Apple II "Planet" 227B Demo

Presented at Lovebyte Turbo 2022 (inside Evoke) Demoparty

By -=DEsIRE=-: code by deater

Should run on any Apple II+/IIe/IIc

Video

Sourcecode and Disk Image

You can get the submission here: planet256.zip (9k), 6 August 2022

The sourcecode is Applesoft BASIC. It fits in a tweet (280 bytes) but tokenized on disk it's 227 bytes.

0HGR2:FORR=0TO49:HPLOTRND(1)*280,RND(1)*99:NEXT
1X=X+1-(X*X/2600):Y=99-SQR(R*R-X*X):A=99+X/2-RND(1)*X:HCOLOR=3:HPLOT99-X,YTOA,Y:HCOLOR=1:HPLOTA,YTO99+X,Y
3IFX<49.9THEN1
4FORI=1TO7:X=0:T=I*I*I/4:Y=97+T
5HCOLOR=5*C:C=NOTC:Q=5+RND(1)*T:IFX+Q>279THENNEXT
6HPLOTX,YTOX+Q,Y:X=X+Q:GOTO5

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Various Notes

This was put together quickly for Lovebyte Turbo which was a special super-short demoparty held in 10 minutes at the larger Evoke party. The entire thing was shorter than some of the demos at Evoke (such as the amazing Area 5150 demo).

The entry is more or less an Apple II twitter bot entry.

Often I'll try to fix up those entries for use in places like Lovebyte. This one I'm not sure if it would be any faster/smaller if I converted it to assembly language.

The idea came from some examples going around on the BBC Micro bot, they found some sort of book that had a planet-maker. In the end I re-wrote it from scratch as the BBC architecture and bot lets them do all kinds of wacky things that wouldn't apply for the Apple II.

The one thing I did use was the square-root based circle drawing code, something I hadn't seem before and is actually pretty fast. Much faster than using sin/cos and possibly a lot smaller than using Bresenham.

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