transform.py

from math import *
import numpy as np
from matrix import matrix


class transform(matrix):

    def __init__(self):
        super().__init__(np.identity(4))

    def identity(self):
        return self

    def translate(self, Tx=0.0, Ty=0.0, Tz=0.0):
        self.set(0, 3, Tx)
        self.set(1, 3, Ty)
        self.set(2, 3, Tz)
        return self

    def scale(self, Sx=1.0, Sy=1.0, Sz=1.0):
        self.set(0, 0, Sx)
        self.set(1, 1, Sy)
        self.set(2, 2, Sz)
        return self

    def rotate(self, A=matrix(np.ones((3, 1))), angle=0.0):
        A = A.normalize()
        V = matrix(np.zeros((4, 4)))
        V.set(0, 1, -A.get(2, 0))
        V.set(0, 2, A.get(1, 0))
        V.set(1, 0, A.get(2, 0))
        V.set(1, 2, -A.get(0, 0))
        V.set(2, 0, -A.get(1, 0))
        V.set(2, 1, A.get(0, 0))
        return self + V.scalarMultiply(sin(angle)) + (V * V).scalarMultiply(1.0 - cos(angle))