1 files changed, 69 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c
index b79ae9f0042..21f82353ac2 100644
--- a/source/blender/blenlib/intern/math_geom.c
+++ b/source/blender/blenlib/intern/math_geom.c
@@ -2295,6 +2295,39 @@ void accumulate_vertex_normals(float n1[3], float n2[3], float n3[3],
 	}
 }
 
+/* Add weighted face normal component into normals of the face vertices.
+   Caller must pass pre-allocated vdiffs of nverts length. */
+#define VERT_BUF_SIZE 100
+void accumulate_vertex_normals_poly(float **vertnos, float polyno[3],
+	float **vertcos, float vdiffs[][3], int nverts)
+{
+	int i;
+
+	/* calculate normalized edge directions for each edge in the poly */
+	for (i = 0; i < nverts; i++) {
+		sub_v3_v3v3(vdiffs[i], vertcos[(i+1) % nverts], vertcos[i]);
+		normalize_v3(vdiffs[i]);
+	}
+
+	/* accumulate angle weighted face normal */
+	{
+		const float *prev_edge = vdiffs[nverts-1];
+		int i;
+
+		for(i=0; i<nverts; i++) {
+			const float *cur_edge = vdiffs[i];
+			
+			/* calculate angle between the two poly edges incident on
+			   this vertex */
+			const float fac= saacos(-dot_v3v3(cur_edge, prev_edge));
+
+			/* accumulate */
+			madd_v3_v3fl(vertnos[i], polyno, fac);
+			prev_edge = cur_edge;
+		}
+	}
+}
+
 /********************************* Tangents **********************************/
 
 /* For normal map tangents we need to detect uv boundaries, and only average
@@ -2951,3 +2984,39 @@ float form_factor_hemi_poly(float p[3], float n[3], float v1[3], float v2[3], fl
 
 	return contrib;
 }
+
+/* evaluate if entire quad is a proper convex quad */
+ int is_quad_convex_v3(const float *v1, const float *v2, const float *v3, const float *v4)
+ {
+	float nor[3], nor1[3], nor2[3], vec[4][2];
+	
+	/* define projection, do both trias apart, quad is undefined! */
+	normal_tri_v3( nor1,v1, v2, v3);
+	normal_tri_v3( nor2,v1, v3, v4);
+	nor[0]= ABS(nor1[0]) + ABS(nor2[0]);
+	nor[1]= ABS(nor1[1]) + ABS(nor2[1]);
+	nor[2]= ABS(nor1[2]) + ABS(nor2[2]);
+
+	if(nor[2] >= nor[0] && nor[2] >= nor[1]) {
+		vec[0][0]= v1[0]; vec[0][1]= v1[1];
+		vec[1][0]= v2[0]; vec[1][1]= v2[1];
+		vec[2][0]= v3[0]; vec[2][1]= v3[1];
+		vec[3][0]= v4[0]; vec[3][1]= v4[1];
+	}
+	else if(nor[1] >= nor[0] && nor[1]>= nor[2]) {
+		vec[0][0]= v1[0]; vec[0][1]= v1[2];
+		vec[1][0]= v2[0]; vec[1][1]= v2[2];
+		vec[2][0]= v3[0]; vec[2][1]= v3[2];
+		vec[3][0]= v4[0]; vec[3][1]= v4[2];
+	}
+	else {
+		vec[0][0]= v1[1]; vec[0][1]= v1[2];
+		vec[1][0]= v2[1]; vec[1][1]= v2[2];
+		vec[2][0]= v3[1]; vec[2][1]= v3[2];
+		vec[3][0]= v4[1]; vec[3][1]= v4[2];
+	}
+	
+	/* linetests, the 2 diagonals have to instersect to be convex */
+	if( isect_line_line_v2(vec[0], vec[2], vec[1], vec[3]) > 0 ) return 1;
+	return 0;
+}