Posted By
Gaia
on 2013-09-13
15:55:18
|  Re: Two Tech Demos
OK, so I have finally found the PAL color mixer I have ported from C64. It mixes new colours from existing ones using PAL TV standard side effects so it won't work under NTSC.
Here is the original article:
http://www.larshaugseth.com/c64/colmix.html
And here is my conversion
PRG: http://yape.homeserver.hu/download/colmix3.prg
AS65 Source: http://yape.homeserver.hu/download/colmix3.asm (use it with PLUS4IDE)
Here's how it looks. Up and the bottom are the original colours, in the middle rows you can see the 2 similar (but not identical!) new colours:
You'll notice that I have changed the colour pairs here and there... hopefully for the better!  The paired colours should not ideally be on the opposing ends of the YUV colour circle otherwise we end up with greyish new colours.
Don't forget to enable PAL emulation in your favourite emulator otherwise you'll see only horizontal stripes. You can play around with the luminance (LDA argument #$33 in the source ) if you wish and have even all combinations mixed but don't forget that the mixed colours should always have the same luminance!
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