// Dartmouth CS 2, Winter 2009, Chris Bailey-Kellogg
// Notes 5 | Sketch 4

void setup()
{
  size(400,400);
  fill(0,50);  // default to transparent black
  noStroke();
  background(0);
}

void draw()
{
  ellipse(mouseX,mouseY,10,10);
}

void keyPressed()
{
  // Set fill color to be red, green, blue, or black
  // according to key press
  if (key=='r') fill(255,0,0,50);
  else if (key=='g') fill(0,255,0,50);
  else if (key=='b') fill(0,0,255,50);
  else fill(0,50);
}