Mathematics for programming graphical rep of a carousel?

[pluviosilla]

I need to program a rotating slide photo carousel, and it is a bit tricky, because in addition to the rotation of the carousel that holds the "slide" images, you need to correctly rotate the individual slide images. The rotation of the individual slide image is obviously dependent on the rotation of the carousel, but how?

Does anyone know where I can find the equations that describe the relationship of the rotation of the slides to the rotation of the carousel?

Thanks.

 

[pluviosilla]

Picture of a classic slide carousel:
http://images.google.com/imgres?img...ow+projector&start=40&ndsp=20&um=1&hl=en&sa=N