Math Library: add functions cross_poly_v2, cross_tri_v2

also added utility macro for removing elements in the middle of an array

1 files changed, 17 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/math_geom_inline.c b/source/blender/blenlib/intern/math_geom_inline.c
index ac5c0033067..1910b964d78 100644
--- a/source/blender/blenlib/intern/math_geom_inline.c
+++ b/source/blender/blenlib/intern/math_geom_inline.c
@@ -34,6 +34,23 @@
 
 #include <string.h>
 
+/********************************** Polygons *********************************/
+
+MINLINE float cross_tri_v2(const float v1[2], const float v2[2], const float v3[2])
+{
+	return (v1[0] - v2[0]) * (v2[1] - v3[1]) + (v1[1] - v2[1]) * (v3[0] - v2[0]);
+}
+
+MINLINE float area_tri_signed_v2(const float v1[2], const float v2[2], const float v3[2])
+{
+	return 0.5f * ((v1[0] - v2[0]) * (v2[1] - v3[1]) + (v1[1] - v2[1]) * (v3[0] - v2[0]));
+}
+
+MINLINE float area_tri_v2(const float v1[2], const float v2[2], const float v3[2])
+{
+	return fabsf(area_tri_signed_v2(v1, v2, v3));
+}
+
 /****************************** Spherical Harmonics **************************/
 
 MINLINE void zero_sh(float r[9])