Munching squares

Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.

Befunge

Writes the image to stdout using the PPM format.

Burlesque

<lang burlesque> blsq ) 0 25r@{0 25r@\/{$$Sh2' P[}\/+]m[}m[sp

0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
1  0  3  2  5  4  7  6  9  8 11 10 13 12 15 14 17 16 19 18 21 20 23 22 25 24
2  3  0  1  6  7  4  5 10 11  8  9 14 15 12 13 18 19 16 17 22 23 20 21 26 27
3  2  1  0  7  6  5  4 11 10  9  8 15 14 13 12 19 18 17 16 23 22 21 20 27 26
4  5  6  7  0  1  2  3 12 13 14 15  8  9 10 11 20 21 22 23 16 17 18 19 28 29
5  4  7  6  1  0  3  2 13 12 15 14  9  8 11 10 21 20 23 22 17 16 19 18 29 28
6  7  4  5  2  3  0  1 14 15 12 13 10 11  8  9 22 23 20 21 18 19 16 17 30 31
7  6  5  4  3  2  1  0 15 14 13 12 11 10  9  8 23 22 21 20 19 18 17 16 31 30
8  9 10 11 12 13 14 15  0  1  2  3  4  5  6  7 24 25 26 27 28 29 30 31 16 17
9  8 11 10 13 12 15 14  1  0  3  2  5  4  7  6 25 24 27 26 29 28 31 30 17 16

10 11 8 9 14 15 12 13 2 3 0 1 6 7 4 5 26 27 24 25 30 31 28 29 18 19 11 10 9 8 15 14 13 12 3 2 1 0 7 6 5 4 27 26 25 24 31 30 29 28 19 18 12 13 14 15 8 9 10 11 4 5 6 7 0 1 2 3 28 29 30 31 24 25 26 27 20 21 13 12 15 14 9 8 11 10 5 4 7 6 1 0 3 2 29 28 31 30 25 24 27 26 21 20 14 15 12 13 10 11 8 9 6 7 4 5 2 3 0 1 30 31 28 29 26 27 24 25 22 23 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 31 30 29 28 27 26 25 24 23 22 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 0 1 2 3 4 5 6 7 8 9 17 16 19 18 21 20 23 22 25 24 27 26 29 28 31 30 1 0 3 2 5 4 7 6 9 8 18 19 16 17 22 23 20 21 26 27 24 25 30 31 28 29 2 3 0 1 6 7 4 5 10 11 19 18 17 16 23 22 21 20 27 26 25 24 31 30 29 28 3 2 1 0 7 6 5 4 11 10 20 21 22 23 16 17 18 19 28 29 30 31 24 25 26 27 4 5 6 7 0 1 2 3 12 13 21 20 23 22 17 16 19 18 29 28 31 30 25 24 27 26 5 4 7 6 1 0 3 2 13 12 22 23 20 21 18 19 16 17 30 31 28 29 26 27 24 25 6 7 4 5 2 3 0 1 14 15 23 22 21 20 19 18 17 16 31 30 29 28 27 26 25 24 7 6 5 4 3 2 1 0 15 14 24 25 26 27 28 29 30 31 16 17 18 19 20 21 22 23 8 9 10 11 12 13 14 15 0 1 25 24 27 26 29 28 31 30 17 16 19 18 21 20 23 22 9 8 11 10 13 12 15 14 1 0 </lang>

Must be converted to an image with a seperate program.

C

<lang c>#include <stdlib.h>

include <stdio.h>
include <math.h>
include <string.h>

void hue_to_rgb(double hue, double sat, unsigned char *p) { double x; int c = 255 * sat; hue /= 60; x = (1 - fabs(fmod(hue, 2) - 1)) * 255;

switch((int)hue) { case 0: p[0] = c; p[1] = x; p[2] = 0; return; case 1: p[0] = x; p[1] = c; p[2] = 0; return; case 2: p[0] = 0; p[1] = c; p[2] = x; return; case 3: p[0] = 0; p[1] = x; p[2] = c; return; case 4: p[0] = x; p[1] = 0; p[2] = c; return; case 5: p[0] = c; p[1] = 0; p[2] = x; return; } }

int main(void) { const int size = 512; int i, j; unsigned char *colors = malloc(size * 3); unsigned char *pix = malloc(size * size * 3), *p; FILE *fp;

for (i = 0; i < size; i++) hue_to_rgb(i * 240. / size, i * 1. / size, colors + 3 * i);

for (i = 0, p = pix; i < size; i++) for (j = 0; j < size; j++, p += 3) memcpy(p, colors + (i ^ j) * 3, 3);

fp = fopen("xor.ppm", "wb"); fprintf(fp, "P6\n%d %d\n255\n", size, size); fwrite(pix, size * size * 3, 1, fp); fclose(fp);

return 0; }</lang>

Output:

C++

include <windows.h>
include <string>

//-------------------------------------------------------------------------------------------------- using namespace std;

//-------------------------------------------------------------------------------------------------- const int BMP_SIZE = 512;

//-------------------------------------------------------------------------------------------------- class myBitmap { public:

   myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {}
   ~myBitmap()
   {

DeleteObject( pen ); DeleteObject( brush ); DeleteDC( hdc ); DeleteObject( bmp );

