A transform engine within a graphics pipeline is configured to rotate, or rotate and translate, one or more polygons in response to a screen orientation. The transform engine obtains a texture from a pre-rotated polygon and applies the texture to the rotated polygon. An image that reflects the rotated...http://www.google.fr/patents/US7629987?utm_source=gb-gplus-shareBrevet US7629987 - Accelerated rotation for displaying an image
