image.inc
API for manipulating images.
File
drupal-6.x/includes/image.incView source
- <?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".
- */