BKE_mesh_uv_vert_map_create(struct MPoly *mpoly, struct MLoop *mloop, struct MLoopUV *mloopuv,
-                                       unsigned int totpoly, unsigned int totvert, int selected, float *limit)
+                                       unsigned int totpoly, unsigned int totvert, int selected, float *limit, bool use_winding)
 {
 	UvVertMap *vmap;
 	UvMapVert *buf;
@@ -109,7 +109,10 @@ UvVertMap *BKE_mesh_uv_vert_map_create(struct MPoly *mpoly, struct MLoop *mloop,
 				buf++;
 			}
 
-			winding[a] = cross_poly_v2((const float (*)[2])tf_uv, (unsigned int)nverts) > 0;
+			if (use_winding)
+				winding[a] = cross_poly_v2((const float (*)[2])tf_uv, (unsigned int)nverts) > 0;
+			else
+				winding[a] = 0;
 		}
 	}
 
diff --git a/source/blender/blenkernel/intern/subsurf_ccg.c b/source/blender/blenkernel/intern/subsurf_ccg.c
index a4e0eaaa324..f81d5825120 100644
--- a/source/blender/blenkernel/intern/subsurf_ccg.c
+++ b/source/blender/blenkernel/intern/subsurf_ccg.c
@@ -300,7 +300,7 @@ static int ss_sync_from_uv(CCGSubSurf *ss, CCGSubSurf *origss, DerivedMesh *dm,
 	float uv[3] = {0.0f, 0.0f, 0.0f}; /* only first 2 values are written into */
 
 	limit[0] = limit[1] = STD_UV_CONNECT_LIMIT;
-	vmap = BKE_mesh_uv_vert_map_create(mpoly, mloop, mloopuv, totface, totvert, 0, limit);
+	vmap = BKE_mesh_uv_vert_map_create(mpoly, mloop, mloopuv, totface, totvert, 0, limit, false);
 	if (!vmap)
 		return 0;