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