;Red [ ;World [ REBOL [ Title: "Mandelbrot fractal ASCII renderer, integer version for Rebol, Red and World" Author: "Marco Antoniazzi" file: %int-mandelbrot.r ; you must comment out all dates and tuples for Red date: 28-Dec-2013 version: 1.0.0 Purpose: "Show a Mandelbrot fractal on the console" License: { PD/CC0 http://creativecommons.org/publicdomain/zero/1.0/ } Notes: {Derived from John Niclasen, Kaj de Vos, Glenn Rhoads. Using only simple while loops. Change script header to test it with various rebol-ish languages. } Tabs: 4 library: [ level: 'beginner platform: 'all type: 'function domain: [math] tested-under: [ View 2.7.8.3.1 Saphir-View 2.101.0.3.1 Red 0.4.1 World [0 win32 2.1.1] ] support: none license: none see-also: none ] ] if 0 = first load form system/version [ ; for Red v.0.4.1 mod: func [a [integer!] b [integer!]] [a - (a / b * b)] ] ; using 1000 as a multiplier to use only integer numbers THRESHOLD: 16 * 1000 MAX_ITERATIONS: 1000 mandelbrot: func [ x [integer!] y [integer!] /local i cr ci zr zi zr2 zi2 zrzi ][ cr: y - 500 ;(to-integer 1000 / 2) ci: x zr: 0 zi: 0 i: 0 while [i < MAX_ITERATIONS] [ zrzi: zr * zi / 1000 zr2: zr * zr / 1000 zi2: zi * zi / 1000 zr: zr2 - zi2 + cr zi: zrzi + zrzi + ci if zr2 + zi2 > THRESHOLD [return i] i: i + 1 ] 0 ] ;start: now/time/precise ; only for Rebol and World b: " .,:;!/>)|&IH%*#" y: -1000 while [y < 1000] [ x: -1000 while [x < 1000] [ ; this is the most difficult part to write in a "multi-rebol-ish compatible" way ;prin either zero? mandelbrot y x [#"*"] [#" "] ;prin b/(1 + mod mandelbrot y x 16) ; with Red I must write prin b/(1 + mod (mandelbrot y x) 16) but then it does not work with World m: mandelbrot y x prin b/(1 + mod m 16) x: x + 26 ;to-integer 1000 / 38 ] prin "^/" y: y + 50 ;to-integer 1000 / 20 ] ;print ["Elapsed time:" now/time/precise - start] ; only for Rebol and World halt