Graphics

Printing taller patterns

The next example shows how several lines of graphics can be formed into a figure taller than eight dots. It uses programming techniques for producing textured or repetitive patterns.

In the following program, the lines inside each pair of FOR and NEXT statements have been indented so that you can see how the program works; the spaces are not needed for the program to run.

100 WIDTH "LPT1:"

110LPRINTCHR$;2;;&;CHR$(8); 120FORR=lTO6

130LPRINT CHR$(27);"K";CHR$(lOO);CHR$(O);

140FORX=lTO 50

150LPRINTCHR$(170);CHR$(85);

160NEXT X : LPRINT

170NEXT R

180LPRINT CHR$(27);"@"

If you run the program you will see how it combines six print lines into a pattern.

There are five basic steps that the program goes through to produce this kind of pattern:

1.The computer is prevented from adding any extra characters by the WIDTH statement (line 100).

2.The line spacing is changed to 8/72 of an inch. This is the height of the dot patterns used in the program (line 110).

3.The program goes through the graphics command the required number of times (line 120 and 170).

Software and Graphics 4-15