272 lines
8.3 KiB
PHP
272 lines
8.3 KiB
PHP
<?php
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// $Id$
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/**
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* @file
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* API for manipulating images.
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*/
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/**
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* @defgroup image Image toolkits
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* @{
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* Drupal's image toolkits provide an abstraction layer for common image file
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* manipulations like scaling, cropping, and rotating. The abstraction frees
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* module authors from the need to support multiple image libraries, and it
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* allows site administrators to choose the library that's best for them.
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*
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* PHP includes the GD library by default so a GD toolkit is installed with
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* Drupal. Other toolkits like ImageMagic are available from contrib modules.
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* GD works well for small images, but using it with larger files may cause PHP
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* to run out of memory. In contrast the ImageMagick library does not suffer
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* from this problem, but it requires the ISP to have installed additional
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* software.
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*
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* Image toolkits are discovered based on the associated module's
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* hook_image_toolkits. Additionally the image toolkit include file
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* must be identified in the files array in the module.info file. The
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* toolkit must then be enabled using the admin/settings/image-toolkit
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* form.
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*
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* Only one toolkit may be selected at a time. If a module author wishes to call
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* a specific toolkit they can check that it is installed by calling
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* image_get_available_toolkits(), and then calling its functions directly.
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*/
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/**
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* Return a list of available toolkits.
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*
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* @return
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* An array of toolkit name => descriptive title.
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*/
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function image_get_available_toolkits() {
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// hook_image_toolkits returns an array of toolkit names.
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$toolkits = module_invoke_all('image_toolkits');
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$output = array();
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foreach ($toolkits as $name) {
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$function = 'image_' . $name . '_info';
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if (drupal_function_exists($function)) {
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$info = $function();
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$output[$info['name']] = $info['title'];
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}
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}
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return $output;
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}
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/**
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* Retrieve the name of the currently used toolkit.
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*
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* @return
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* String containing the name of the selected toolkit, or FALSE on error.
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*/
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function image_get_toolkit() {
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static $toolkit;
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if (!$toolkit) {
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$toolkit = variable_get('image_toolkit', 'gd');
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if (isset($toolkit) &&
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drupal_function_exists("image_" . $toolkit . "_resize")) {
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}
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elseif (!drupal_function_exists("image_gd_check_settings") ||
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!image_gd_check_settings()) {
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$toolkit = FALSE;
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}
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}
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return $toolkit;
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}
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/**
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* Invokes the given method using the currently selected toolkit.
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*
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* @param $method
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* A string containing the method to invoke.
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* @param $params
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* An optional array of parameters to pass to the toolkit method.
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* @return
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* Mixed values (typically Boolean indicating successful operation).
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*/
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function image_toolkit_invoke($method, $params = array()) {
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if ($toolkit = image_get_toolkit()) {
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$function = 'image_' . $toolkit . '_' . $method;
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if (drupal_function_exists($function)) {
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return call_user_func_array($function, $params);
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}
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else {
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watchdog('php', 'The selected image handling toolkit %toolkit can not correctly process %function.', array('%toolkit' => $toolkit, '%function' => $function), WATCHDOG_ERROR);
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return FALSE;
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}
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}
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}
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/**
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* Get details about an image.
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*
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* Drupal only supports GIF, JPG and PNG file formats.
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*
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* @return
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* FALSE, if the file could not be found or is not an image. Otherwise, a
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* keyed array containing information about the image:
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* 'width' - Width in pixels.
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* 'height' - Height in pixels.
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* 'extension' - Commonly used file extension for the image.
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* 'mime_type' - MIME type ('image/jpeg', 'image/gif', 'image/png').
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* 'file_size' - File size in bytes.
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*/
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function image_get_info($file) {
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if (!is_file($file)) {
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return FALSE;
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}
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$details = FALSE;
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$data = @getimagesize($file);
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$file_size = @filesize($file);
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if (isset($data) && is_array($data)) {
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$extensions = array('1' => 'gif', '2' => 'jpg', '3' => 'png');
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$extension = array_key_exists($data[2], $extensions) ? $extensions[$data[2]] : '';
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$details = array('width' => $data[0],
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'height' => $data[1],
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'extension' => $extension,
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'file_size' => $file_size,
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'mime_type' => $data['mime']);
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}
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return $details;
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}
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/**
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* Scales an image to the exact width and height given. Achieves the
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* target aspect ratio by cropping the original image equally on both
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* sides, or equally on the top and bottom. This function is, for
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* example, useful to create uniform sized avatars from larger images.
