# OpenGL approach:
        # cx, cy are the X and Y centers of the image.
        # dx, dy are the X and Y translation factors.
        # angle is the rotation about the Z axis.
        GL.glPushMatrix()
        GL.glLoadIdentity()

        # So we rotate about the center.
        GL.glTranslated(cx, cy, 0)

        GL.glRotated(-angle, 0, 0, 1)
        GL.glTranslated(dx - cx, dy - cy, 0)
# With an X translate of 10 and angle of 45 degrees, printing out glGetDoublev(GL_MODELVIEW_MATRIX) gives:
# [[   0.70710677   -0.70710677    0.            0.        ]
#  [   0.70710677    0.70710677    0.            0.        ]
#  [   0.            0.            1.            0.        ]
#  [ -98.96759033  248.92893982    0.            1.        ]]


# Numpy approach:
            cosTheta = numpy.cos(angle)
            sinTheta = numpy.sin(angle)
            transform = numpy.array(
                    [[cosTheta, sinTheta, 0, dx],
                     [-sinTheta, cosTheta, 0, dy],
                     [0, 0, 1, dz],
                     [0, 0, 0, 1]])
# With those same transformation parameters, printing out transform gives:
# [[  0.70710678   0.70710678   0.          10.        ]
#  [ -0.70710678   0.70710678   0.           0.        ]
#  [  0.           0.           1.           0.        ]
#  [  0.           0.           0.           1.        ]]