Move function out of mathutils to: BLI_math_rotation --- single_axis_angle_to_mat3(mat3, axis, angle), copied out from mathutils, axis arg is a char 'X/Y/Z' rather then a vector like axis_angle_to_mat3().

1 files changed, 46 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/math_rotation.c b/source/blender/blenlib/intern/math_rotation.c
index 6800b59c2c7..ef286e1d102 100644
--- a/source/blender/blenlib/intern/math_rotation.c
+++ b/source/blender/blenlib/intern/math_rotation.c
@@ -771,6 +771,52 @@ void mat4_to_axis_angle(float axis[3], float *angle,float mat[4][4])
 	quat_to_axis_angle(axis, angle,q);
 }
 
+
+
+void single_axis_angle_to_mat3(float mat[3][3], const char axis, const float angle)
+{
+	const float angle_cos= cosf(angle);
+	const float angle_sin= sinf(angle);
+
+	switch(axis) {
+	case 'X': /* rotation around X */
+		mat[0][0] =  1.0f;
+		mat[0][1] =  0.0f;
+		mat[0][2] =  0.0f;
+		mat[1][0] =  0.0f;
+		mat[1][1] =  angle_cos;
+		mat[1][2] =  angle_sin;
+		mat[2][0] =  0.0f;
+		mat[2][1] = -angle_sin;
+		mat[2][2] =  angle_cos;
+		break;
+	case 'Y': /* rotation around Y */
+		mat[0][0] =  angle_cos;
+		mat[0][1] =  0.0f;
+		mat[0][2] = -angle_sin;
+		mat[1][0] =  0.0f;
+		mat[1][1] =  1.0f;
+		mat[1][2] =  0.0f;
+		mat[2][0] =  angle_sin;
+		mat[2][1] =  0.0f;
+		mat[2][2] =  angle_cos;
+		break;
+	case 'Z': /* rotation around Z */
+		mat[0][0] =  angle_cos;
+		mat[0][1] =  angle_sin;
+		mat[0][2] =  0.0f;
+		mat[1][0] = -angle_sin;
+		mat[1][1] =  angle_cos;
+		mat[1][2] =  0.0f;
+		mat[2][0] =  0.0f;
+		mat[2][1] =  0.0f;
+		mat[2][2] =  1.0f;
+		break;
+	default:
+		assert("invalid axis");
+	}
+}
+
 /****************************** Vector/Rotation ******************************/
 /* TODO: the following calls should probably be depreceated sometime         */