Image:Aliased.png

Aliased chessboard

Created with a variant of this program, which I (Loisel 03:56 Jan 24, 2003 (UTC)) wrote myself:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <assert.h>
int color(double x, double y)
{
  double t,z;
  int i,j,k;

  x=x/128.0-0.5;
  y=y/1024.0;

  t=1.0/(y+0.01);
  z=t*x;
  i=floor(t);
  j=floor(z);
  k=i+j;
  /*  printf("%f %f -> %i %i %i\n",t,z,i,j,k%2); */
  return ((k%2)!=0);
}

double myrand()
{
  return rand()/((double)RAND_MAX);
}

int main()
{
  int i,j,k,l;
  double x,y;
  printf("P5\n128 128\n255\n");
  srand(time(0));
  for(i=0;i<128;i++)
    for(j=0;j<128;j++)
      {
 k=0;
 for(l=0;l<255;l++)
   {
     x=j+myrand();
     y=i+myrand();
     k+=color(x,y);
   }
 assert(k>=0 && k<=255);
 k=(k/4)*4; /* cygwin bug? */
 fwrite(&k,1,1,stdout);
      }
}

Originally from en.wikipedia; description page is/was here.

2003-01-24 (first version); 2007-09-15 (last version)

Original uploader was Loisel at en.wikipedia Later versions were uploaded by Riumplus, AzaToth, Dicklyon at en.wikipedia.

Licensed under the GFDL by the author; Released under the GNU Free Documentation License.