Is it possible to switch which side of a polygon is treated as the back face during rendering or can it only be set once?
Yes it´s possible…Unforunately I forgot how it is called.Look for something like glPolygonWinding or glWinding.
glFrontFace(GL_CCW) or glFrontFace(GL_CW)
read the red book …
I have almost finished the red book niko and you are wrong, as far as I know they can only be called in an init routine.
You can call glFrontFace anytime as long there is a valid rendering context and it is not inbetween glBegin/glEnd.
Thanks for the clarification
There is also glCullFace(GL_FRONT) and glCullFace(GL_BACK), glFrontFace() determines what is front and back and glCullFace() determines which side should be culled.