Revisiting the Dragon Curve

A few days ago I published code to draw the Heighway Dragon Curve. Here's a variation that's 3 lines shorter and plots the curve in 655360 cycles. The pMARS command line is pmarsv -s 90000 -c 1000000.

;redcode-fractal
;name Dragon Curve 2
;author John Metcalf

        width  equ 315
        stack  equ dragon+100
        plot   equ direct+width+1
        first  equ 80*width+50

        mov    #first,   plot
dragon  mov.ab count,    <plot
test    mov.b  @plot,    #0
        add.ba @plot,    direct
        div    #2,       @plot
        mod    #2,       test
        jmz    test,     test
        mod.a  #4,       direct
direct  add.b  3,        width+1
count   sub.ba #65536,   #1+1
        jmp    dragon,   -width+1

Dragon Curve in Redcode

The Heighway Dragon Curve is fractal line than goes through a series of 90° turns, creating a pattern which fills a 2 dimensional space. The program plots 32768 points in 458741 cycles. The pMARS command line is pmarsv -s 90000 -c 500000.

;redcode-fractal
;name Dragon Curve
;author John Metcalf

        width  equ 315
        stack  equ dragon+100

dragon  mov.x  paira,    <stack
recur   djn    dragon,   #15
        mod.a  #4,       direct
        add.b  *direct,  plot
plot    mov    >recur,   80*width+110
        mov.ba >stack,   ret
ret     jmp    0,        }stack
turn    add.a  @stack,   direct
        mov.x  pairb,    <stack
        jmp    recur

direct  dat    3,        width
paira   dat    turn-ret, -1
        dat    0,        -width
pairb   dat    plot-ret, 1

Corewar Programming Contest

The First International Corewar Programming Contest has just been announced, with a first prize of $50 sponsored by www.corewar.info.

The competition takes place in the unexplored area between '94nop and LP settings which has recently been investigated by Fizmo in Redcode Talk.

The exact settings are as follows:

Standard:	CWS'94
Coresize:	8000
Processes:	200
Entry length:	20
Points win:	3
Points tie:	1
Cycles:	80000
Rounds:	1000

The pMARS command line is pmars -p 200 -l 20 -r 1000. STP and LDP are forbidden, up to two entries are allowed and battles will take part in a round-robin tournament.

For more information, take a look at the announcement in rec.games.corewar.

Four Lines of Redcode

The Sierpinski triangle or gasket is a fractal named after the Polish mathematician Waclaw Sierpinski. Surprisingly the fractal can be generated with just 4 lines of Redcode:

        width  equ 126
        trail  equ (sum-CORESIZE%width)
        start  equ (trail-width+1)

sum     mov    #3,    @3
ptr     mov.b  trail, sum
        add.b  {ptr,  sum
        djn    sum,   #start

The magic incantation for pMARS is pmars -v 132. Alternatively set the width to 128 to view using CoreWin :-)