Generation of random mazes via backtracking. This program is a port of the example written in XC=BASIC 3.1 by JJ Flash, with the addition of a "mouse" that moves inside the maze in search of the "cheese".
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DEFINE DEFAULT TYPE SIGNED WORD
VAR finalScrPosition AS WORD
CONST wall = 95 : CONST space = 32 : CONST mouse = 81
VAR nextDirection AS BYTE: VAR firstnextDirection AS BYTE
DIM dirArray(4) = #{ 2, -80, -2, 80 }
PRINT "press a key (i need randomness)"
WAIT KEY
CLS BLACK
INK WHITE
RANDOMIZE TIMER
restart:
FOR i = 0 TO 999: POKE Txa+i, wall: NEXT
FOR i = 0 TO 39: POKE Txa+i, space: NEXT
FOR i = 0 TO 39: POKE Txa+984+i,space: NEXT
screenPosition = Txa+79
FOR i = 1 TO 23
POKE screenPosition, space
screenPosition = screenPosition + 40
NEXT
steps = 0 : maxSteps = 0
screenPosition = Txa + 81 + (80 * RND(9)) + 2 * RND(9)
POKE screenPosition, 4 : ' "D"
digAnotherLocation:
nextDirection = RND(3) : firstnextDirection = nextDirection
IF steps > maxSteps THEN : maxSteps = steps: finalScrPosition = newScreenPosition : ENDIF
tryDiggingAgain:
newScreenPosition = screenPosition + dirArray(nextDirection)
IF PEEK(newScreenPosition) = wall THEN
POKE newScreenPosition, nextDirection
POKE screenPosition + ( dirArray(nextDirection)\2 ), space
screenPosition = newScreenPosition
steps = steps + 1
GOTO digAnotherLocation
ENDIF
nextDirection = (nextDirection + 1) AND 3
IF nextDirection <> firstnextDirection THEN : GOTO tryDiggingAgain : ENDIF
nextDirection = PEEK(screenPosition) : POKE screenPosition, space
steps = steps - 1
IF nextDirection < 4 THEN
screenPosition = screenPosition - dirArray(nextDirection)
GOTO digAnotherLocation
ENDIF
POKE screenPosition, 1 : POKE finalScrPosition, 2
HOME : PRINT "max steps: " ; maxSteps ; " - final loc: " ; finalScrPosition
POKE screenPosition, mouse : nextDirection = 2
mouseLabel:
WAIT VBL
newScreenPosition = screenPosition + (dirArray(nextDirection)\2)
IF newScreenPosition = finalScrPosition THEN : GOTO restart : ENDIF
IF PEEK(newScreenPosition) = space THEN
POKE newScreenPosition, mouse : POKE screenPosition, space
screenPosition = newScreenPosition
nextDirection = (nextDirection - 2) AND 3
ENDIF
nextDirection = (nextDirection - 1) AND 3
GOTO mouseLabel
The instructions here refer to compiling the example from the command line. For Microsoft Windows
users we suggest using UGBASIC-IDE, which allows
you to download and compile each single example with just one click.
Are instructions for your specific home computer / console missing? First of all, check if your computer
is supported by clicking here. If so, since ugBASIC is a language which does not provide abstractions, it is possible
that this example will not work on your target. If you think this is an issue, please click here.
In order to compile the example, type this command on the command line:
Linux
ugbc.c128 -O prg -o contrib_mazegen.prg contrib_mazegen.bas
Windows
ugbc.c128.exe -O prg -o contrib_mazegen.prg contrib_mazegen.bas
For Microsoft Windows users we suggest using UGBASIC-IDE, which allows
you to download and compile this example with just one click.
If you have found a problem trying to run this example, if you think there is a bug or, more
simply, you would like it to be improved, open an issue for this example on GitHub.
Thank you!
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