   }

   bool create( int w, int h )
   {

BITMAPINFO bi; ZeroMemory( &bi, sizeof( bi ) ); bi.bmiHeader.biSize = sizeof( bi.bmiHeader ); bi.bmiHeader.biBitCount = sizeof( DWORD ) * 8; bi.bmiHeader.biCompression = BI_RGB; bi.bmiHeader.biPlanes = 1; bi.bmiHeader.biWidth = w; bi.bmiHeader.biHeight = -h;

HDC dc = GetDC( GetConsoleWindow() ); bmp = CreateDIBSection( dc, &bi, DIB_RGB_COLORS, &pBits, NULL, 0 ); if( !bmp ) return false;

hdc = CreateCompatibleDC( dc ); SelectObject( hdc, bmp ); ReleaseDC( GetConsoleWindow(), dc );

width = w; height = h; return true;

   }

   void clear( BYTE clr = 0 )
   {

memset( pBits, clr, width * height * sizeof( DWORD ) );

   }

   void setBrushColor( DWORD bClr )
   {

if( brush ) DeleteObject( brush ); brush = CreateSolidBrush( bClr ); SelectObject( hdc, brush );

   }

   void setPenColor( DWORD c ) { clr = c; createPen(); }

   void setPenWidth( int w )   { wid = w; createPen(); }

   void saveBitmap( string path )
   {

BITMAPFILEHEADER fileheader; BITMAPINFO infoheader; BITMAP bitmap; DWORD wb;

GetObject( bmp, sizeof( bitmap ), &bitmap ); DWORD* dwpBits = new DWORD[bitmap.bmWidth * bitmap.bmHeight];

ZeroMemory( dwpBits, bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD ) ); ZeroMemory( &infoheader, sizeof( BITMAPINFO ) ); ZeroMemory( &fileheader, sizeof( BITMAPFILEHEADER ) );

infoheader.bmiHeader.biBitCount = sizeof( DWORD ) * 8; infoheader.bmiHeader.biCompression = BI_RGB; infoheader.bmiHeader.biPlanes = 1; infoheader.bmiHeader.biSize = sizeof( infoheader.bmiHeader ); infoheader.bmiHeader.biHeight = bitmap.bmHeight; infoheader.bmiHeader.biWidth = bitmap.bmWidth; infoheader.bmiHeader.biSizeImage = bitmap.bmWidth * bitmap.bmHeight * sizeof( DWORD );

fileheader.bfType = 0x4D42; fileheader.bfOffBits = sizeof( infoheader.bmiHeader ) + sizeof( BITMAPFILEHEADER ); fileheader.bfSize = fileheader.bfOffBits + infoheader.bmiHeader.biSizeImage;

GetDIBits( hdc, bmp, 0, height, ( LPVOID )dwpBits, &infoheader, DIB_RGB_COLORS );

HANDLE file = CreateFile( path.c_str(), GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL ); WriteFile( file, &fileheader, sizeof( BITMAPFILEHEADER ), &wb, NULL ); WriteFile( file, &infoheader.bmiHeader, sizeof( infoheader.bmiHeader ), &wb, NULL ); WriteFile( file, dwpBits, bitmap.bmWidth * bitmap.bmHeight * 4, &wb, NULL ); CloseHandle( file );

delete [] dwpBits;

   }

   HDC getDC() const     { return hdc; }
   int getWidth() const  { return width; }
   int getHeight() const { return height; }

private:

   void createPen()
   {

if( pen ) DeleteObject( pen ); pen = CreatePen( PS_SOLID, wid, clr ); SelectObject( hdc, pen );

   }

   HBITMAP bmp;
   HDC     hdc;
   HPEN    pen;
   HBRUSH  brush;
   void    *pBits;
   int     width, height, wid;
   DWORD   clr;

}; //-------------------------------------------------------------------------------------------------- class mSquares { public:

   mSquares()
   {
       bmp.create( BMP_SIZE, BMP_SIZE );
       createPallete();
   }

   void draw()
   {

HDC dc = bmp.getDC(); for( int y = 0; y < BMP_SIZE; y++ ) for( int x = 0; x < BMP_SIZE; x++ ) { int c = ( x ^ y ) % 256; SetPixel( dc, x, y, clrs[c] ); }

BitBlt( GetDC( GetConsoleWindow() ), 30, 30, BMP_SIZE, BMP_SIZE, dc, 0, 0, SRCCOPY ); //bmp.saveBitmap( "f:\\rc\\msquares_cpp.bmp" );

private:

   void createPallete()
   {

for( int x = 0; x < 256; x++ ) clrs[x] = RGB( x<<1, x, x<<2 );//rand() % 180 + 50, rand() % 200 + 50, rand() % 180 + 50 );

   unsigned int clrs[256];
   myBitmap bmp;

}; //-------------------------------------------------------------------------------------------------- int main( int argc, char* argv[] ) {

   ShowWindow( GetConsoleWindow(), SW_MAXIMIZE );
   srand( GetTickCount() );
   mSquares s; s.draw();
   return system( "pause" );

} //-------------------------------------------------------------------------------------------------- </lang>

C#

<lang csharp>using System.Drawing; using System.Drawing.Imaging; using System.Linq;

class XORPattern {

   static void Main()
   {
       var size = 0x100;
       var black = Color.Black.ToArgb();
       var palette = Enumerable.Range(black, size).Select(Color.FromArgb).ToArray();
       using (var image = new Bitmap(size, size))
       {
           for (var x = 0; x < size; x++)
           {
               for (var y = 0; y < size; y++)
               {
                   image.SetPixel(x, y, palette[x ^ y]);
               }
           }
           image.Save("XORPatternCSharp.png", ImageFormat.Png);
       }
   }

