"""Transformation matrix.""" class Matrix(list): def __init__(self, a=1, b=0, c=0, d=1, e=0, f=0, matrix=None): if matrix is None: matrix = [[a, b, 0], [c, d, 0], [e, f, 1]] super().__init__(matrix) def __matmul__(self, other): assert len(self[0]) == len(other) == len(other[0]) == 3 return Matrix(matrix=[ [sum(self[i][k] * other[k][j] for k in range(3)) for j in range(3)] for i in range(len(self))]) @property def invert(self): d = self.determinant return Matrix(matrix=[ [ (self[1][1] * self[2][2] - self[1][2] * self[2][1]) / d, (self[0][1] * self[2][2] - self[0][2] * self[2][1]) / -d, (self[0][1] * self[1][2] - self[0][2] * self[1][1]) / d, ], [ (self[1][0] * self[2][2] - self[1][2] * self[2][0]) / -d, (self[0][0] * self[2][2] - self[0][2] * self[2][0]) / d, (self[0][0] * self[1][2] - self[0][2] * self[1][0]) / -d, ], [ (self[1][0] * self[2][1] - self[1][1] * self[2][0]) / d, (self[0][0] * self[2][1] - self[0][1] * self[2][0]) / -d, (self[0][0] * self[1][1] - self[0][1] * self[1][0]) / d, ], ]) @property def determinant(self): assert len(self) == len(self[0]) == 3 return ( self[0][0] * (self[1][1] * self[2][2] - self[1][2] * self[2][1]) - self[1][0] * (self[0][1] * self[2][2] - self[0][2] * self[2][1]) + self[2][0] * (self[0][1] * self[1][2] - self[0][2] * self[1][1])) def transform_point(self, x, y): return (Matrix(matrix=[[x, y, 1]]) @ self)[0][:2] @property def values(self): (a, b), (c, d), (e, f) = [column[:2] for column in self] return a, b, c, d, e, f