Hi and welcome to PGD.

I've placed you code around code blocks for better readability.

As for your question. I'm not entirely sure how the disc is supposed to rotate. Your code suggests the rotation is just an animation and not a programmed effect.

At first sight the code looks okay. Have you entered the patternheight and -width in the dximagelist correctly?
It could be that you need to initialize the AnimPos property.

In any case there's a demo that came with delphix in the Samples\Sprite\Shoot directory that might give you a few hints.