}</lang>

Output:

D

<lang d>void main() {

   import std.stdio;

   enum width = 512, height = 512;

   auto f = File("xor_pattern.ppm", "wb");
   f.writefln("P6\n%d %d\n255", width, height);
   foreach (immutable y; 0 .. height)
       foreach (immutable x; 0 .. width) {
           immutable c = (x ^ y) & ubyte.max;
           immutable ubyte[3] u3 = [255 - c, c / 2, c];
           f.rawWrite(u3);
       }

}</lang>

EchoLisp

Use the plot library, hsv->rgb ((x xor y) modulo m) as color table, and see the nice results here : http://www.echolalie.org/echolisp/help.html#bit-map . <lang scheme> (lib 'types) (lib 'plot) (plot-size 512 512) ;; for example

use m = 16, 32, 44, .. to change the definition (number of losanges)

(define (plot-munch (m 256)) (define PIX (pixels->int32-vector)) ;; get canvas image (define (pcolor x y) ;; color at (x,y) (hsv->rgb (// (bitwise-xor (modulo x m) (modulo y m)) m) 0.9 0.9)) (pixels-map pcolor PIX) (vector->pixels PIX)) ;; draw canvas image

(plot-much) ;; ESC to see tge drawing </lang>

Factor

<lang factor>USING: accessors images images.loader kernel math sequences ; IN: rosetta-code.munching-squares

img-data ( -- seq ) 256 sq [ B{ 0 0 0 255 } ] replicate ;

(munching) ( elt index -- elt' )

   256 /mod bitxor [ rest ] dip prefix ;

munching ( -- seq )

   img-data [ (munching) ] map-index B{ } concat-as ;

<munching-img> ( -- img )

   <image>
   { 256 256 }      >>dim
   BGRA             >>component-order
   ubyte-components >>component-type
   munching         >>bitmap ;

main ( -- ) <munching-img> "munching.png" save-graphic-image ;

MAIN: main</lang> Output image is identical to the Racket version.

Output:

FreeBASIC

<lang freebasic>' version 03-11-2016 ' compile with: fbc -s gui

Dim As ULong x, y, r, w = 256

ScreenRes w, w, 32

For x = 0 To w -1

   For y = 0 To w -1
       r =(x Xor y) And 255
       PSet(x, y), RGB(r, r , r)         ' gray scale
       ' PSet(x, y), RGB(r, 255 - r, 0)  ' red + green
       ' PSet(x, y), RGB(r, 0, 0)        ' red
   Next

GLSL

This is an example that will work directly on shadertoy.com, Example [1] <lang GLSL>vec3 color; float c,p; vec2 b;

void main(void) { vec2 uv = gl_FragCoord.xy / iResolution.xy; float scale = iResolution.x / iResolution.y; uv = uv-0.5; uv.y/=scale;

b = uv*256.0+256.0; c = 0.0;

for(float i=16.0;i>=1.0;i-=1.0) { p = pow(2.0,i);

if((p < b.x) ^^ (p < b.y)) { c += p; }

if(p < b.x) { b.x -= p; }

if(p < b.y) { b.y -= p; }

}

c=mod(c/128.0,1.0);

color = vec3(sin(c+uv.x*cos(uv.y*1.2)), tan(c+uv.y-0.3)*1.1, cos(c-uv.y+0.9));

gl_FragColor = vec4(color,1.0); }</lang>

Gnuplot

<lang gnuplot>set pm3d map set size square set isosamples 255,255 splot [0:255][0:255]-(floor(x)^floor(y))</lang>

Output:

Haskell

<lang haskell>import qualified Data.ByteString as BY (writeFile, pack)

import Data.Bits (xor)

main :: IO () main =

 BY.writeFile
   "out.pgm"
   (BY.pack
      (fmap (fromIntegral . fromEnum) "P5\n256 256\n256\n" ++
       [ x `xor` y
       | x <- [0 .. 255] 
       , y <- [0 .. 255] ]))</lang>

Go

<lang go>package main

import (

   "image"
   "image/png"
   "os"

)

func main() {

   g := image.NewGray(image.Rect(0, 0, 256, 256))
   for i := range g.Pix {
       g.Pix[i] = uint8(i>>8 ^ i)
   }
   f, _ := os.Create("xor.png")
   png.Encode(f, g)
   f.Close()

}</lang>

Icon and Unicon

<lang Icon>link printf

procedure main(A) #: XOR graphic

  wsize := 512
  cmax  := 32768
  wparms := ["Xmas Xor Graphic","g",sprintf("size=%d,%d",wsize),"bg=black"]
  &window := open!wparms | stop("Unable to open window")

  every y := 0 to wsize - 1 do
     every x := 0 to wsize - 1 do {
        c := cmax/wsize * iand(wsize-1,ixor(x,y))
        Fg(sprintf("%d,%d,%d",c,cmax-c,0))
        DrawPoint(x,y)
        }

 until Event() == &lpress     # wait for left button to quit
 close(&window)

end</lang>

Library: Icon Programming Library

printf.icn provides formatting

J

<lang J> require 'viewmat'

  viewmat ~:"1/&.#: ~ i.256</lang>

Java

Library: Swing

This example will repeat the pattern if you expand the window. <lang java>import java.awt.Color; import java.awt.Graphics;

