Incremental Grid

  // Incremental Grid
  
  void setup()
  {
    size(500,500);
    noStroke();
  }
  
  void draw()
  {
    int gridWidth = 25;
    int cellWidth = width/gridWidth;
    int n = 0;
    scale(cellWidth);
    for (int y = 0; y < gridWidth; ++y) {
      for (int x = 0; x < gridWidth; ++x) {
        fill( map(sin( millis()*.00001*n ),-1,1,0,255) );
        rect( x, y, 1, 1 );
        ++n;
      }
    }
  }