Permalink
Find file
Fetching contributors…
Cannot retrieve contributors at this time
272 lines (246 sloc) 8.35 KB
<?php
/**
* @file
* API for manipulating images.
*/
/**
* @defgroup image Image toolkits
* @{
* Drupal's image toolkits provide an abstraction layer for common image file
* manipulations like scaling, cropping, and rotating. The abstraction frees
* module authors from the need to support multiple image libraries, and it
* allows site administrators to choose the library that's best for them.
*
* PHP includes the GD library by default so a GD toolkit is installed with
* Drupal. Other toolkits like ImageMagic are available from contrib modules.
* GD works well for small images, but using it with larger files may cause PHP
* to run out of memory. In contrast the ImageMagick library does not suffer
* from this problem, but it requires the ISP to have installed additional
* software.
*
* Image toolkits are installed by copying the image.ToolkitName.inc file into
* Drupal's includes directory. The toolkit must then be enabled using the
* admin/settings/image-toolkit form.
*
* Only one toolkit maybe selected at a time. If a module author wishes to call
* a specific toolkit they can check that it is installed by calling
* image_get_available_toolkits(), and then calling its functions directly.
*/
/**
* Return a list of available toolkits.
*
* @return
* An array of toolkit name => descriptive title.
*/
function image_get_available_toolkits() {
$toolkits = file_scan_directory('includes', 'image\..*\.inc$');
$output = array();
foreach ($toolkits as $file => $toolkit) {
include_once "./$file";
$function = str_replace('.', '_', $toolkit->name) .'_info';
if (function_exists($function)) {
$info = $function();
$output[$info['name']] = $info['title'];
}
}
return $output;
}
/**
* Retrieve the name of the currently used toolkit.
*
* @return
* String containing the name of the selected toolkit, or FALSE on error.
*/
function image_get_toolkit() {
static $toolkit;
if (!$toolkit) {
$toolkit = variable_get('image_toolkit', 'gd');
$toolkit_file = './includes/image.'. $toolkit .'.inc';
if (isset($toolkit) && file_exists($toolkit_file)) {
include_once $toolkit_file;
}
elseif (!image_gd_check_settings()) {
$toolkit = FALSE;
}
}
return $toolkit;
}
/**
* Invokes the given method using the currently selected toolkit.
*
* @param $method
* A string containing the method to invoke.
* @param $params
* An optional array of parameters to pass to the toolkit method.
* @return
* Mixed values (typically Boolean indicating successful operation).
*/
function image_toolkit_invoke($method, $params = array()) {
if ($toolkit = image_get_toolkit()) {
$function = 'image_'. $toolkit .'_'. $method;
if (function_exists($function)) {
return call_user_func_array($function, $params);
}
else {
watchdog('php', 'The selected image handling toolkit %toolkit can not correctly process %function.', array('%toolkit' => $toolkit, '%function' => $function), WATCHDOG_ERROR);
return FALSE;
}
}
}
/**
* Get details about an image.
*
* Drupal only supports GIF, JPG and PNG file formats.
*
* @return
* FALSE, if the file could not be found or is not an image. Otherwise, a
* keyed array containing information about the image:
* 'width' - Width in pixels.
* 'height' - Height in pixels.
* 'extension' - Commonly used file extension for the image.
* 'mime_type' - MIME type ('image/jpeg', 'image/gif', 'image/png').
* 'file_size' - File size in bytes.
*/
function image_get_info($file) {
// Proceed no further if this file doesn't exist. Some web servers (IIS) may
// not pass is_file() for newly uploaded files, so we need two checks here.
if (!is_file($file) && !is_uploaded_file($file)) {
return FALSE;
}
$details = FALSE;
$data = @getimagesize($file);
$file_size = @filesize($file);
if (isset($data) && is_array($data)) {
$extensions = array('1' => 'gif', '2' => 'jpg', '3' => 'png');
$extension = array_key_exists($data[2], $extensions) ? $extensions[$data[2]] : '';
$details = array('width' => $data[0],
'height' => $data[1],
'extension' => $extension,
'file_size' => $file_size,
'mime_type' => $data['mime']);
}
return $details;
}
/**
* Scales an image to the exact width and height given. Achieves the
* target aspect ratio by cropping the original image equally on both
* sides, or equally on the top and bottom. This function is, for
* example, useful to create uniform sized avatars from larger images.
