Peter Shawbury

My favourite item in the previous issue of RISCOScode was the Yellow Pages "FunBox" program. It reminded me of the mental challenge I used to enjoy from trying to produce computer graphic doodles from a few lines of program code.
 
Danish programming genius, Jan Vibe, was the master of this art. Much of his material has been preserved in a recent drobe article. I love looking over Jan's code; clever, inspiring, and instructive.
 

 
Here is an idea that I've been playing around with which is in the style of Jan Vibe. 'Quirrel' produces 'dot art' from tiny BBC BASIC programs. The 23 lines of code that follow produce the above image.
 

100 REM >Quirrel-01
110 REM (c) Peter Shawbury
120 REM September 1st, 2009
130 REM version 1.00
140 :
150 MODE 21
160 :
170 RotInc = 20*SQR(2)
180 radius = 500
190 angle = 0
200 MOVE radius+640, 512
210 :
220 FOR point% = 1 TO 10000
230 RotInc += 7
240 angle += RotInc
250 angle = angle MOD 360
260 GCOL INT(angle/6)
270 radius = 3*RND(360)
280 x = radius*COS(RAD(angle)+RAD(radius/3))+640
290 y = radius*SIN(RAD(angle)+RAD(radius/3))+512
300 PLOT69, x, y
310 NEXT
320 END

 
If you need help typing in the listing, saving, loading or editing a BBC BASIC program, or running a program in a desktop window then see the yellow pages feature in the previous issue.
 
The real pleasure of such graphical doodles comes from changing a number here and there and seeing what is then different about the graphical output.

Explore !

*DOWNLOAD Quirrel

 
If typing in Peter's 23 line program is not your idea of a good time, download Quirrel-01, and a variation, Quirrel-02;