At 09:41 �� 19/2/2002 -0800, you wrote: >>>With large sprites you can reduce flicker significantly by combining the >>>background redraw >>>and sprite data in memory and write the lot to screen in one go. This >>>eliminates the problem >>>of writing to screen memory twice where the old and new sprite positions >>>overlap. >>> >>>Cheers >>>Malcolm
That's the idea anyway isn't it? Suppose we have one big sprite plus it's mask. 1. We grab the screen memory to be occupied during the next redraw. 2. We combine the sprite data and the copied memory using the mask 3. The result is written directly to the screen. 4. We then copyback the screen memory for the previous movement. and so on... The problem is that all these have to be provided as an extension to the OS else it's slow. (My quick example previously on the list could be at least 30% faster if the extensions were already there instead of combining a couple of TK facilities and compile the lot (I am sure Turbo cannot have code templates for everything in Turbo!) Phoebus
