Atari XL User Manual

Graphics
139
the XL draws a line from the posi tion of the last
PLOT or DRAWTO to the point specified by the
coordinates after the DRA WTO command.
You now know enough to produce line drawings of
all kinds. Try a few experiments.
This program produces a lacy pattern by drawing
lines close together on the mode 7 display, which
has twice as many rows and columns as the mode 5
display but is otherwise the same.
10 REM LACE
20 GRAPHICS 7
30 COLOR 1
40 FOR X=O TO 159 STEP 2
50 PLOT 79, 0
60 DRAWTO X, 79
70 NEXT X
Filling in the Colours
As well as drawing points and lines on the screen,
you can fill in areas of colour. The command used
is XIO, but to fill in an area you must first define
the outline of the shape. The sequence is as follows:
1
PLOT the bottom right-hand corner of the
shape to be filled.
2
DRAWTO the top right-hand corner.
3 DRAWTO the top left-hand corner.
4 Use POSITION to define the bottom left-hand
corner of the shape.
5 POKE the number of the colour you are using
into location 765.

Atari XL Specifications

General

Brand	Atari
Model	XL
Category	Desktop
Language	English