Stop other products from being discounted

[crackq]

I have below code which calculate the discount of all products but now i want to stop other product to get discounted , please help. thank you.

public function calculateItemDiscount(
$item,
$total,
$totalDiscount,
&$base


----------


Discount,
&$discount,
$isCalculateTax,
&$lastItem
) {
$itemBaseDiscount = ($this->getItemTotalForDiscount($item, $isCalculateTax, false) / $total) * $totalDiscount;
$itemBaseDiscount = $this->round($itemBaseDiscount, 'base');
$itemDiscount = $this->convertPrice($itemBaseDiscount, false, false, $item->getStoreId());
$itemDiscount = $this->round($itemDiscount);
$item->setBaseAffiliateDiscountAmount($item->getBaseAffiliateDiscountAmount() + $itemBaseDiscount)
->setAffiliateDiscountAmount($item->getAffiliateDiscountAmount() + $itemDiscount);
$baseDiscount += $itemBaseDiscount;
$discount += $itemDiscount;
$lastItem = $item;
}