def useTracker(self):
"""
camera.useTracker() -> void
Offsets the camera (should be called after use()) based
on the current position of the tracker.
"""
if self.trackPosOffset:
# Calculate the offset relative to the camera - rather than relative to the world.
x = mult3D(self.yz, self.trackPosOffset[X_AXIS])
y = mult3D(self.up, self.trackPosOffset[Y_AXIS])
z = mult3D(self.vpn, self.trackPosOffset[Z_AXIS])
offset = add3D(x, y)
offset = add3D(offset, z)
GL.glTranslatef(*offset)
if self.trackRotMatrix:
GL.glMultMatrix(*self.trackRotMatrix)
