int WIDTH=500; //use even number
int HEIGHT=500;
int arrWIDTH=WIDTH;
int arrHEIGHT=HEIGHT;

int[] current=new int[arrWIDTH*arrHEIGHT];
int[] collision=new int[arrWIDTH*arrHEIGHT];
int[] collisonTable={
00,01,02,03,04,05,06,07,
010,022,012,013,014,015,016,017,
020,021,011,023,024,052,026,027,
030,031,032,033,034,035,036,037,
040,041,042,043,022,045,046,047,
050,051,025,053,054,055,056,057,
060,061,062,063,064,065,066,067,
070,071,072,073,074,075,076,077,
};
int[] collisonTableAlt={
00,01,02,03,04,05,06,07,
010,044,012,013,014,015,016,017,
020,021,044,023,024,052,026,027,
030,031,032,033,034,035,036,037,
040,041,042,043,011,045,046,047,
050,051,025,053,054,055,056,057,
060,061,062,063,064,065,066,067,
070,071,072,073,074,075,076,077,
};

int[] bitCount={
0,1,1,2,1,2,2,3,
1,2,2,3,2,3,3,4,
1,2,2,3,2,3,3,4,
2,3,3,4,3,4,4,5,
1,2,2,3,2,3,3,4,
2,3,3,4,3,4,4,5,
2,3,3,4,3,4,4,5,
3,4,4,5,4,5,5,6
};

void setup() 
{
  for(int i=0;i<arrWIDTH;i++)
  {
    for(int j=0;j<arrHEIGHT;j++)
    {
      if(i>arrWIDTH*2/5 & i<arrWIDTH*3/5 & j>arrHEIGHT*2/5 & j<arrHEIGHT*3/5)
        current[i*arrWIDTH+j]=63;
      else
        {
          current[i*arrWIDTH+j]=int(random(63)); 
          //current[i*arrWIDTH+j]=0;
        }
    }
  }
  
  size(WIDTH,HEIGHT);
  smooth();
  fill(255,0,0);
  noStroke();
  frameRate(30);
  background(0);
  
}

int iWrap(int i,int offset)
{
  return (i+offset+arrWIDTH)%arrWIDTH;
}
int jWrap(int j,int offset)
{
  return (j+offset+arrHEIGHT)%arrHEIGHT;
}

void draw()
{
  //collision
  int colFlag=1;
  for(int i=0;i<arrWIDTH;i++)
  {
    for(int j=0;j<arrHEIGHT;j++)
    {
      if (colFlag==1)
        collision[i*arrWIDTH+j]=collisonTable[current[i*arrWIDTH+j]];
      else
        collision[i*arrWIDTH+j]=collisonTableAlt[current[i*arrWIDTH+j]];
      if (random(1)>0.5) colFlag=colFlag*-1;
    }
  }
  //transport
  for(int i=0;i<arrWIDTH;i++)
  {
    for(int j=0;j<arrHEIGHT;j++)
    {
      if (j%2==1)
        current[i*arrWIDTH+j]=(collision[iWrap(i,-1)*arrWIDTH+jWrap(j,0)]&1)|
                              (collision[iWrap(i,0)*arrWIDTH+jWrap(j,1)]&2)|
                              (collision[iWrap(i,1)*arrWIDTH+jWrap(j,1)]&4)|
                              (collision[iWrap(i,1)*arrWIDTH+jWrap(j,0)]&8)|
                              (collision[iWrap(i,1)*arrWIDTH+jWrap(j,-1)]&16)|
                              (collision[iWrap(i,0)*arrWIDTH+jWrap(j,-1)]&32);
      else
        current[i*arrWIDTH+j]=(collision[iWrap(i,-1)*arrWIDTH+jWrap(j,0)]&1)|
                              (collision[iWrap(i,-1)*arrWIDTH+jWrap(j,1)]&2)|
                              (collision[iWrap(i,0)*arrWIDTH+jWrap(j,1)]&4)|
                              (collision[iWrap(i,1)*arrWIDTH+jWrap(j,0)]&8)|
                              (collision[iWrap(i,0)*arrWIDTH+jWrap(j,-1)]&16)|
                              (collision[iWrap(i,-1)*arrWIDTH+jWrap(j,-1)]&32);
    }
  }
  //if(frameCount%2==0)
  {
    loadPixels();
    //println(arrWIDTH);
    //println(arrHEIGHT);
    for(int i=0;i<arrWIDTH;i++)
    {
      for(int j=0;j<arrHEIGHT;j++)
      {
        int intensity=bitCount[current[i*arrWIDTH+j]];
        color c=color(255-(42*intensity),255-(42*intensity),255-(42*intensity));
        int ind=(i*WIDTH+j);
        pixels[ind]=c;
      }
    }
    updatePixels();
  }

}