Spiro is a spirograph generator that I wrote for a programming competition between myself and a friend of mine at school. He used a 25MHz 486 and I used an A5000. I think you can guess the result of the competition.
Spiro requires you to specify five values. These are:
1) The size of the hole at the centre of the spirograph
2) The number of cycles of the line
3) How sharp the line curves
4) The number of times the colours repeat in each cycle
5) The type of pattern
This probably sounds like a load of jibberish, but to understand the values you need to understand the way I have generated the patterns. An easier way to find out what they do is to play around with them. Try 10, 101, 64, 3, and try pattern types one to four. After this try other values for all the settings. If you press return, the same value will be entered as you entered the time before.
In a conventional (paper) spirograph you cannot get such wide range of patterns as is avaiable in this program. Of the four pattern types, only one can be generated. A circle within another circle must move the same way as they are rotating. This is not so in this program, and allows interesting effects when a pattern loops in on itself.
NOTE: Spiro likes mode 27, but can be persuaded to run in mode 12. Changing the mode instruction from mode 27 to mode 12 tends to help this.
