Fix T99684: Upgrade Averages Island Scale with options Scale UV and Shear

Differential Revision: https://developer.blender.org/D15421

2 files changed, 17 insertions, 0 deletions

diff --git a/source/blender/blenlib/BLI_math_matrix.h b/source/blender/blenlib/BLI_math_matrix.h
index 2cd2a299d53..c2dafbe3a1a 100644
--- a/source/blender/blenlib/BLI_math_matrix.h
+++ b/source/blender/blenlib/BLI_math_matrix.h
@@ -238,6 +238,7 @@ bool invert_m3_ex(float m[3][3], float epsilon);
 bool invert_m3_m3_ex(float m1[3][3], const float m2[3][3], float epsilon);
 
 bool invert_m3(float R[3][3]);
+bool invert_m2_m2(float R[2][2], const float A[2][2]);
 bool invert_m3_m3(float R[3][3], const float A[3][3]);
 bool invert_m4(float R[4][4]);
 bool invert_m4_m4(float R[4][4], const float A[4][4]);
diff --git a/source/blender/blenlib/intern/math_matrix.c b/source/blender/blenlib/intern/math_matrix.c
index ce9abc36cad..fcd017b3082 100644
--- a/source/blender/blenlib/intern/math_matrix.c
+++ b/source/blender/blenlib/intern/math_matrix.c
@@ -1116,6 +1116,22 @@ double determinant_m3_array_db(const double m[3][3])
           m[2][0] * (m[0][1] * m[1][2] - m[0][2] * m[1][1]));
 }
 
+bool invert_m2_m2(float m1[2][2], const float m2[2][2])
+{
+  adjoint_m2_m2(m1, m2);
+  float det = determinant_m2(m2[0][0], m2[1][0], m2[0][1], m2[1][1]);
+
+  bool success = (det != 0.0f);
+  if (success) {
+    m1[0][0] /= det;
+    m1[1][0] /= det;
+    m1[0][1] /= det;
+    m1[1][1] /= det;
+  }
+
+  return success;
+}
+
 bool invert_m3_ex(float m[3][3], const float epsilon)
 {
   float tmp[3][3];