ResizeCanvas.php

<?php
    /**
##DOC-SIGNATURE##

    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
  **/

namespace WideImage\Operation;

use WideImage\WideImage;
use WideImage\Coordinate;

/**
 * ResizeCanvas operation class
 *
 * @package Internal/Operations
 */
class ResizeCanvas
{
    /**
     * Returns an image with a resized canvas
     *
     * The image is filled with $color. Use $scale to determine, when to resize.
     *
     * @param \WideImage\Image $img
     * @param smart_coordinate $width
     * @param smart_coordinate $height
     * @param smart_coordinate $left
     * @param smart_coordinate $top
     * @param int $color
     * @param string $scale 'up', 'down', 'any'
     * @param boolean $merge
     * @return \WideImage\Image
     */
    public function execute($img, $width, $height, $left, $top, $color, $scale, $merge)
    {
        $new_width  = Coordinate::fix($width, $img->getWidth());
        $new_height = Coordinate::fix($height, $img->getHeight());
        
        if ($scale == 'down') {
            $new_width  = min($new_width, $img->getWidth());
            $new_height = min($new_height, $img->getHeight());
        } elseif ($scale == 'up') {
            $new_width  = max($new_width, $img->getWidth());
            $new_height = max($new_height, $img->getHeight());
        }
        
        $new = WideImage::createTrueColorImage($new_width, $new_height);
        
        if ($img->isTrueColor()) {
            if ($color === null) {
                $color = $new->allocateColorAlpha(0, 0, 0, 127);
            }
        } else {
            imagepalettecopy($new->getHandle(), $img->getHandle());
            
            if ($img->isTransparent()) {
                $new->copyTransparencyFrom($img);
                $tc_rgb  = $img->getTransparentColorRGB();
                $t_color = $new->allocateColorAlpha($tc_rgb);
            }
            
            if ($color === null) {
                if ($img->isTransparent()) {
                    $color = $t_color;
                } else {
                    $color = $new->allocateColorAlpha(255, 0, 127, 127);
                }
                
                imagecolortransparent($new->getHandle(), $color);
            }
        }
        
        $new->fill(0, 0, $color);
        
        $x = Coordinate::fix($left, $new->getWidth(), $img->getWidth());
        $y = Coordinate::fix($top, $new->getHeight(), $img->getHeight());
        
        // blending for truecolor images
        if ($img->isTrueColor()) {
            $new->alphaBlending($merge);
        }
        
        // not-blending for palette images
        if (!$merge && !$img->isTrueColor() && isset($t_color)) {
            $new->getCanvas()->filledRectangle($x, $y, $x + $img->getWidth(), $y + $img->getHeight(), $t_color);
        }
        
        $img->copyTo($new, $x, $y);
        
        return $new;
    }
}