[Bf-blender-cvs] [0a446d7276] master: Add 3d to 2d plane mapping functions to math lib

[Luca Rood]

Commit: 0a446d7276e74e3c8472453948204ca6463d158e
Author: Luca Rood
Date:   Thu Dec 22 02:13:03 2016 -0200
Branches: master
https://developer.blender.org/rB0a446d7276e74e3c8472453948204ca6463d158e

Add 3d to 2d plane mapping functions to math lib

This adds two functions to project 3d coordinates onto a 3d plane,
to get 2d coordinates, essentially eliminating the plane's normal axis
from the coordinates.

Reviewed By: mont29

Differential Revision: https://developer.blender.org/D2460

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

M	source/blender/blenlib/BLI_math_geom.h
M	source/blender/blenlib/intern/math_geom.c

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

diff --git a/source/blender/blenlib/BLI_math_geom.h b/source/blender/blenlib/BLI_math_geom.h
index d33c2cb327..e3635be671 100644
--- a/source/blender/blenlib/BLI_math_geom.h
+++ b/source/blender/blenlib/BLI_math_geom.h
@@ -389,6 +389,8 @@ void box_minmax_bounds_m4(float min[3], float max[3],
 
 void map_to_tube(float *r_u, float *r_v, const float x, const float y, const float z);
 void map_to_sphere(float *r_u, float *r_v, const float x, const float y, const float z);
+void map_to_plane_v2_v3v3(float r_co[2], const float co[3], const float no[3]);
+void map_to_plane_axis_angle_v2_v3v3fl(float r_co[2], const float co[3], const float axis[3], const float angle);
 
 /********************************** Normals **********************************/
 
diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c
index 74ede1e755..8f5d84dfa0 100644
--- a/source/blender/blenlib/intern/math_geom.c
+++ b/source/blender/blenlib/intern/math_geom.c
@@ -4048,6 +4048,26 @@ void map_to_sphere(float *r_u, float *r_v, const float x, const float y, const f
 	}
 }
 
+void map_to_plane_v2_v3v3(float r_co[2], const float co[3], const float no[3])
+{
+	float target[3] = {0.0f, 0.0f, 1.0f};
+	float axis[3];
+
+	cross_v3_v3v3(axis, no, target);
+	normalize_v3(axis);
+
+	map_to_plane_axis_angle_v2_v3v3fl(r_co, co, axis, angle_normalized_v3v3(no, target));
+}
+
+void map_to_plane_axis_angle_v2_v3v3fl(float r_co[2], const float co[3], const float axis[3], const float angle)
+{
+	float tmp[3];
+
+	rotate_normalized_v3_v3v3fl(tmp, co, axis, angle);
+
+	copy_v2_v2(r_co, tmp);
+}
+
 /********************************* Normals **********************************/
 
 void accumulate_vertex_normals_tri(