--- a/pytouhou/utils/matrix.pyx
+++ b/pytouhou/utils/matrix.pyx
@@ -17,14 +17,14 @@ from ctypes import c_float
 
 
 cdef class Matrix:
-    def __init__(Matrix self, data=None):
+    def __init__(self, data=None):
         self.data = data or [[1, 0, 0, 0],
                              [0, 1, 0, 0],
                              [0, 0, 1, 0],
                              [0, 0, 0, 1]]
 
 
-    def __mul__(Matrix self, Matrix other):
+    def __mul__(self, Matrix other):
         out = Matrix()
         d1 = self.data
         d2 = other.data
@@ -35,25 +35,25 @@ cdef class Matrix:
         return out
 
 
-    def get_c_data(Matrix self):
+    def get_c_data(self):
         data = sum(self.data, [])
         return (c_float * 16)(*data)
 
 
-    cpdef flip(Matrix self):
+    cpdef flip(self):
         data = self.data
         a, b, c, d = data[0]
         data[0] = [-a, -b, -c, -d]
 
 
-    cpdef scale(Matrix self, x, y, z):
+    cpdef scale(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]]
 
 
-    cpdef scale2d(Matrix self, x, y):
+    cpdef scale2d(self, x, y):
         data = self.data
         d1a, d1b, d1c, d1d = data[0]
         d2a, d2b, d2c, d2d = data[1]
@@ -61,7 +61,7 @@ cdef class Matrix:
         data[1] = [d2a * y, d2b * y, d2c * y, d2d * y]
 
 
-    cpdef translate(Matrix self, x, y, z):
+    cpdef translate(self, x, y, z):
         data = self.data
         a, b, c = data[3][:3]
         a, b, c = a * x, b * y, c * z
@@ -73,7 +73,7 @@ cdef class Matrix:
         data[2] = [d3a + c, d3b + c, d3c + c, d3d + c]
 
 
-    cpdef rotate_x(Matrix self, angle):
+    cpdef rotate_x(self, angle):
         d1 = self.data
         cos_a = cos(angle)
         sin_a = sin(angle)
@@ -81,7 +81,7 @@ cdef class Matrix:
                         [sin_a * d1[1][i] + cos_a * d1[2][i] for i in range(4)])
 
 
-    cpdef rotate_y(Matrix self, angle):
+    cpdef rotate_y(self, angle):
         d1 = self.data
         cos_a = cos(angle)
         sin_a = sin(angle)
@@ -89,7 +89,7 @@ cdef class Matrix:
                         [- sin_a * d1[0][i] + cos_a * d1[2][i] for i in range(4)])
 
 
-    cpdef rotate_z(Matrix self, angle):
+    cpdef rotate_z(self, angle):
         d1 = self.data
         cos_a = cos(angle)
         sin_a = sin(angle)