BLI_math: add 'equals_m4m4' (and 'm3' variant) helpers.

source/blender/blenlib/BLI_math_matrix.h

@@ -246,6 +246,9 @@ bool is_negative_m4(float mat[4][4]);
 bool is_zero_m3(float mat[3][3]);
 bool is_zero_m4(float mat[4][4]);
 
+bool equals_m3m3(float mat1[3][3], float mat2[3][3]);
+bool equals_m4m4(float mat1[4][4], float mat2[4][4]);
+
 /* SpaceTransform helper */
 typedef struct SpaceTransform {
 	float local2target[4][4];

source/blender/blenlib/intern/math_matrix.c

@@ -1828,6 +1828,21 @@ bool is_zero_m4(float mat[4][4])
 	        is_zero_v4(mat[3]));
 }
 
+bool equals_m3m3(float mat1[3][3], float mat2[3][3])
+{
+	return (equals_v3v3(mat1[0], mat2[0]) &&
+	        equals_v3v3(mat1[1], mat2[1]) &&
+	        equals_v3v3(mat1[2], mat2[2]));
+}
+
+bool equals_m4m4(float mat1[4][4], float mat2[4][4])
+{
+	return (equals_v4v4(mat1[0], mat2[0]) &&
+	        equals_v4v4(mat1[1], mat2[1]) &&
+	        equals_v4v4(mat1[2], mat2[2]) &&
+	        equals_v4v4(mat1[3], mat2[3]));
+}
+
 /* make a 4x4 matrix out of 3 transform components */
 /* matrices are made in the order: scale * rot * loc */
 /* TODO: need to have a version that allows for rotation order... */