add matrix_is_invertible

src/tkc/matrix.c

@@ -145,3 +145,18 @@ matrix_t* matrix_transform_pointf(matrix_t* m, float x, float y, float* ox, floa
 
   return m;
 }
+
+static double matrix_compute_determinant(matrix_t* m) {
+  double a = m->a0;
+  double b = m->a1;
+  double c = m->a2;
+  double d = m->a3;
+
+  return a * d - b * c;
+}
+
+bool_t matrix_is_invertible(matrix_t* m) {
+  double det = matrix_compute_determinant(m);
+
+  return TK_ISFINITE(det) && det != 0.;
+}

src/tkc/matrix.h

@@ -159,6 +159,16 @@ matrix_t* matrix_transform_point(matrix_t* m, xy_t x, xy_t y, xy_t* out_x, xy_t*
  */
 matrix_t* matrix_transform_pointf(matrix_t* m, float x, float y, float* ox, float* oy);
 
+/**
+ * @method matrix_is_invertible
+ * 判断matrix是否可逆。
+ *
+ * @param {matrix_t*} m 矩阵对象。
+ *
+ * @return {bool_t} 返回TRUE表示可逆，否则表示不可逆。
+ */
+bool_t matrix_is_invertible(matrix_t* m);
+
 END_C_DECLS
 
 #endif /*TK_MATRIX_H*/