Illustration of bit depth

bitdepth.pde

int stepW, stepH;
color colA = color(255,0,0);
color colB = color(0,0,255);
color fillCol = colA;

int numRows = 5;

void setup() {
  size(1024, 768, P2D);
  noStroke();
  stepH = height/numRows;
}

void draw() {
   for (int i=0; i<numRows; i++) {
     drawLines(i, i*2+2);
   }
}

void drawLines(int y, int exp) {
  stepW = width / (int) pow(2, exp);

  for (int i=0; i<width; i++) {
    fillCol = colA;
    if (i %2 == 0) fillCol = colB;
    fill(fillCol);
    rect(i*stepW, y*stepH, stepW, stepH); 
  }
}

void keyPressed() {
  saveFrame("output.png");
}