<?php /** * @author Gasper Kozak * @copyright 2007-2011 This file is part of WideImage. WideImage is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. WideImage is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with WideImage; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * @package Internal/Operations **/ /** * GetMask operation class * * @package Internal/Operations */ class WideImage_Operation_GetMask { /** * Returns a mask * * @param WideImage_Image $image * @return WideImage_Image */ function execute($image) { $width = $image->getWidth(); $height = $image->getHeight(); $mask = WideImage_TrueColorImage::create($width, $height); $mask->setTransparentColor(-1); $mask->alphaBlending(false); $mask->saveAlpha(false); for ($i = 0; $i <= 255; $i++) $greyscale[$i] = ImageColorAllocate($mask->getHandle(), $i, $i, $i); imagefilledrectangle($mask->getHandle(), 0, 0, $width, $height, $greyscale[255]); $transparentColor = $image->getTransparentColor(); $alphaToGreyRatio = 255 / 127; for ($x = 0; $x < $width; $x++) for ($y = 0; $y < $height; $y++) { $color = $image->getColorAt($x, $y); if ($color == $transparentColor) $rgba['alpha'] = 127; else $rgba = $image->getColorRGB($color); imagesetpixel($mask->getHandle(), $x, $y, $greyscale[255 - round($rgba['alpha'] * $alphaToGreyRatio)]); } return $mask; } }