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*
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* The resulting image always has the exact target dimensions.
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*
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* @param $source
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* The file path of the source image.
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* @param $destination
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* The file path of the destination image.
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* @param $width
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* The target width, in pixels.
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* @param $height
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* The target height, in pixels.
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* @return
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* TRUE or FALSE, based on success.
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*/
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function image_scale_and_crop($source, $destination, $width, $height) {
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$info = image_get_info($source);
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$scale = max($width / $info['width'], $height / $info['height']);
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$x = round(($info['width'] * $scale - $width) / 2);
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$y = round(($info['height'] * $scale - $height) / 2);
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if (image_toolkit_invoke('resize', array($source, $destination, $info['width'] * $scale, $info['height'] * $scale))) {
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return image_toolkit_invoke('crop', array($destination, $destination, $x, $y, $width, $height));
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}
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return FALSE;
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}
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/**
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* Scales an image to the given width and height while maintaining aspect
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* ratio.
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*
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* The resulting image can be smaller for one or both target dimensions.
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*
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* @param $source
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* The file path of the source image.
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* @param $destination
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* The file path of the destination image.
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* @param $width
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* The target width, in pixels.
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* @param $height
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* The target height, in pixels.
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* @return
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* TRUE or FALSE, based on success.
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*/
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function image_scale($source, $destination, $width, $height) {
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$info = image_get_info($source);
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// Don't scale up.
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if ($width >= $info['width'] && $height >= $info['height']) {
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return FALSE;
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}
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$aspect = $info['height'] / $info['width'];
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if ($aspect < $height / $width) {
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$width = (int)min($width, $info['width']);
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$height = (int)round($width * $aspect);
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}
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else {
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$height = (int)min($height, $info['height']);
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$width = (int)round($height / $aspect);
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}
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return image_toolkit_invoke('resize', array($source, $destination, $width, $height));
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}
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/**
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* Resize an image to the given dimensions (ignoring aspect ratio).
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*
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* @param $source
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* The file path of the source image.
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* @param $destination
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* The file path of the destination image.
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* @param $width
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* The target width, in pixels.
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* @param $height
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* The target height, in pixels.
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* @return
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* TRUE or FALSE, based on success.
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*/
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function image_resize($source, $destination, $width, $height) {
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return image_toolkit_invoke('resize', array($source, $destination, $width, $height));
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}
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/**
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* Rotate an image by the given number of degrees.
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*
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* @param $source
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* The file path of the source image.
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* @param $destination
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* The file path of the destination image.
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* @param $degrees
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* The number of (clockwise) degrees to rotate the image.
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* @param $background
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* An hexidecimal integer specifying the background color to use for the
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* uncovered area of the image after the rotation. E.g. 0x000000 for black,
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* 0xff00ff for magenta, and 0xffffff for white.
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* @return
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* TRUE or FALSE, based on success.
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*/
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function image_rotate($source, $destination, $degrees, $background = 0x000000) {
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return image_toolkit_invoke('rotate', array($source, $destination, $degrees, $background));
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}
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/**
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* Crop an image to the rectangle specified by the given rectangle.
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*
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* @param $source
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* The file path of the source image.
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* @param $destination
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* The file path of the destination image.
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* @param $x
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* The top left co-ordinate, in pixels, of the crop area (x axis value).
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* @param $y
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* The top left co-ordinate, in pixels, of the crop area (y axis value).
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* @param $width
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* The target width, in pixels.
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* @param $height
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* The target height, in pixels.
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* @return
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* TRUE or FALSE, based on success.
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*/
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function image_crop($source, $destination, $x, $y, $width, $height) {
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return image_toolkit_invoke('crop', array($source, $destination, $x, $y, $width, $height));
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}
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/**
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* @} End of "defgroup image".
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*/
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