Langton's ant: Difference between revisions

=={{header|Action!}}==

<lang Action!>DEFINE DIRN="0"

DEFINE DIRE="1"

DEFINE DIRS="2"

DEFINE DIRW="3"

DEFINE BLACK="1"

DEFINE WHITE="2"

DEFINE MAXX="159"

DEFINE MAXY="95"

BYTE FUNC TurnLeft(BYTE dir)

IF dir=DIRN THEN

RETURN (DIRW)

FI

RETURN (dir-1)

BYTE FUNC TurnRight(BYTE dir)

IF dir=DIRW THEN

RETURN (DIRN)

FI

RETURN (dir+1)

PROC DrawAnt(INT x,y)

BYTE c,dir

dir=DIRN

DO

c=Locate(x,y)

IF c=BLACK THEN

Color=WHITE

Plot(x,y)

dir=TurnLeft(dir)

ELSE

Color=BLACK

Plot(x,y)

dir=TurnRight(dir)

FI

IF dir=DIRN THEN

y==-1

IF y<0 THEN EXIT FI

ELSEIF dir=DIRE THEN

x==+1

IF X>MAXX THEN EXIT FI

ELSEIF dir=DIRS THEN

y==+1

IF Y>MAXY THEN EXIT FI

ELSE

x==-1

IF x<0 THEN EXIT FI

FI

OD

RETURN

PROC Main()

BYTE CH=$02FC

BYTE y

Graphics(7+16)

SetColor(0,0,2)

SetColor(1,0,12)

Color=2

FOR y=0 TO MAXY

DO

Plot(0,y) DrawTo(MAXX,y)

OD

DrawAnt(80,48)

DO UNTIL CH#$FF OD

CH=$FF

RETURN</lang>

{{out}}

[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Langton's_ant.png Screenshot from Atari 8-bit computer]