import javax.swing.JFrame; import javax.swing.JPanel;

public class XorPattern extends JFrame{

   private JPanel xorPanel;

   public XorPattern(){
       xorPanel = new JPanel(){
           @Override
           public void paint(Graphics g) {
               for(int y = 0; y < getHeight();y++){
                   for(int x = 0; x < getWidth();x++){
                       g.setColor(new Color(0, (x ^ y) % 256, 0));
                       g.drawLine(x, y, x, y);
                   }
               }
           }
       };
       add(xorPanel);
       setSize(300, 300);
       setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       setVisible(true);
   }

   public static void main(String[] args){
       new XorPattern();
   }

}</lang>

jq

Works with: jq version 1.4

The following is an adaptation of the Ruby entry, but generates an SVG image file: <lang sh>jq -n -r -f Munching_squares.jq > Munching_squares.svg</lang> Part 1: Infrastructure <lang jq># Convert the input integer to an array of bits with lsb first def integer_to_lsb:

 [recurse(if . > 0 then ./2|floor else empty end) | . % 2] ;

input array of bits (with lsb first) is converted to an integer

def lsb_to_integer:

 reduce .[] as $bit
   # state: [power, ans]
   ([1,0]; (.[0] * 2) as $b | [$b, .[1] + (.[0] * $bit)])
 | .[1];

def xor(x;y):

  def lxor(a;b):  # a and/or b may be null
    if a == 1 then if b==1 then 0 else 1 end
    elif b==1 then if a==1 then 0 else 1 end
    else 0
    end;
  (x|integer_to_lsb) as $s
  | (y|integer_to_lsb) as $t
  | ([$s|length, $t|length] | max) as $length
  | reduce range(0;$length) as $i
     ([]; . + [ lxor($s[$i]; $t[$i]) ] )
  | lsb_to_integer;</lang>

Part 2: SVG <lang jq>def rgb2rgb:

 def p: (. + 0.5) | floor;  # to nearest integer
 "rgb(\(.red|p),\(.green|p),\(.blue|p))";

def svg(width; height):

 "<svg width='\(width // "100%")' height='\(height // "100%")'
          xmlns='http://www.w3.org/2000/svg'>";

def pixel(x; y; color):

 (color | if type == "string" then . else rgb2rgb end) as $c
 | "<circle r='1' cx='\(x)' cy='\(y)' fill='\($c)' />";</lang>

Part 3: xor pattern <lang jq># rgb is a JSON object: { "red": _, "green": _, "blue": _}

def xor_pattern(width; height; rgb1; rgb2):

   # create colour table
   256 as $size 
   | (reduce range(0;$size) as $i
       ([]; . + [ 
       {"red":   (rgb1.red + (rgb2.red - rgb1.red) * $i / $size), 
        "green": (rgb1.green + (rgb2.green - rgb1.green) * $i / $size), 
        "blue":  (rgb1.blue + (rgb2.blue - rgb1.blue) * $i / $size) }])
     )  as $colours
   # create the image
   | svg(width; height),
     ( (range(0;width) as $x
       | range(0;height) as $y
       |   pixel($x; $y; $colours[ xor($x; $y) % $size] ) ) ),
    "</svg>" ;</lang>

Part 4: Example <lang jq>def black: { "red": 0, "green": 0, "blue": 0}; def red: black + { "red": 255 }; def yellow: red + { "green": 255 };

xor_pattern(384; 384; red; yellow)</lang>

Julia

<lang julia>using Gtk, Colors, PerceptualColourMaps

function munchingsquares(ctx, w, h)

   extent = min(max(w, h), 256)
   colors = cmap("R1", N=extent)
   for i in 1:2:w-2, j in 1:2:h-2
       rectangle(ctx, i, j, i + 2, j + 2)
       c = colors[((UInt(i) ^ UInt(j)) % extent) + 1]
       set_source_rgb(ctx, red(c), blue(c), green(c))
       fill(ctx)
   end

end

const can = @GtkCanvas() const win = GtkWindow(can, "Munching Squares", 720, 360)

@guarded draw(can) do widget

   ctx = getgc(can)
   h = height(can)
   w = width(can)
   munchingsquares(ctx, w, h)

end

show(can) const cond = Condition() endit(w) = notify(cond) signal_connect(endit, win, :destroy) wait(cond) </lang>

Kotlin

<lang scala>// version 1.1.4-3

import javax.swing.JFrame import javax.swing.JPanel import java.awt.Graphics import java.awt.Graphics2D import java.awt.Color import java.awt.Dimension import java.awt.BorderLayout import java.awt.RenderingHints import javax.swing.SwingUtilities

class XorPattern : JPanel() {

   init {
       preferredSize = Dimension(256, 256)
       background = Color.white
   }

   override fun paint(gg: Graphics) {
       super.paintComponent(gg)
       val g = gg as Graphics2D
       g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
                          RenderingHints.VALUE_ANTIALIAS_ON)
       for (y in 0 until width) {
           for (x in 0 until height) {
               g.color = Color(0, (x xor y) % 256, 255)
               g.drawLine(x, y, x, y)
           }
       }
   }

}

fun main(args: Array<String>) {

   SwingUtilities.invokeLater {
       val f = JFrame()
       with (f) {
           defaultCloseOperation = JFrame.EXIT_ON_CLOSE
           title = "Munching squares"
           isResizable = false
           add(XorPattern(), BorderLayout.CENTER)
           pack()
           setLocationRelativeTo(null)
           isVisible = true
       }
   }

