Guys! Guys! You gotta see this!

[Jess Ragan]

I figured out how to do color cycling, the way Japanese developers used to do it on the SG-1000 and MSX! Basically, you just have to re-define colors for a block of graphics during execution. There's no apparent limit to the number of times you can define the colors, so you can define new color sets as you please to make the colors seem to scroll upward through the graphics, or pulse ominously like the front of a sleeping Wii.

 

Anyway, check it out! I'm really happy about this. Special effects aren't common in ColecoVision games, but I think I could get a lot of use out of this.

testin.rom testin.bas

[Falonn]

This looks great, thanks for sharing!

 

Here is an animated GIF of the effect for passersby that might not have downloaded the ROM or checked out the code otherwise:

[artrag]

Cool

[Jess Ragan]

Looks that much nicer with scanlines. Like a neon sign!

 

I'm going to have to recheck the color codes; the bottoms of 1, 2, and 3 seem to have an unwanted white color cycling through them.

[Jess Ragan]

Yep, there were some stray white codes in there. This is more what I had in mind!

testin.bas testin.rom

[+cjherr]

Very slick!

[AnalogKid]

I'm surprised it's not used more in games because if used properly it's a clock-cycle cheap way of adding perceived animation to the game screen.  I've seen some really cool starfield backgrounds created this way.  
 

[Captain Cozmos]

I love the animation.
I wanted to see how small I could get this thing with pure assembly.

source included

 

Testin Minimal.rom

 

Main.asm

 

 

I updated the source with some commenting and a couple of corrections if you already DL it.

 

Edited June 18 by Captain Cozmos

[Jess Ragan]

Thanks much!

 

By the way, this dovetails nicely with CV BASIC expanding its compatibility to support the SV-318. I was wondering if I could color cycle with VPOKEs instead of DEFINE COLOR and DATA statements. The problem with the latter technique is that I have to use constants rather than variables, which means four static animations rather than having the colors flow smoothly from one row to the next. If you play any of Spectravideo's games, you'll notice that they've got an intro with colors flowing through the Spectravideo logo. I don't think I would have that kind of freedom with DEFINE COLOR.

[MrDave]

Looks great !