copy from pytouhou/utils/matrix.py
copy to pytouhou/utils/matrix.pyx
--- a/pytouhou/utils/matrix.py
+++ b/pytouhou/utils/matrix.pyx
@@ -12,35 +12,28 @@
 ## GNU General Public License for more details.
 ##
 
-#TODO: find/learn to use a proper lib
+from libc.math cimport sin, cos
+
 
-from math import sin, cos
-
-class Matrix(object):
-    def __init__(self, data=None):
+cdef class Matrix:
+    def __init__(Matrix self, data=None):
         self.data = data or [[0] * 4 for i in xrange(4)]
 
 
-    def mult(self, other_matrix):
-        d1 = self.data
-        d2 = other_matrix.data
-        return Matrix([[sum(d1[i][a] * d2[a][j] for a in xrange(4)) for j in xrange(4)] for i in xrange(4)])
-
-
-    def flip(self):
+    cpdef flip(Matrix self):
         data = self.data
         a, b, c, d = data[0]
         data[0] = [-a, -b, -c, -d]
 
 
-    def scale(self, x, y, z):
+    cpdef scale(Matrix self, x, y, z):
         d1 = self.data
         d1[0] = [a * x for a in d1[0]]
         d1[1] = [a * y for a in d1[1]]
         d1[2] = [a * z for a in d1[2]]
 
 
-    def scale2d(self, x, y):
+    cpdef scale2d(Matrix self, x, y):
         data = self.data
         d1a, d1b, d1c, d1d = data[0]
         d2a, d2b, d2c, d2d = data[1]
@@ -48,7 +41,7 @@ class Matrix(object):
         data[1] = [d2a * y, d2b * y, d2c * y, d2d * y]
 
 
-    def translate(self, x, y, z):
+    cpdef translate(Matrix self, x, y, z):
         data = self.data
         a, b, c = data[3][:3]
         a, b, c = a * x, b * y, c * z
@@ -60,7 +53,7 @@ class Matrix(object):
         data[2] = [d3a + c, d3b + c, d3c + c, d3d + c]
 
 
-    def rotate_x(self, angle):
+    cpdef rotate_x(Matrix self, angle):
         d1 = self.data
         cos_a = cos(angle)
         sin_a = sin(angle)
@@ -68,7 +61,7 @@ class Matrix(object):
                         [sin_a * d1[1][i] + cos_a * d1[2][i] for i in range(4)])
 
 
-    def rotate_y(self, angle):
+    cpdef rotate_y(Matrix self, angle):
         d1 = self.data
         cos_a = cos(angle)
         sin_a = sin(angle)
@@ -76,50 +69,10 @@ class Matrix(object):
                         [- sin_a * d1[0][i] + cos_a * d1[2][i] for i in range(4)])
 
 
-    def rotate_z(self, angle):
+    cpdef rotate_z(Matrix self, angle):
         d1 = self.data
         cos_a = cos(angle)
         sin_a = sin(angle)
         d1[0], d1[1] = ([cos_a * d1[0][i] - sin_a * d1[1][i] for i in range(4)],
                         [sin_a * d1[0][i] + cos_a * d1[1][i] for i in range(4)])
 
-
-    @classmethod
-    def get_translation_matrix(cls, x, y, z):
-        return cls([[1., 0., 0., x],
-                    [0., 1., 0., y],
-                    [0., 0., 1., z],
-                    [0., 0., 0., 1.]])
-
-
-    @classmethod
-    def get_scaling_matrix(cls, x, y, z):
-        return cls([[x,  0., 0., 0.],
-                    [0., y,  0., 0.],
-                    [0., 0., z,  0.],
-                    [0., 0., 0., 1.]])
-
-
-    @classmethod
-    def get_rotation_matrix(cls, angle, axis):
-        """Only handles axis = x, y or z."""
-        cos_a = cos(angle)
-        sin_a = sin(angle)
-        if axis == 'x':
-            return Matrix([[    1.,     0.,     0.,     0.],
-                           [    0.,  cos_a, -sin_a,     0.],
-                           [    0.,  sin_a,  cos_a,     0.],
-                           [    0.,     0.,     0.,     1.]])
-        elif axis == 'y':
-            return Matrix([[ cos_a,     0.,  sin_a,     0.],
-                           [    0.,     1.,     0.,     0.],
-                           [-sin_a,     0.,  cos_a,     0.],
-                           [    0.,     0.,     0.,     1.]])
-        elif axis == 'z':
-            return Matrix([[ cos_a, -sin_a,     0.,     0.],
-                           [ sin_a,  cos_a,     0.,     0.],
-                           [    0.,     0.,     1.,     0.],
-                           [    0.,     0.,     0.,     1.]])
-        else:
-            raise Exception
-