Sinclair QL

~erBASIC has a set of turtle graphics commands
Jnmand
.:,,,uP
. ':NDOWN
')VE
;ClN
;ClNlD
Function
stop drawing
start drawing
move
the turtle
turn the turtle
turn to a speCific heading
turtle
graphics
c set of commands is the minimum and normally would be used within another
:edure
to expand on the commands. For example
100 DEFine PROCedure forward(distance)
110 MOVE distance
120 END DEFine
130 DEFine PROCedure backwards(distance)
140 MOVE-distance
150 END DEFine
160 DEFine PROCedure LefttangLe)
170 TURN ang Le
180 END DEFine
190 DEFine PROCedure right(angLe)
200 TURN -ang Le
210
END DEFine
"'5e will define some of the more famous turtle graphic commands.
ally the turtle's pen is up and the turtle IS pointing at 00, which is to the rlght·hand
• '0 of the window
~ FILL command will also work with figures drawn with turtle graphics. Also ordinary
c.;JhICS and turtle graphics can be mixed, although the direction of the turtle is not
'::llf,ed by the ordinary graphics commands.
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