float box_size = 11; float box_space = 12; int margin = 7; size(200, 200); background(0); noStroke(); // Draw gray boxes for (int i = margin; i < height-margin; i += box_space){ if(box_size > 0){ for(int j = margin; j < width-margin; j+= box_space){ fill(255-box_size*10); rect(j, i, box_size, box_size); } box_size = box_size - 0.6; } }