protected function buildOctogonShape($squareSize)
{
$s = $squareSize;
$c = $s * 0.33;
$sMinusC = $s - $c;
return "{$c},0,{$sMinusC},0,{$s},{$c},{$s},{$sMinusC},{$sMinusC},{$s},{$c},{$s},0,{$sMinusC},0,{$c},{$c},0";
}