/**
 * A simple brush.
 *
 * <p>Elie Zananiri<br>
 * CART 253, Winter 2008</p>
 */
 
int brushSize = 20;

void setup() {
  size(400, 400);
  smooth();
  
  noStroke();
  background(255);
}

void draw() {
  if (mousePressed) {
    brush(mouseX, mouseY);
  }
}

void brush(int x, int y) {
  fill(#CC3300);
  arc(x, y, brushSize, brushSize, 0, PI);
  fill(#003333);
  arc(x, y, brushSize, brushSize, PI, TWO_PI);
}