[Coco] Scrolling 3D Checkerboard Field

[Dennis Bathory-Kitsz]

At 08:31 AM 7/24/2007 -0700, Andrew wrote:
>I have been trying off and on to find a description and/or source code 
>(in -any- language) on how to render (and animate) a scrolling 
>"checkerboard" field.

I implemented a scrolling effect by keeping two screen pages in memory,
switching the addressing to the VDG, updating the one not displayed, and
then displaying the updated one. It was visually glitchless that way, and
looked like actual motion.

I forget the details, but somewhere was published an article called
"Scroll-a-Roll" that gave the code for it. The documentation is here:
 <ftp://maltedmedia.com/coco/GreenMountainMicro/_MISC/SCRLDOX.PCL>
These dox don't include the source code. I thought I had all the
documentation and source codes in a notebook here, but that one seems to be
missing. The online dox should give you an idea of how to implement it,
though.

Dennis