gistfile1.txt

/*
↓参考
http://saeki-ce.xsrv.jp/C_src/mandelbrot01.html
↓あとで読む
http://azisava.sakura.ne.jp/mandelbrot/algorithm.html
*/

int windowX = 800, windowY = 800;
double cr1 = -2.3, cr2 = 0.7;
double ci1 = -1.5, ci2 = 1.5;
double e = 4.0;
int imax = 400;

void setup(){
 size(windowX, windowY);
 
}

void draw(){
  background(0);
  double cr,ci,dcr,dci;
  double zr,zi,zrn,zin;
  int i,ix,iy,cl,nc;
  char[] c = new char[128];
  
  dcr=(cr2-cr1)/windowY;
  dci=(ci2-ci1)/windowX;
  nc=imax/256;
  for(ci=ci1,iy=windowX; ci<=ci2; ci+=dci+=dci,iy--){
    for(cr=cr1,ix=0; cr<=cr2; cr+=dcr,ix++){
      zr=0.0; zi=0.0;
      for(i=0; i<imax; i++){
        zrn=zr*zr-zi*zi+cr;
        if(zrn>e) break;
        zin=2.0*zr*zi+ci;
        if(zin>e) break;
        
        zr=zrn; zi=zin;
      }
      
      cl=i/nc;
      if(cl>255) cl=255;
      fill(color(cl,cl,cl));
      print(ix +","+ iy);
      point(ix,iy);
    }
  }
  
}