note 71765 added to function.imagealphablending

I rewrote the code given below to skip calculations and pixel setting when not needed (full opaque or full transparent pixels), as the content of my overlays is generally mostly transparent. Reduced processing time from ~0.17s to ~0.06s on 216x145px images. function alphaOverlay($destImg, $overlayImg, $imgW, $imgH) { for($y=0;$y<$imgH;$y++) { for($x=0;$x<$imgW;$x++) { $ovrARGB = imagecolorat($overlayImg, $x, $y); $ovrA = ($ovrARGB >> 24) << 1; $ovrR = $ovrARGB >> 16 & 0xFF; $ovrG = $ovrARGB >> 8 & 0xFF; $ovrB = $ovrARGB & 0xFF; $change = false; if($ovrA == 0) { $dstR = $ovrR; $dstG = $ovrG; $dstB = $ovrB; $change = true; } elseif($ovrA < 254) { $dstARGB = imagecolorat($destImg, $x, $y); $dstR = $dstARGB >> 16 & 0xFF; $dstG = $dstARGB >> 8 & 0xFF; $dstB = $dstARGB & 0xFF; $dstR = (($ovrR * (0xFF-$ovrA)) >> 8) + (($dstR * $ovrA) >> 8); $dstG = (($ovrG * (0xFF-$ovrA)) >> 8) + (($dstG * $ovrA) >> 8); $dstB = (($ovrB * (0xFF-$ovrA)) >> 8) + (($dstB * $ovrA) >> 8); $change = true; } if($change) { $dstRGB = imagecolorallocatealpha($destImg, $dstR, $dstG, $dstB, 0); imagesetpixel($destImg, $x, $y, $dstRGB); } } } return $destImg; } ---- Server IP: 216.194.113.175 Probable Submitter: 207.173.178.2 (proxied: 207.173.178.102) ---- Manual Page -- http://www.php.net/manual/en/function.imagealphablending.php Edit -- https://master.php.net/note/edit/71765 Del: integrated -- https://master.php.net/note/delete/71765/integrated Del: useless -- https://master.php.net/note/delete/71765/useless Del: bad code -- https://master.php.net/note/delete/71765/bad+code Del: spam -- https://master.php.net/note/delete/71765/spam Del: non-english -- https://master.php.net/note/delete/71765/non-english Del: in docs -- https://master.php.net/note/delete/71765/in+docs Del: other reasons-- https://master.php.net/note/delete/71765 Reject -- https://master.php.net/note/reject/71765 Search -- https://master.php.net/manage/user-notes.php