Light Source Position

A light source's position is affected by the current transformation.

Lights should be defined after the camera transformation, in order to define them in "world" coordinates.

They can also be moved with transformations, just like an object.

# Make local light come from position (5, 0, 7)
    glPushMatrix()
    glTranslatef(5, 0, 7)
    glLightfv(GL_LIGHT0, GL_POSITION, [0, 0, 0, 1])
    glPopMatrix()