diff options
Diffstat (limited to 'source/blender/blenlib/intern/math_matrix.c')
| -rw-r--r-- | source/blender/blenlib/intern/math_matrix.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/source/blender/blenlib/intern/math_matrix.c b/source/blender/blenlib/intern/math_matrix.c index e09fae7d140..0fd947b6b1a 100644 --- a/source/blender/blenlib/intern/math_matrix.c +++ b/source/blender/blenlib/intern/math_matrix.c @@ -931,6 +931,13 @@ float determinant_m3_array(const float m[3][3]) m[2][0] * (m[0][1] * m[1][2] - m[0][2] * m[1][1])); } +float determinant_m4_mat3_array(const float m[4][4]) +{ + return (m[0][0] * (m[1][1] * m[2][2] - m[1][2] * m[2][1]) - + m[1][0] * (m[0][1] * m[2][2] - m[0][2] * m[2][1]) + + m[2][0] * (m[0][1] * m[1][2] - m[0][2] * m[1][1])); +} + bool invert_m3_ex(float m[3][3], const float epsilon) { float tmp[3][3]; @@ -1641,6 +1648,19 @@ void mat4_to_size(float size[3], const float mat[4][4]) size[2] = len_v3(mat[2]); } +/* This computes the overall volume scale factor of a transformation matrix. + * For an orthogonal matrix, it is the product of all three scale values. + * Returns a negative value if the transform is flipped by negative scale. */ +float mat3_to_volume_scale(const float mat[3][3]) +{ + return determinant_m3_array(mat); +} + +float mat4_to_volume_scale(const float mat[4][4]) +{ + return determinant_m4_mat3_array(mat); +} + /* this gets the average scale of a matrix, only use when your scaling * data that has no idea of scale axis, examples are bone-envelope-radius * and curve radius */ |