CGA horizontal line with pattern assembler procedure

[Tronix]

Hello,

i want make new demo (or rather intro) for CGA and XT (8088 4,7Mhz). CGA mode - standart mode 320x200x4 color (mode 4 or 5). For "twister bar" effect, like this:

i need fast assembler procedure drawing horizontal line with pattern, becouse twister had 4 faces and CGA have 3 color (+1 black). So i need draw lines like this:

red pixel|white pixel|red pixel|white pixel|red pixel
white pixel|white pixel|cyan|white pixel|white pixel|cyan

Also looking for CGA artist, but dithering isn't true. For example, this images looking great:

And also i am looking AdLib musicant and second coder (assembler). Thanks.

 

[reenigne]

I have been dabbling a little in demo coding for 8088/CGA - I can probably write the horizontal line routine that you're looking for (if I don't already have it lying around somewhere) and maybe even be your second coder. I know a very good CGA artist as well. I have a few questions first though:

What is the high-level language you want to call it from? This makes a difference in how the routine is written - e.g. Pascal and C have different calling conventions for this architecture.

Do you have a particular party in mind for releasing this at? I ask because I am working on another demo for release at a particular party and don't want to be competing with myself! PM me with the answer if you don't want to mention it publicly.

For the demo effects I have been writing, I have found it useful to write all the code that will be running during the animation (i.e. everything except initial setup) in assembler rather than writing just drawing primitives in assembler. The reason is that the 8088 at 4.77MHz is so slow that the overhead of the function calls can make a quite significant difference to frame rate (not to mention that compiled code is nowhere near as fast as hand-written assembly for this platform).

What do you mean by "but dithering isn't true"? Are you saying that you like it, dislike it or that it doesn't matter?

 

[Trixter]

i need fast assembler procedure drawing horizontal line with pattern

Aren't you the same Tronix that created this: http://www.pouet.net/prod.php?which=61483
If so, I'm confused why you're asking these questions, because your previous production shows that you already know the basics of how CGA video memory is laid out, which also explains how to draw a horizontal line, with a pattern fill as well (use different bytes for even/odd lines).

 

[smeezekitty]

Off topic but it appears the last picture is supposed to use the RED/GREEN/YELLOW palette

 

[dr.zeissler]

was the demo/intro for cga released yet?