We have a pdf invoices with totals displaying both prices with included and excluded tax, but without a subtotal. What we need now only on pdf invoices is to display a total when the discount (coupon code) is active. I see that this works, but not on the totals itself:
$subtotal = $item->getRowTotal() + $item->getTaxAmount() + $item->getHiddenTaxAmount() - $item->getDiscountAmount();
What would be the proper way of showing this total line on PDF invoices?