*
* The resulting image always has the exact target dimensions.
*
* @param $source
* The file path of the source image.
* @param $destination
* The file path of the destination image.
* @param $width
* The target width, in pixels.
* @param $height
* The target height, in pixels.
* @return
* TRUE or FALSE, based on success.
*/
function image_scale_and_crop($source, $destination, $width, $height) {
$info = image_get_info($source);
$scale = max($width / $info['width'], $height / $info['height']);
$x = round(($info['width'] * $scale - $width) / 2);
$y = round(($info['height'] * $scale - $height) / 2);
if (image_toolkit_invoke('resize', array($source, $destination, $info['width'] * $scale, $info['height'] * $scale))) {
return image_toolkit_invoke('crop', array($destination, $destination, $x, $y, $width, $height));
}
return FALSE;
}
/**
* Scales an image to the given width and height while maintaining aspect
* ratio.
*
* The resulting image can be smaller for one or both target dimensions.
*
* @param $source
* The file path of the source image.
* @param $destination
* The file path of the destination image.
* @param $width
* The target width, in pixels.
* @param $height
* The target height, in pixels.
* @return
* TRUE or FALSE, based on success.
*/
function image_scale($source, $destination, $width, $height) {
$info = image_get_info($source);
// Don't scale up.
if ($width >= $info['width'] && $height >= $info['height']) {
return FALSE;
}
$aspect = $info['height'] / $info['width'];
if ($aspect < $height / $width) {
$width = (int)min($width, $info['width']);
$height = (int)round($width * $aspect);
}
else {
$height = (int)min($height, $info['height']);
$width = (int)round($height / $aspect);
}
return image_toolkit_invoke('resize', array($source, $destination, $width, $height));
}
/**
* Resize an image to the given dimensions (ignoring aspect ratio).
*
* @param $source
* The file path of the source image.
* @param $destination
* The file path of the destination image.
* @param $width
* The target width, in pixels.
* @param $height
* The target height, in pixels.
* @return
* TRUE or FALSE, based on success.
*/
function image_resize($source, $destination, $width, $height) {
return image_toolkit_invoke('resize', array($source, $destination, $width, $height));
}
/**
* Rotate an image by the given number of degrees.
*
* @param $source
* The file path of the source image.
* @param $destination
* The file path of the destination image.
* @param $degrees
* The number of (clockwise) degrees to rotate the image.
* @param $background
* An hexidecimal integer specifying the background color to use for the
* uncovered area of the image after the rotation. E.g. 0x000000 for black,
* 0xff00ff for magenta, and 0xffffff for white.
* @return
* TRUE or FALSE, based on success.
*/
function image_rotate($source, $destination, $degrees, $background = 0x000000) {
return image_toolkit_invoke('rotate', array($source, $destination, $degrees, $background));
}
/**
* Crop an image to the rectangle specified by the given rectangle.
*
* @param $source
* The file path of the source image.
* @param $destination
* The file path of the destination image.
* @param $x
* The top left co-ordinate, in pixels, of the crop area (x axis value).
* @param $y
* The top left co-ordinate, in pixels, of the crop area (y axis value).
* @param $width
* The target width, in pixels.
* @param $height
* The target height, in pixels.
* @return
* TRUE or FALSE, based on success.
*/
function image_crop($source, $destination, $x, $y, $width, $height) {
return image_toolkit_invoke('crop', array($source, $destination, $x, $y, $width, $height));
}
/**
* @} End of "defgroup image".
*/