improved method of getting the tangent axis from a bmesh triangle,

rather then getting the longest edge, get the edge which which is most different from the 2 others ends up giving more useful results: for an isosceles triangle it returns the base weather its longer or shorter then the other sides.

1 files changed, 22 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/math_vector.c b/source/blender/blenlib/intern/math_vector.c
index 58d444f5794..572bc4526af 100644
--- a/source/blender/blenlib/intern/math_vector.c
+++ b/source/blender/blenlib/intern/math_vector.c
@@ -527,6 +527,28 @@ void dist_ensure_v2_v2fl(float v1[2], const float v2[2], const float dist)
 	}
 }
 
+void axis_sort_v3(const float axis_values[3], int r_axis_order[3])
+{
+	float v[3];
+	copy_v3_v3(v, axis_values);
+
+#define SWAP_AXIS(a, b) { \
+	SWAP(float, v[a],            v[b]); \
+	SWAP(int,   r_axis_order[a], r_axis_order[b]); \
+} (void)0
+
+	if (v[0] < v[1]) {
+		if (v[2] < v[0]) {  SWAP_AXIS(0, 2); }
+	}
+	else {
+		if (v[1] < v[2]) { SWAP_AXIS(0, 1); }
+		else             { SWAP_AXIS(0, 2); }
+	}
+	if (v[2] < v[1])     { SWAP_AXIS(1, 2); }
+
+#undef SWAP_AXIS
+}
+
 /***************************** Array Functions *******************************/
 
 double dot_vn_vn(const float *array_src_a, const float *array_src_b, const int size)