posted 05-26-2009 06:08 PM         

The API's use only work on Windows NT 4.0, 2000, XP and Vista. It is not supported on 95/98/ME.

I am having some fun playing with this.

I do have to say the API's are a little confusing IMO and not consistant (BitBlts have to be dealt with differently than regular drawing).

posted 05-26-2009 06:11 PM         

One could draw all the frames for rotation when creating the sprite and simply flip frames, but that uses a lot more memory.

Also rotation done on the fly (I would have to rotate the curent sprite image and then draw the new image into the sprite buffer) will be a lot slower than dynamically creating all the frames ahead of time.

Sprites can flip though, which means that to get 360 degrees of rotation (in 1 degree intervals) would only require 90 images.

posted 05-27-2009 04:03 PM         

GDI+ calls the same API's (from the GDI) that I am using, so it is possible this feature is actually just part of the GDI (from XP on) and GDI+ just takes advantage of it.

If you would like to download a DDT app I wrote which rotates a bitmap (sorry, no source code) so you can see it be done (using the GDI alone), download using this link: