[Bf-blender-cvs] [80ff0dd03c4] soc-2018-npr: Change cusp edge shift criteria

[Sebastian Parborg]

Commit: 80ff0dd03c4470f11a2e646bd288bc533f283fc7
Author: Sebastian Parborg
Date:   Wed Aug 8 17:23:43 2018 +0200
Branches: soc-2018-npr
https://developer.blender.org/rB80ff0dd03c4470f11a2e646bd288bc533f283fc7

Change cusp edge shift criteria

===================================================================

M	source/blender/modifiers/intern/MOD_mybmesh.c

===================================================================

diff --git a/source/blender/modifiers/intern/MOD_mybmesh.c b/source/blender/modifiers/intern/MOD_mybmesh.c
index 495fc337cab..e2e9ba1b905 100644
--- a/source/blender/modifiers/intern/MOD_mybmesh.c
+++ b/source/blender/modifiers/intern/MOD_mybmesh.c
@@ -133,9 +133,6 @@ typedef struct {
 	//Radial edge vert start idx
 	int radi_start_idx;
 
-	//are we in the cusp insertion step
-	bool is_cusp;
-
 	struct OpenSubdiv_Evaluator *eval;
 } MeshData;
 
@@ -1022,19 +1019,40 @@ static bool check_and_shift(BMVert *vert, const float new_loc[3], const float ne
 	}
 
 	//Will this shift a cusp edge
-	if( !m_d->is_cusp ){
-		int edge_i;
+	{
 		BMEdge *edge;
 		BMIter iter_e;
+		BMFace* f;
+		BMIter iter_f;
+		float mat[3][3];
+
+		copy_v3_v3(vert->co, new_loc);
 
 		BM_ITER_ELEM (edge, &iter_e, vert, BM_EDGES_OF_VERT) {
-			for(edge_i = 0; edge_i < m_d->cusp_edges->count; edge_i++){
-				BMEdge* cusp_edge = BLI_buffer_at(m_d->cusp_edges, Cusp, edge_i).cusp_e;
-				if( edge == cusp_edge ){
-					return false;
+			for(int cusp_i = 0; cusp_i < m_d->cusp_edges->count; cusp_i++){
+				Cusp cusp = BLI_buffer_at(m_d->cusp_edges, Cusp, cusp_i);
+				if( edge == cusp.cusp_e ){
+					bool still_inside_face = false;
+					//Check if moving this cusp edge will produce any folds
+					axis_dominant_v3_to_m3(mat, cusp.cusp_no);
+					BM_ITER_ELEM (f, &iter_f, edge, BM_FACES_OF_EDGE) {
+
+						// BM_face_point_inside_test is too inaccurate to use here as some overhangs are missed with it.
+						if( point_inside(mat, cusp.cusp_co, f) ){
+							still_inside_face = true;
+							break;
+						}
+					}
+					if (!still_inside_face){
+						copy_v3_v3(vert->co, old_loc);
+						return false;
+					}
 				}
 			}
 		}
+
+		//Move the vert back for future checks
+		copy_v3_v3(vert->co, old_loc);
 	}
 
 	//Check if the shift might/will cause a CCC face
@@ -1983,7 +2001,6 @@ static void cusp_detection( MeshData *m_d ){
 
 static void cusp_insertion(MeshData *m_d){
 	int cusp_i;
-	m_d->is_cusp = true;
 
 	for(cusp_i = 0; cusp_i < m_d->cusp_edges->count; cusp_i++){
 		BMVert *vert;
@@ -2019,7 +2036,6 @@ static void cusp_insertion(MeshData *m_d){
 
 		BLI_buffer_append(m_d->new_vert_buffer, Vert_buf, new_buf);
 	}
-	m_d->is_cusp = false;
 }
 
 static bool poke_and_move(BMFace *f, const float new_pos[3], const float du[3], const float dv[3], Radi_vert *r_vert, MeshData *m_d){
@@ -4456,7 +4472,6 @@ static Mesh *mybmesh_do(Mesh *mesh, MyBMeshModifierData *mmd, float cam_loc[3])
 		mesh_data.C_verts = &C_verts;
 		mesh_data.cusp_verts = &cusp_verts;
 		mesh_data.radi_vert_buffer = &radi_vert_buffer;
-		mesh_data.is_cusp = false;
 		mesh_data.eval = osd_eval;
 
         create_vert_mapping(&mesh_data);
@@ -4470,11 +4485,9 @@ static Mesh *mybmesh_do(Mesh *mesh, MyBMeshModifierData *mmd, float cam_loc[3])
 		// (6.2) Contour Insertion
 
 		if (mmd->flag & MOD_MYBMESH_CUSP_D) {
-			mesh_data.is_cusp = true;
 			TIMEIT_START(cusp_detect);
 			cusp_detection(&mesh_data);
 			TIMEIT_END(cusp_detect);
-			mesh_data.is_cusp = false;
 		}
 
 		if (mmd->flag & MOD_MYBMESH_FB_SPLIT) {