BASIC FUNCTIONS
, SECTION 5. 17
POINT
5. 17. 3 Funct:ipn POINT return!) the 'colour' of the. specifi~d pixel.
Syntax A= POINT (X,Y)
Example 10 REM Invert the graphics screen
20 FOR X = 0 TO 239
30 FOR Y
= 0 TO 63
40 IF POINT(X,Y)
= 1 THEN PRESET (X,Y) ELSE PSET (X,Y)
50 NEXT Y:NEXT X
Remarks An odd number returned by the function indicates a black
pixel, while an even number indicates a white. pixel. If
the' co-ordinates are out of range then -1
is' "rehimed,
VER, V09F PAGE 5 - 103
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