TML Pascal Tricks
Volume Number: 6
Issue Number: 3
Column Tag: Pascal Procedures
By Paul Diegenbach, Amsterdam, the Netherlands
XCMD - drawing in a Hypercard stack
The attractiveness of Hypercard is for a large part due to it graphical
possibilities. Nice cards always mean nice graphics. The Hypertalk language allows
drawing on the screen under program control. When we tear the tools menu off the
menubar, we can actually see the actions as the tools flop from pen to brush to marquee
and so on. Nice to watch, but oh so slow. Ever tried to draw a complicated graph in
Hypercard? I tried it in an attempt to simulate the differentiation of an egg to all the
different cells an embryo consists of. One of the theories implies the evaluation of
some differential equations and then drawing a thousand points on the screen.
The idea was to let students be able to change the parameters in the equations and