}</lang>

Liberty BASIC

   nomainwin

   w =512
   '   allow for title bar and window border
   WindowWidth  =w +2
   WindowHeight =w +34

   open "XOR Pattern" for graphics_nsb_nf as #w

   #w "trapclose quit"

   #w "down"

   for x =0 to w -1
       for y =0 to w -1
           b =( x xor y) and 255
           print b
           #w "color "; 255 -b; " "; b /2; " "; b
           #w "set "; x; " "; w -y -1
           scan
       next y
   next x

   #w "flush"

   wait

   sub quit j$
   close #w
   end
   end sub

</lang> Image available at [[2]]

Lua

Needs LÖVE 2D Engine <lang lua> local clr = {} function drawMSquares()

   local pts = {}
   for j = 0, hei - 1 do
       for i = 0, wid - 1 do
           idx = bit.bxor( i, j ) % 256
           pts[1] = { i, j, clr[idx][1], clr[idx][2], clr[idx][3], 255 }
           love.graphics.points( pts )
       end
   end

end function createPalette()

   for i = 0, 255 do
       clr[i] = { bit.band( i * 2.8, 255 ), bit.band( i * 3.2, 255 ), bit.band( i * 1.5, 255 ) }
   end

end function love.load()

   wid, hei = love.graphics.getWidth(), love.graphics.getHeight()
   canvas = love.graphics.newCanvas( wid, hei )
   love.graphics.setCanvas( canvas ); love.graphics.clear()
   love.graphics.setColor( 255, 255, 255 )
   createPalette(); drawMSquares(); 
   love.graphics.setCanvas()

end function love.draw()

   love.graphics.draw( canvas )

end </lang>

Mathematica

<lang Mathematica>ListDensityPlot[

Table[Table[
  FromDigits[BitXor[IntegerDigits[x, 2, 8], IntegerDigits[y, 2, 8]], 
   2], {x, 0, 255}], {y, 0, 255}]]</lang>

Output #1:

<lang Mathematica>ArrayPlot[Array[BitXor, {511, 511}]]</lang>

Output #2:

MATLAB

<lang matlab>size = 256; [x,y] = meshgrid([0:size-1]);

c = bitxor(x,y);

colormap bone(size); image(c); axis equal;</lang>

Output:

Microsoft Small Basic

<lang smallbasic>' Munching squares - smallbasic - 27/07/2018

 size=256
 GraphicsWindow.Width=size
 GraphicsWindow.Height=size
 For i=0 To size-1
   For j=0 To size-1
     BitXor() 'color=i Xor j
     GraphicsWindow.SetPixel(i,j,GraphicsWindow.GetColorFromRGB(0,color,color))
   EndFor
 EndFor

Sub BitXor '(i,j)->color

 n=i
 Int2Bit()
 ib=ret
 n=j
 Int2Bit()
 jb=ret
 color=0
 For k=1 to 8
   ki=Text.GetSubText(ib,k,1)
   kj=Text.GetSubText(jb,k,1)
   If ki="1" Or kj="1" Then
     kk="1"
   Else
     kk="0"
   EndIf
   If ki="1" And kj="1" Then
     kk="0"
   EndIf
   color=2*color+kk
 EndFor

EndSub

Sub Int2Bit 'n->ret

 x=n
 ret=""
 For k=1 to 8
   t=Math.Floor(x/2)
   r=Math.Remainder(x,2)
   ret=Text.Append(r,ret)
   x=t
 EndFor

EndSub </lang>

Output:

Munching squares - SmallBasic

OCaml

<lang ocaml>open Graphics

let () =

 open_graph "";
 resize_window 256 256;
 for y = 0 to pred (size_y()) do
   for x = 0 to pred (size_x()) do
     let v = (x lxor y) land 0xFF in
     set_color (rgb v (255 - v) 0);
     plot x y
   done;
 done;
 ignore(read_key())</lang>

Run with:

$ ocaml graphics.cma xor_pattern.ml

Output:

Octave

<lang Octave>size = 256; [x,y] = meshgrid([0:size-1]);

c = bitxor(x,y);

colormap(jet(size)); image(c); axis equal;</lang>

Output:

Perl

<lang perl>use GD;

my $img = new GD::Image(256, 256, 1);

for my $y(0..255) {

       for my $x(0..255) {
               my $color = $img->colorAllocate( abs(255 - $x - $y),  (255-$x) ^ $y , $x ^ (255-$y));
               $img->setPixel($x, $y, $color);
       }

}

print $img->png</lang>

Output:

Perl 6

Here's one simple way:

<lang perl6>my $ppm = open("munching0.ppm", :w) orelse .die;

$ppm.print(q :to 'EOT'); P3 256 256 255 EOT

for 0 .. 255 -> $row {

   for 0 .. 255 -> $col {
       my $color = $row +^ $col;
       $ppm.print("0 $color 0 ");
   }
   $ppm.say();

}

$ppm.close(); </lang>

Another way:

<lang perl6>my @colors = map -> $r, $g, $b { Buf.new: $r, $g, $b }, map -> $x { floor ($x/256) ** 3 * 256 }, (flat (0...255) Z (255...0) Z flat (0,2...254),(254,252...0));

my $PPM = open "munching1.ppm", :w orelse .die;

$PPM.print: qq:to/EOH/;

