PHP to add a watermark to the picture

Public function water ($filename, $water, $pos =0, $pct =80) {
Load watermark Picture
$info = $this->getimageinfo ($water);
if (!empty ($info [0])) {
$water _w = $info [0];
$water _h = $info [1];
$type = $info [' type '];
$fun = ' imagecreatefrom '. $type;
$waterimg = $fun ($water);
} else{
return false;
}
Load background picture
$info = $this->getimageinfo ($this->img);
if (!empty ($info [0])) {
$old _w = $info [0];
$old _h = $info [1];
$type = $info [' type '];
$fun = ' imagecreatefrom '. $type;
$oldimg = $fun ($this->img);
} else{
return false;
}
Clipping watermark
$water _w > $old _w && $water _w = $old _w;
$water _h > $old _h && $water _h = $old _h;

Watermark Location
Switch ($pos) {
Case 0://Random
$posX = rand (0, $old _w-$water _w));
$posY = rand (0, $old _h-$water _h));
Break
Case 1://1 for top left
$posX = 0;
$posY = 0;
Break
Case 2://2 for top center
$posX = ($old _w-$water _w)/2;
$posY = 0;
Break
Case 3://3 for top right
$posX = $old _w-$water _w;
$posY = 0;
Break
Case 4://4 for Central left
$posX = 0;
$posY = ($old _h-$water _h)/2;
Break
Case 5://5 centered in middle
$posX = ($old _w-$water _w)/2;
$posY = ($old _h-$water _h)/2;
Break
Case 6://6 for Middle right
$posX = $old _w-$water _w;
$posY = ($old _h-$water _h)/2;
Break
Case 7://7 to bottom left
$posX = 0;
$posY = $old _h-$water _h;
Break
Case 8://8 centered at bottom
$posX = ($old _w-$water _w)/2;
$posY = $old _h-$water _h;
Break
Case 9://9 to bottom right
$posX = $old _w-$water _w;
$posY = $old _h-$water _h;
Break
Default://Random
$posX = rand (0, $old _w-$water _w));
$posY = rand (0, $old _h-$water _h));
Break
}
Set the blending mode of the image
Imagealphablending ($oldimg, true);
Add watermark
Imagecopymerge ($oldimg, $waterimg, $posX, $posY, 0, 0, $water _w, $water _h, $pct);
$fun = ' image '. $type;
!@ $fun ($oldimg, $filename, MB) && die (' Save failed! ') check if directory exists and writable? '
Imagedestroy ($OLDIMG);
Imagedestroy ($WATERIMG);
return $filename;
       }