[entivore]

Reading from video memory is a big no-no, but to make certain things look really really good you have to combine colors. For example, giving a character a black aura (or any color aura). I wish to have these auras, and maybe a few explosions or other such effects but I dunno how to do it without a major engine overhaul. I've tried having a screen size buffer, drawing to it, and then blitting it all at once but it slows things down quite a bit, especially after I upgraded my tile drawing to blit from video memory to video memory.

I had some ideas, but none seem practical enough.

#1 - Limit the background in situations where translucency would arise (for example, an all blue or all black background, then just have a graphic for each background)

#2 - Instead of half colors, simply make the aura out of a swiss cheese pattern with lots of no-draw pixels, like this:

* * *
* *
* * *

#3 - Just read from video memory and hope it doesn't slow down too much

Well anyway, anyone have any more suggestions or comments?
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*Only in darkness can one truely shine*

[janus]

A few vram reads/writes is never too bad, you just don't want to be doing fullscreen vram manipulation. If your code is optimized enough it'll work fine.

[Tenshi]

- Read from Video Ram once, generate a table of values, read from then on from the table?
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- Jaeda

[DrunkenCoder]

A long long time ago, during a summer many many months ago, there was a Alphablending thread anyway the results was something like:
80FPS on PIII 600MHz while doing fullscreenblends in 800x600
then memorybandwidth became the performancehog so almost anything should be acceptable.
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If there's life after death there is no death, if there's no death we never live. | ENTP