public function brush($x, $y, $color = 'black', $shape = 'square')
{
switch ($shape) {
case 'triangle':
$verts[0] = array('x' => $x + 3, 'y' => $y + 3);
$verts[1] = array('x' => $x, 'y' => $y - 3);
$verts[2] = array('x' => $x - 3, 'y' => $y + 3);
$this->polygon($verts, $color, $color);
break;
case 'circle':
$this->circle($x, $y, 3, $color, $color);
break;
case 'diamond':
$verts[0] = array('x' => $x - 3, 'y' => $y);
$verts[1] = array('x' => $x, 'y' => $y + 3);
$verts[2] = array('x' => $x + 3, 'y' => $y);
$verts[3] = array('x' => $x, 'y' => $y - 3);
$this->polygon($verts, $color, $color);
break;
case 'square':
default:
$this->rectangle($x - 2, $y - 2, 4, 4, $color, $color);
break;
}
}