By Theo Gray. When the program has loaded you will be
given a title screen where you can
choose one of the following things:
"E" - This will clear the screen and
then draw a set of example
spirals.
"O" - This option allows you to design
your own screens with as many
spirals as you like on one screen
at once.
First you are asked to choose a
colour (1-7), although I don't
think there is anything wrong
with using colours above 7 to
create different effects.
Then you will be asked for an X
and a Y co-ordinate. This will
give the point for the spiral to
start drawing from.
Then you are asked for the number
of half turns you want. 2 will
take the spiral round once
completely.
Next you are asked for the width
of the gap between each
spiralling line. If this is a
negative number then the spiral
will be drawn 180 degrees round
from normal.
Finally you asked to choose the
procedure to use - normal or
other. The 'normal' procedure
draws spirals with the start and
finish points in a horizontal
line, and the 'other' procedure
draws them with the start and
finish points in a vertical line.
"A" - ends the program
The procedures which draw the spirals
are very short and simple, and are
called:
PROCdraw(t%,x%,y%,c%,w%)
and
PROCdrawsin(t%,x%,y%,c%,w%)
which can be used in any application
and are almost exactly the same.
Editor: Try entering these in response
to the prompts:
6,320,512,6,100,O
5,320,512,6,-100,O
6,960,512,6,-100,O
5,960,512,6,100,O
3,640,768,6,100,O
5,640,768,5,-100,O
6,640,256,5,-100,O
3,640,256,5,100,O
6,640,512,12,20,N
5,640,512,11,-20,N
This data is similar to that in the
demo program, it will give you
something to experiment with. Try
altering the values slightly each time
to see what happens.