# -*- encoding: utf-8 -*-
##
## Copyright (C) 2012 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published
## by the Free Software Foundation; version 3 only.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##

from libc.math cimport sqrt


cdef class Vector:
    def __init__(self, float x, float y, float z):
        self.x = x
        self.y = y
        self.z = z


    cdef Vector sub(self, Vector other):
        cdef float x, y, z

        x = self.x - other.x
        y = self.y - other.y
        z = self.z - other.z

        return Vector(x, y, z)


cdef Vector cross(Vector vec1, Vector vec2):
    return Vector(vec1.y * vec2.z - vec2.y * vec1.z,
                  vec1.z * vec2.x - vec2.z * vec1.x,
                  vec1.x * vec2.y - vec2.x * vec1.y)


cdef float dot(Vector vec1, Vector vec2):
    return vec1.x * vec2.x + vec2.y * vec1.y + vec1.z * vec2.z


cdef Vector normalize(Vector vec):
    cdef float normal

    normal = 1 / sqrt(vec.x * vec.x + vec.y * vec.y + vec.z * vec.z)
    return Vector(vec.x * normal, vec.y * normal, vec.z * normal)