server/lib/image.php

294 lines
8.7 KiB
PHP

<?php
/**
* ownCloud
*
* @author Thomas Tanghus
* @copyright 2011 Thomas Tanghus <thomas@tanghus.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
* License as published by the Free Software Foundation; either
* version 3 of the License, or any later version.
*
* This library 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 AFFERO GENERAL PUBLIC LICENSE for more details.
*
* You should have received a copy of the GNU Affero General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
*/
/**
* Class for image manipulation
* Ideas: imagerotate, chunk_split(base64_encode())
*
*/
class OC_Image {
static private $resource = false; // tmp resource.
static private $destroy = false; // if the resource is created withing the object.
/**
* @brief Constructor.
* @param $imageref The path to a local file, a base64 encoded string or a resource created by an imagecreate* function.
* If a resource is passed it is the job of the caller to destroy it using imagedestroy($var)
* @returns bool False on error
*/
function __construct($imageref = null) {
OC_Log::write('core','OC_Image::__construct, start', OC_Log::DEBUG);
if(!function_exists('imagecreatefromjpeg')) { // FIXME: Find a better way to check for GD
OC_Log::write('core','OC_Image::__construct, GD module not installed', OC_Log::ERROR);
return false;
}
if(!is_null($imageref)) {
self::load($imageref);
}
}
/**
* @brief Destructor.
*/
function __destruct() {
if(self::$resource && self::$destroy) {
imagedestroy(self::$resource); // Why does this issue a warning.
}
}
/**
* @brief Prints the image.
*/
public function show() {
header('Content-Type: image/png');
imagepng(self::$resource);
}
/**
* @brief Prints the image when called as $image().
*/
public function __invoke() {
self::show();
}
/**
* @returns Returns the image resource in any.
*/
public function imageResource() {
return self::$resource;
}
/**
* @returns Returns a base64 encoded string suitable for embedding in a VCard.
*/
function __toString() {
ob_start();
$res = imagepng(self::$resource);
if (!$res) {
OC_Log::write('core','OC_Image::_string. Error writing image',OC_Log::ERROR);
}
return chunk_split(base64_encode(ob_get_clean()));
}
/**
* @brief Loads an image from a local file, a base64 encoded string or a resource created by an imagecreate* function.
* @param $imageref The path to a local file, a base64 encoded string or a resource created by an imagecreate* function.
* If a resource is passed it is the job of the caller to destroy it using imagedestroy($var)
* @returns An image resource or false on error
*/
static public function load($imageref) {
if(self::loadFromFile($imageref) !== false) {
return self::$resource;
} elseif(self::loadFromBase64($imageref) !== false) {
return self::$resource;
} elseif(self::loadFromData($imageref) !== false) {
return self::$resource;
} elseif(self::loadFromResource($imageref) !== false) {
return self::$resource;
} else {
OC_Log::write('core','OC_Image::load, couldn\'t load anything. Giving up!', OC_Log::DEBUG);
return false;
}
}
/**
* @brief Loads an image from a local file.
* @param $imageref The path to a local file.
* @returns An image resource or false on error
*/
static public function loadFromFile($imagepath=false) {
if(!is_string($imagepath)) {
return false;
}
if(!is_file($imagepath) || !file_exists($imagepath) || !is_readable($imagepath)) {
OC_Log::write('core','OC_Image::loadFromFile, couldn\'t load'.$imagepath, OC_Log::DEBUG);
return false;
}
self::$resource = imagecreatefromstring(file_get_contents($imagepath));
self::$destroy = true;
return self::$resource;
}
/**
* @brief Loads an image from a string of data.
* @param $str A string of image data as read from a file.
* @returns An image resource or false on error
*/
static public function loadFromData($str) {
if(is_resource($str)) {
return false;
}
self::$resource = imagecreatefromstring($str);
if(!self::$resource) {
OC_Log::write('core','OC_Image::loadFromData, couldn\'t load', OC_Log::DEBUG);
return false;
}
self::$destroy = true;
return self::$resource;
}
/**
* @brief Loads an image from a base64 encoded string.
* @param $str A string base64 encoded string of image data.
