float lightfield[][] = new float[800][240];
float cx,cy;
int range;

void setup(){
  size(800,240);
  rectMode(CENTER);
  noStroke();
  float lx, ly,lr;
  cx=0.0;
  cy=0.0;
  range=0;
  framerate(20);
  for (int x=0;x<800;x++){
    for (int y=0;y<240;y++){
      lightfield[int(x)][int(y)]=0;
    }
  }
  for (int i = 0;i<100;i++){
    lx=random(800);
    ly =random(240);
    lr=random(10.0);
    for (int x=0;x<800;x++){
      for (int y=0;y<240;y++){
        lightfield[int(x)][int(y)]+=5000/sq(max(1.0,dist(lx,ly,x,y)-lr)); 
      }
    }
  }
}

void draw(){
  updatemouse();
  int x1 =constrain(int(cx),0,799);
  int y1 =constrain(int(cy),0,239);

  for (float s=1.0;s>0.01;s/=2.0){
    for (int i=0-range;i<6+2*range;i++){
      for (int j=0-range;j<6+2*range;j++){
        colorrect(x1-800*s+i*320*s,y1-800*s+j*320*s,320*s,320*s);
      }
    }
  }



  for (int i=0-range;i<6+2*range;i++){
    for (int j=0-range;j<6+2*range;j++){
      monocrect(x1-6.25+i*2.5,y1-6.25+j*2.5,2.5,2.5);
    }
  }

  for (int i=0-range;i<6+2*range;i++){
    for (int j=0-range;j<6+2*range;j++){
      monocrect(x1-3.125+i*1.25,y1-3.125+j*1.25,1.25,1.25);
    }
  }





}


void colorrect(float mx, float my, float w, float h){
  int c=min(255,int(lightfield[int(constrain(mx,0,799))][int(constrain(my,0,239))]));
  if((c>50)&&(c<70)){
    fill(c+100,c,c);
  }
  else{
    fill(c);
  }

  rect(mx,my,w,h);

}

void monocrect(float mx, float my, float w, float h){
  int c=min(255,int(lightfield[int(constrain(mx,0,799))][int(constrain(my,0,239))]));
  fill(c);


  rect(mx,my,w,h);

}


void updatemouse(){

  cx=0.9*cx+0.1*mouseX;
  cy=0.9*cy+0.1*mouseY;

}