Drawing Figures with Loops - Diamond

$num = intval(readline());
echo str_repeat("-", ($num - 1) / 2) . str_repeat("*", $num & 1 ? 1 : 2) . str_repeat("-", ($num - 1) / 2) . "\n";
for ($i = 1, $j = 0; $i < $num / 2; $i++, $j += 2) {
    echo str_repeat("-", (($num - 1) / 2) - $i) . "*" . str_repeat("-", ($num & 1 ? 1 : 2) + $j) . "*" . str_repeat("-", (($num - 1) / 2) - $i) . "\n";
}
for ($i = 1, $j = 0; $i <= ($num - 3) / 2; $i++, $j += 2) {
    echo str_repeat("-", $i) . "*" . str_repeat("-", round($num - 4) - $j) . "*" . str_repeat("-", $i) . "\n";
}
if ($num != 1 && $num != 2) {
    echo str_repeat("-", ($num - 1) / 2) . str_repeat("*", $num & 1 ? 1 : 2) . str_repeat("-", ($num - 1) / 2);
}