I’m used to the ye-olde Copybits, which has a source and a desitnation rectangle, like this:
CopyBits (srcBits,dstBits: BitMap;
srcRect,dstRect:Rect; mode:Integer;
maskRgn:RgnHandle);
This allows you to have a bitmap in memory, and copy a subset (srcRect), such as the top half of the bitmap, to the screen. Also, by changing the size of the destination rectangle (dstRect), it is possible to stretch the image.
I’ve found that by playing with the imageStim.size, I can stretch the image, but is their anyway to copy/blit/display only a part of the image (e.g. the the top half)?