   P6
   # munching.pgm
   256 256 
   255
   EOH

$PPM.write: @colors[$_] for ^256 X+^ ^256;

$PPM.close;</lang>

Phix

Library: pGUI

<lang Phix>-- demo\rosetta\Munching_squares.exw include pGUI.e

Ihandle dlg, canvas cdCanvas cddbuffer, cdcanvas

function redraw_cb(Ihandle /*ih*/, integer /*posx*/, integer /*posy*/) integer {width, height} = IupGetIntInt(canvas, "DRAWSIZE")

   cdCanvasActivate(cddbuffer)
   for y=0 to height-1 do
       for x=0 to width-1 do
           cdCanvasPixel(cddbuffer, x, y, xor_bits(x,y))
       end for
   end for
   cdCanvasFlush(cddbuffer)
   return IUP_DEFAULT

end function

function map_cb(Ihandle ih)

   cdcanvas = cdCreateCanvas(CD_IUP, ih)
   cddbuffer = cdCreateCanvas(CD_DBUFFER, cdcanvas)
   cdCanvasSetBackground(cddbuffer, CD_WHITE)
   cdCanvasSetForeground(cddbuffer, CD_RED)
   return IUP_DEFAULT

end function

function esc_close(Ihandle /*ih*/, atom c)

   if c=K_ESC then return IUP_CLOSE end if
   return IUP_CONTINUE

end function

procedure main()

   IupOpen()
   
   canvas = IupCanvas(NULL)
   IupSetAttribute(canvas, "RASTERSIZE", "250x250")
   IupSetCallback(canvas, "MAP_CB", Icallback("map_cb"))

   dlg = IupDialog(canvas)
   IupSetAttribute(dlg, "TITLE", "Munching squares")
   IupSetAttribute(dlg, "RESIZE", "NO")
   IupSetCallback(dlg, "K_ANY",     Icallback("esc_close"))
   IupSetCallback(canvas, "ACTION", Icallback("redraw_cb"))

   IupMap(dlg)
   IupShowXY(dlg,IUP_CENTER,IUP_CENTER)
   IupMainLoop()
   IupClose()

end procedure

main()</lang>

PHP

<lang php>header("Content-Type: image/png");

$w = 256; $h = 256;

$im = imagecreate($w, $h)

   or die("Cannot Initialize new GD image stream");

$color = array(); for($i=0;$i<256;$i++) {

       array_push($color,imagecolorallocate($im,sin(($i)*(2*3.14/256))*128+128,$i/2,$i));

}

for($i=0;$i<$w;$i++) {

       for($j=0;$j<$h;$j++)
       {
               imagesetpixel($im,$i,$j,$color[$i^$j]);
       }

}

imagepng($im); imagedestroy($im);</lang>

Output:

PL/I

<lang PL/I>munch: procedure options (main); /* 21 May 2014 */

  declare screen (0:255, 0:255) bit(24) aligned;
  declare b bit(8) aligned;
  declare (x, y) unsigned fixed binary (8);

  do x = 0 upthru hbound(screen,2);
     do y = 0 upthru hbound(screen,1);
        b = unspec(x) ^ unspec(y);
        screen(x,y) = b;
     end;
  end;
  call writeppm(screen);

end munch;</lang>

Prolog

Works with SWI-Prolog and his GUI XPCE. <lang Prolog>xor_pattern :- new(D, window('XOR Pattern')), send(D, size, size(512,512)), new(Img, image(@nil, width := 512, height := 512 , kind := pixmap)),

forall(between(0,511, I), ( forall(between(0,511, J), ( V is I xor J, R is (V * 1024) mod 65536, G is (65536 - V * 1024) mod 65536, ( V mod 2 =:= 0 -> B is (V * 4096) mod 65536 ; B is (65536 - (V * 4096)) mod 65536), send(Img, pixel(I, J, colour(@default, R, G, B))))))),

new(Bmp, bitmap(Img)), send(D, display, Bmp, point(0,0)), send(D, open). </lang>

PureBasic

<lang purebasic>#palletteSize = 128 Procedure.f XorPattern(x, y) ;compute the gradient value from the pixel values

 Protected result = x ! y
 ProcedureReturn Mod(result, #palletteSize) / #palletteSize

EndProcedure

Procedure drawPattern()

 StartDrawing(ImageOutput(0))
   DrawingMode(#PB_2DDrawing_Gradient)
   CustomGradient(@XorPattern())
   ;specify a gradient pallette from which only specific indexes will be used
   For i = 1 To #palletteSize 
     GradientColor(1 / i, i * $BACE9B) ; or alternatively use $BEEFDEAD
   Next 
   Box(0, 0, ImageWidth(0), ImageHeight(0))
 StopDrawing()

EndProcedure

If OpenWindow(0, 0, 0, 128, 128, "XOR Pattern", #PB_Window_SystemMenu)

 CreateImage(0, WindowWidth(0), WindowHeight(0))
 drawPattern()
 ImageGadget(0, 0, 0, ImageWidth(0), ImageHeight(0), ImageID(0))
 Repeat
   event = WaitWindowEvent(20)
 Until event = #PB_Event_CloseWindow

