Laser 128 - Page 127

BASIC COMMANDS AND STATEMENTS
The shape table in the computer's memory is
made up of separate bytes, which means that
only two complete vectors - of three bits
each - anq an incomplete vector - of only
two binary bits -can be stored in each byte
as there are only 8 bits within a single byte.
These incomplete vectors are movement
without plotting, and they are the only ones
possible in this part of the sha pe table byte.
As this is the case, unless you can arrange
your shape such that the non-pl otting vectors
are the very third vector in it, you should
set these two bits to zero (i.e. unused).
e.g. ] 10 DRAW l AT 140, 96
draws shape 1 at screen co-ordinates
(140, 96)
e.g. ] 10 SCALE = 2
] 20 ROT= 32
] 30 DRAW 2 AT 40, 40
] 40 FOR D = 1 TO 2000 : NEXT D
] 50 XDRAW 2 AT 40, 40
This program draws shape 2 in reverse
direction (i.e. rotated 180°) and in double
size at (40, 40). Then wait for a while and
clear the shape from the screen.
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