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<?php
/**
* Imageblendedcolorallocate v1.0.1
*
* Copyright (c) 2018 Andrew G. Johnson <andrew@andrewgjohnson.com>
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in the
* Software without restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
* Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* PHP version 5
*
* @category Andrewgjohnson
* @package Imageblendedcolorallocate
* @author Andrew G. Johnson <andrew@andrewgjohnson.com>
* @copyright 2018 Andrew G. Johnson <andrew@andrewgjohnson.com>
* @license https://opensource.org/licenses/mit/ The MIT License
* @link https://github.com/andrewgjohnson/imageblendedcolorallocate
*/
if (!function_exists('imageblendedcolorallocate')) {
/**
* Imageblendedcolorallocate is a function that will allocate a new blended
* color based on two existing allocated colors for your PHP GD images.
*
* @param resource $image <p>An image resource, returned by one of the
* image creation functions, such as imagecreatetruecolor().</p>
* @param int $color1 <p>A color identifier created with
* imagecolorallocate().</p>
* @param int $color2 <p>A color identifier created with
* imagecolorallocate().</p>
* @param double $opacityColor1 <p>A value between 0 and 1. 1 indicates
* completely opaque while 0 indicates completely transparent.</p>
*
* @return mixed Returns a color identifier or FALSE if the allocation failed.
*/
function imageblendedcolorallocate(
$image,
$color1,
$color2,
$opacityColor1 = 0.5
) {
if ($opacityColor1 >= 0 && $opacityColor1 <= 1) {
$opacityColor2 = 1 - $opacityColor1;
} else {
$opacityColor1 = $opacityColor2 = 0.5;
}
$redColor1 = ($color1 >> 16) & 0xFF;
$redColor2 = ($color2 >> 16) & 0xFF;
$red = $redColor1 * $opacityColor1;
$red += $redColor2 * $opacityColor2;
$red = round($red);
$greenColor1 = ($color1 >> 8) & 0xFF;
$greenColor2 = ($color2 >> 8) & 0xFF;
$green = $greenColor1 * $opacityColor1;
$green += $greenColor2 * $opacityColor2;
$green = round($green);
$blueColor1 = $color1 & 0xFF;
$blueColor2 = $color2 & 0xFF;
$blue = $blueColor1 * $opacityColor1;
$blue += $blueColor2 * $opacityColor2;
$blue = round($blue);
$alphaColor1 = imagecolorsforindex($image, $color1)['alpha'];
$alphaColor2 = imagecolorsforindex($image, $color2)['alpha'];
$alpha = $alphaColor1 * $opacityColor1;
$alpha += $alphaColor2 * $opacityColor2;
$alpha = round($alpha);
if ($alpha > 0) {
return imagecolorallocatealpha($image, $red, $green, $blue, $alpha);
} else {
return imagecolorallocate($image, $red, $green, $blue);
}
}
}