EndIf</lang>

Python

Library: PIL

<lang Python>import Image, ImageDraw

image = Image.new("RGB", (256, 256)) drawingTool = ImageDraw.Draw(image)

for x in range(256):

   for y in range(256):
       drawingTool.point((x, y), (0, x^y, 0))

del drawingTool image.save("xorpic.png", "PNG")</lang>

Racket

lang racket

(require racket/draw) (define palette (for/vector ([x 256]) (make-object color% 0 0 x))) (define bm (make-object bitmap% 256 256)) (define dc (new bitmap-dc% [bitmap bm])) (for* ([x 256] [y 256])

 (define c (vector-ref palette (bitwise-xor x y)))
 (send dc set-pixel x y c))

bm </lang>

REXX

Translation of: Burlesque

<lang rexx>/*REXX program renders a graphical pattern by coloring each pixel with x XOR y */ /*───────────────────────────────────────── from an arbitrary constructed color table. */ rows=25 /*the number of rows in the color table*/ cols=50 /* " " " cols " " " " */

      do row  =0 for rows*3                     /*construct a color table, size  25x50.*/
        do col=0 for cols*3
                            $= (row+col) // 255
        @.row.col= x2b( d2x($+0, 2) ) ||,       /*ensure $ is converted──►2 hex nibbles*/
                   x2b( d2x($+1, 2) ) ||,
                   x2b( d2x($+2, 2) )
        end   /*col*/                           /* [↑]  construct a three-byte pixel.  */
      end     /*row*/

      do   x=0  for cols                        /*create a graphical pattern with XORs.*/
        do y=0  for rows
        @.x.y=bitxor(@.x, @.y)                  /*renders 3 bytes (a pixel) at a time. */
        end   /*y*/
      end     /*x*/
                                                /*stick a fork in it,  we're all done. */</lang>

Must be converted to an image with a separate program.

Ring

Project : Munching squares

load "guilib.ring"

paint = null

new qapp

       {
       win1 = new qwidget() {
                 setwindowtitle("Archimedean spiral")
                 setgeometry(100,100,500,600)
                 label1 = new qlabel(win1) {
                             setgeometry(10,10,400,400)
                             settext("")
                 }
                 new qpushbutton(win1) {
                         setgeometry(150,500,100,30)
                         settext("draw")
                         setclickevent("draw()")
                 }
                 show()
       }
       exec()
       }

func draw

       p1 = new qpicture()
              color = new qcolor() {
              setrgb(0,0,255,255)
       }
       pen = new qpen() {
                setcolor(color)
                setwidth(1)
       }
       paint = new qpainter() {
                 begin(p1)
                 setpen(pen)

       w = 100
       for x = 0 to w
            for y = 0 to w
                  b = (x ^ y)
                  color = new qcolor()
                  color.setrgb(255 -b,b /2,b,255)
                  pen.setcolor(color) 
                  setpen(pen)    
                  drawpoint(x,w -y -1)
            next
        next

       endpaint()
       }
       label1 { setpicture(p1) show() }
       return

</lang> Output:

https://www.dropbox.com/s/wvdqyihtxralviz/Squares.jpg?dl=0

Ruby

Uses Raster graphics operations/Ruby

<lang ruby>load 'raster_graphics.rb'

class Pixmap

 def self.xor_pattern(width, height, rgb1, rgb2)
   # create colour table
   size = 256
   colours = Array.new(size) do |i|
     RGBColour.new(
       (rgb1.red + (rgb2.red - rgb1.red) * i / size), 
       (rgb1.green + (rgb2.green - rgb1.green) * i / size), 
       (rgb1.blue + (rgb2.blue - rgb1.blue) * i / size), 
     )
   end

   # create the image
   pixmap = new(width, height)
   pixmap.each_pixel do |x, y|
     pixmap[x,y] = colours[(x^y)%size]
   end
   pixmap
 end

end

img = Pixmap.xor_pattern(384, 384, RGBColour::RED, RGBColour::YELLOW) img.save_as_png('xorpattern.png')</lang>

Run BASIC

<lang runbasic>w = 100 graphic #g, w,w for x = 0 to w

 for y = 0 to w
   b = (x xor y) and 255
   #g color(255 -b,b /2,b)
   #g "set "; x; " "; w -y -1
 next y

next x render #g

g "flush"</lang>

Rust

<lang rust>extern crate image;

use image::{ImageBuffer, Pixel, Rgb};

fn main() {

   let mut img = ImageBuffer::new(256, 256);

   for x in 0..256 {
       for y in 0..256 {
           let pixel = Rgb::from_channels(0, x as u8 ^ y as u8, 0, 0);
           img.put_pixel(x, y, pixel);
       }
   }

   let _ = img.save("output.png");

}</lang>

Scala

Scala Swing

Library: org.scala-lang.modules scala-swing

<lang Scala>import scala.swing.Swing.pair2Dimension import scala.swing.{Color, Graphics2D, MainFrame, Panel, SimpleSwingApplication}

object XorPattern extends SimpleSwingApplication {

 def top = new MainFrame {
   preferredSize = (300, 300)
   title = "Rosetta Code >>> Task: Munching squares | Language: Scala"
   contents = new Panel {

     protected override def paintComponent(g: Graphics2D) = {
       super.paintComponent(g)
       for {
         y <- 0 until size.getHeight.toInt
         x <- 0 until size.getWidth.toInt
       } {
         g.setColor(new Color(0, (x ^ y) % 256, 0))
         g.drawLine(x, y, x, y)
       }
     }
   }

   centerOnScreen()
 }

}</lang>

Sidef

Translation of: Perl

<lang ruby>require('Imager')

var img = %O<Imager>.new(xsize => 256, ysize => 256)

for y=(^256), x=(^256) {

   var rgb = [(255 - x - y).abs, (255-x)^y, x^(255-y)]
   img.setpixel(x => x, y => y, color => rgb)