* @returns An image resource or false on error
*/
static public function loadFromBase64($str) {
if(!is_string($str)) {
return false;
}
$data = base64_decode($str);
if($data) { // try to load from string data
self::$resource = imagecreatefromstring($data);
if(!self::$resource) {
OC_Log::write('core','OC_Image::loadFromBase64, couldn\'t load', OC_Log::DEBUG);
return false;
}
self::$destroy = true;
return self::$resource;
} else {
return false;
}
}
/**
* @brief Checks if image resource is valid and assigns it to self::$resource.
* @param $res An image resource.
* @returns An image resource or false on error
*/
static public function loadFromResource($res) {
if(!is_resource($res)) {
return false;
}
self::$resource = $res;
}
/**
* @brief Resizes the image preserving ratio.
* @param $maxsize The maximum size of either the width or height.
* @returns bool
*/
public function resize($maxsize) {
if(!self::$resource) {
OC_Log::write('core','OC_Image::resize, No image loaded', OC_Log::ERROR);
return false;
}
$width_orig=imageSX(self::$resource);
$height_orig=imageSY(self::$resource);
$ratio_orig = $width_orig/$height_orig;
if ($ratio_orig > 1) {
$new_height = round($maxsize/$ratio_orig);
$new_width = $maxsize;
} else {
$new_width = round($maxsize*$ratio_orig);
$new_height = $maxsize;
}
$process = imagecreatetruecolor(round($new_width), round($new_height));
if ($process == false) {
OC_Log::write('core','OC_Image::resize. Error creating true color image',OC_Log::ERROR);
imagedestroy($process);
return false;
}
imagecopyresampled($process, self::$resource, 0, 0, 0, 0, $new_width, $new_height, $width_orig, $height_orig);
if ($process == false) {
OC_Log::write('core','OC_Image::resize. Error resampling process image '.$new_width.'x'.$new_height,OC_Log::ERROR);
imagedestroy($process);
return false;
}
self::$resource = $process;
return true;
}
/**
* @brief Crops the image to the middle square. If the image is already square it just returns.
* @returns bool for success or failure
*/
public function centerCrop() {
if(!self::$resource) {
OC_Log::write('core','OC_Image::centerCrop, No image loaded', OC_Log::ERROR);
return false;
}
$width_orig=imageSX(self::$resource);
$height_orig=imageSY(self::$resource);
if($width_orig === $height_orig) {
return true;
}
$ratio_orig = $width_orig/$height_orig;
$width = $height = min($width_orig, $height_orig);
if ($ratio_orig > 1) {
$x = ($width_orig/2) - ($width/2);
$y = 0;
} else {
$y = ($height_orig/2) - ($height/2);
$x = 0;
}
$process = imagecreatetruecolor($width, $height);
if ($process == false) {
OC_Log::write('core','OC_Image::centerCrop. Error creating true color image',OC_Log::ERROR);
imagedestroy($process);
return false;
}
imagecopyresampled($process, self::$resource, 0, 0, $x, $y, $width, $height, $width, $height);
if ($process == false) {
OC_Log::write('core','OC_Image::centerCrop. Error resampling process image '.$width.'x'.$height,OC_Log::ERROR);
imagedestroy($process);
return false;
}
self::$resource = $process;
return true;
}
/**
* @brief Crops the image from point $x$y with dimension $wx$h.
* @param $x Horizontal position
* @param $y Vertical position
* @param $w Width
* @param $h Hight
* @returns bool for success or failure
*/
public function crop($x, $y, $w, $h) {
if(!self::$resource) {
OC_Log::write('core','OC_Image::crop, No image loaded', OC_Log::ERROR);
return false;
}
$width_orig=imageSX(self::$resource);
$height_orig=imageSY(self::$resource);
//OC_Log::write('core','OC_Image::crop. Original size: '.$width_orig.'x'.$height_orig, OC_Log::DEBUG);
$process = imagecreatetruecolor($w, $h);
if ($process == false) {
OC_Log::write('core','OC_Image::crop. Error creating true color image',OC_Log::ERROR);
imagedestroy($process);
return false;
}
imagecopyresampled($process, self::$resource, 0, 0, $x, $y, $w, $h, $w, $h);
if ($process == false) {
OC_Log::write('core','OC_Image::crop. Error resampling process image '.$w.'x'.$h,OC_Log::ERROR);
imagedestroy($process);
return false;
}
self::$resource = $process;
return true;
}
}