Math Lib: add axis_dominant_v3_ortho_single

2 files changed, 13 insertions, 1 deletions

diff --git a/source/blender/blenlib/BLI_math_geom.h b/source/blender/blenlib/BLI_math_geom.h
index d804b57ffe1..bf483386752 100644
--- a/source/blender/blenlib/BLI_math_geom.h
+++ b/source/blender/blenlib/BLI_math_geom.h
@@ -417,7 +417,8 @@ void  axis_dominant_v3_to_m3(float r_mat[3][3], const float normal[3]);
 
 MINLINE void  axis_dominant_v3(int *r_axis_a, int *r_axis_b, const float axis[3]);
 MINLINE float axis_dominant_v3_max(int *r_axis_a, int *r_axis_b, const float axis[3]) ATTR_WARN_UNUSED_RESULT;
-MINLINE int axis_dominant_v3_single(const float vec[3]);
+MINLINE int   axis_dominant_v3_single(const float vec[3]);
+MINLINE int   axis_dominant_v3_ortho_single(const float vec[3]);
 
 MINLINE int max_axis_v3(const float vec[3]);
 MINLINE int min_axis_v3(const float vec[3]);
diff --git a/source/blender/blenlib/intern/math_geom_inline.c b/source/blender/blenlib/intern/math_geom_inline.c
index 44b17681540..68a2e68db4f 100644
--- a/source/blender/blenlib/intern/math_geom_inline.c
+++ b/source/blender/blenlib/intern/math_geom_inline.c
@@ -199,6 +199,17 @@ MINLINE int axis_dominant_v3_single(const float vec[3])
 	       ((y > z) ? 1 : 2));
 }
 
+/* the dominant axis of an orthogonal vector */
+MINLINE int axis_dominant_v3_ortho_single(const float vec[3])
+{
+	const float x = fabsf(vec[0]);
+	const float y = fabsf(vec[1]);
+	const float z = fabsf(vec[2]);
+	return ((x < y) ?
+	       ((x < z) ? 0 : 2) :
+	       ((y < z) ? 1 : 2));
+}
+
 MINLINE int max_axis_v3(const float vec[3])
 {
 	const float x = vec[0];