}

img.write(file => 'xor.png')</lang> Output image: Munching squares

Tcl

Library: Tk

<lang tcl>package require Tk

proc xorImage {img table} {

   set data {}
   set h [image height $img]
   set w [image width $img]
   for {set y 0} {$y < $h} {incr y} {

set row {} for {set x 0} {$x < $w} {incr x} { lappend row [lindex $table [expr {($x^$y) % [llength $table]}]] } lappend data $row

   }
   $img put $data

} proc inRange {i f t} {expr {$f + ($t-$f)*$i/255}} proc mkTable {rf rt gf gt bf bt} {

   for {set i 0} {$i < 256} {incr i} {

lappend tbl [format "#%02x%02x%02x" \ [inRange $i $rf $rt] [inRange $i $gf $gt] [inRange $i $bf $bt]]

   }
   return $tbl

}

set img [image create photo -width 512 -height 512] xorImage $img [mkTable 0 255 64 192 255 0] pack [label .l -image $img]</lang>

TI-83 BASIC

Due to the TI-83's 1 bit black and white display, this program uses the home screen and a gradient of characters. Since the TI-83 does not use a standard encoding, the first Sto→ to Str1 may be subjectively interpreted.

<lang ti-83b>PROGRAM:XORPATT " •.-,+-°-1+o*:πOX"→Str1

ClrHome

{0,0,0,0}→L1 {0,0,0,0)→L2

For(I,1,8,1) For(J,1,16,1) J→A I→B

If A>8 Then A-8→A 1→L1(1) Else 0→L1(1) End

If A>4 Then A-4→A 1→L1(2) Else 0→L1(2) End

If A>2 Then A-2→A 1→L1(3) Else 0→L1(3) End

If A>1 Then 1→L1(4) Else 0→L1(4) End

0→L2(1)

If B>4 Then B-4→B 1→L2(2) Else 0→L2(2) End

If B>2 Then B-2→B 1→L2(3) Else 0→L2(3) End

If B>1 Then 1→L2(4) Else 0→L2(4) End

L1≠L2→L3 8L3(1)+4L3(2)+2L3(3)+L3(4)→C Output(I,J,sub(Str1,C+1,1))

End End Pause </lang>

Visual Basic .NET

Works with: Visual Basic .NET version 2011

<lang vbnet>' Munching squares - 27/07/2018 Public Class MunchingSquares

   Const xsize = 256
   Dim BMP As New Drawing.Bitmap(xsize, xsize)
   Dim GFX As Graphics = Graphics.FromImage(BMP)

   Private Sub MunchingSquares_Paint(sender As Object, e As PaintEventArgs) Handles Me.Paint
       'draw
       Dim MyGraph As Graphics = Me.CreateGraphics
       Dim nColor As Color
       Dim i, j, cp As Integer
       xPictureBox.Image = BMP
       For i = 0 To xsize - 1
           For j = 0 To xsize - 1
               cp = i Xor j
               nColor = Color.FromArgb(cp, 0, cp)
               BMP.SetPixel(i, j, nColor)
           Next j
       Next i
   End Sub 'Paint

End Class </lang>

Output:

Munching squares - vbnet

XPL0

<lang XPL0>include c:\cxpl\codes; \intrinsic 'code' declarations int X, Y; [SetVid($101); \set 640x480 graphics with 8-bit color port($3C8):= 0; \set color registers with beautiful shades for X:= 0 to 256-1 do

       [port($3C9):= X>>1;     \red
        port($3C9):= X>>3;     \green
        port($3C9):= X;        \blue
        ];

for Y:= 0 to 256-1 do \"color table" is array of 256 registers

   for X:= 0 to 256-1 do
       Point(X, Y, X|Y);       \"|" = XOR, not OR which is "!"

X:= ChIn(1); \wait for keystroke SetVid(3); \restore normal text mode ]</lang>

Output:

Yabasic

Translation of: FreeBASIC

<lang Yabasic>w = 256

open window w, w

For x = 0 To w-1

   For y = 0 To w-1
       r =and(xor(x, y), 255)
       color r, r, r
       dot x, y
   Next

Next</lang>

zkl

Uses the PPM class from http://rosettacode.org/wiki/Bitmap/Bresenham%27s_line_algorithm#zkl

Translation of: XPL0

For a kaleidoscopic image, play with coolness. <lang zkl>fcn muncher{

  bitmap:=PPM(256,256);
  coolness:=(1).random(0x10000);  // 55379, 18180, 40, 51950, 57619, 43514, 65465
  foreach y,x in ([0 .. 255],[0 .. 255]){
     b:=x.bitXor(y);	// shades of blue

// rgb:=b*coolness; // kaleidoscopic image // rgb:=(b*coolness + b)*coolness + b; // more coolness

     rgb:=(b*0x10000 + b)*0x10000 + b;  // copy ADA image
     bitmap[x,y]=rgb;
  }
  bitmap.write(File("foo.ppm","wb"));

}();</lang> For a cheap slide show (on Linux): <lang zkl>while(1){ muncher(); Atomic.sleep(3); }</lang> run ImageViewer on foo.ppm and watch it [auto] update as the image changes.

Output:

Same as the ADA image: