Apple IIe - Page 167

Apple BASIC Reference Guide 167
between 0 and the number of shapes in the table. The optional
column and row denote the starting x and y coordinates for the
shape.
XDRAW uses the color which is the compliment of the color
which already exists at each point being plotted. The com-
plementary colors are as follows:
O(Black)
1(Green)
4(Black)
5(0range)
3(White)
2(Violet)
7(White)
6(Blue)
One other feature of XDRAW is that it allows a shape to be easily
erased.
If a shape is XDRAWn and then XDRAWn again with the
same parameters, the shape will be erased without erasing the
background .
Example
10 REM SET UP SCREEN
20 TEXT:HGR
30 FOR X = 7936 TO 7946
40 READ V:REM READ IN SHAPE
50 POKE X,V:REM POKE SHAPE INTO MEMORY
60 NEXT X
70 REM TELL WHERE SHAPE IS AT
80 POKE 232,0: POKE 233,31
90 REM PUT UP A BACKGROUND
100 HCOLOR = 3
110 HPLOT 20,20 TO 60,20 TO 20,70
120 PRINT "BACKGROUND SET UP"
130 INPUT "PRESS RETURN TO DISPLAY SHAPES";A$
140 ROT=O
150 SCALE = 10
160 XDRA W 1 AT 50,30
170 SCALE= 6
180
ROT= 4
190
XDRAW 1 AT 20,70
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