image.gd.inc
GD2 toolkit for image manipulation within Drupal.
File
drupal-6.x/includes/image.gd.incView source
- <?php
-
- /**
- * @file
- * GD2 toolkit for image manipulation within Drupal.
- */
-
- /**
- * @ingroup image
- * @{
- */
-
- /**
- * Retrieve information about the toolkit.
- */
- function image_gd_info() {
- return array('name' => 'gd', 'title' => t('GD2 image manipulation toolkit'));
- }
-
- /**
- * Retrieve settings for the GD2 toolkit.
- */
- function image_gd_settings() {
- if (image_gd_check_settings()) {
- $form = array();
- $form['status'] = array(
- '#value' => t('The GD toolkit is installed and working properly.')
- );
-
- $form['image_jpeg_quality'] = array(
- '#type' => 'textfield',
- '#title' => t('JPEG quality'),
- '#description' => t('Define the image quality for JPEG manipulations. Ranges from 0 to 100. Higher values mean better image quality but bigger files.'),
- '#size' => 10,
- '#maxlength' => 3,
- '#default_value' => variable_get('image_jpeg_quality', 75),
- '#field_suffix' => t('%'),
- );
- $form['#element_validate'] = array('image_gd_settings_validate');
-
- return $form;
- }
- else {
- form_set_error('image_toolkit', t('The GD image toolkit requires that the GD module for PHP be installed and configured properly. For more information see <a href="@url">PHP\'s image documentation</a>.', array('@url' => 'http://php.net/image')));
- return FALSE;
- }
- }
-
- /**
- * Validate the submitted GD settings.
- */
- function image_gd_settings_validate($form, &$form_state) {
- // Validate image quality range.
- $value = $form_state['values']['image_jpeg_quality'];
- if (!is_numeric($value) || $value < 0 || $value > 100) {
- form_set_error('image_jpeg_quality', t('JPEG quality must be a number between 0 and 100.'));
- }
- }
-
- /**
- * Verify GD2 settings (that the right version is actually installed).
- *
- * @return
- * A boolean indicating if the GD toolkit is avaiable on this machine.
- */
- function image_gd_check_settings() {
- if ($check = get_extension_funcs('gd')) {
- if (in_array('imagegd2', $check)) {
- // GD2 support is available.
- return TRUE;
- }
- }
- return FALSE;
- }
-
- /**
- * Scale an image to the specified size using GD.
- */
- function image_gd_resize($source, $destination, $width, $height) {
- if (!file_exists($source)) {
- return FALSE;
- }
-
- $info = image_get_info($source);
- if (!$info) {
- return FALSE;
- }
-
- $im = image_gd_open($source, $info['extension']);
- if (!$im) {
- return FALSE;
- }
-
- $res = imagecreatetruecolor($width, $height);
- if ($info['extension'] == 'png') {
- $transparency = imagecolorallocatealpha($res, 0, 0, 0, 127);
- imagealphablending($res, FALSE);
- imagefilledrectangle($res, 0, 0, $width, $height, $transparency);
- imagealphablending($res, TRUE);
- imagesavealpha($res, TRUE);
- }
- elseif ($info['extension'] == 'gif') {
- // If we have a specific transparent color.
- $transparency_index = imagecolortransparent($im);
- if ($transparency_index >= 0) {
- // Get the original image's transparent color's RGB values.
- $transparent_color = imagecolorsforindex($im, $transparency_index);
- // Allocate the same color in the new image resource.
- $transparency_index = imagecolorallocate($res, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
- // Completely fill the background of the new image with allocated color.
- imagefill($res, 0, 0, $transparency_index);
- // Set the background color for new image to transparent.
- imagecolortransparent($res, $transparency_index);
- // Find number of colors in the images palette.
- $number_colors = imagecolorstotal($im);
- // Convert from true color to palette to fix transparency issues.
- imagetruecolortopalette($res, TRUE, $number_colors);
- }
- }
- imagecopyresampled($res, $im, 0, 0, 0, 0, $width, $height, $info['width'], $info['height']);
- $result = image_gd_close($res, $destination, $info['extension']);
-
- imagedestroy($res);
- imagedestroy($im);
-
- return $result;
- }
-
- /**
- * Rotate an image the given number of degrees.
- */
- function image_gd_rotate($source, $destination, $degrees, $background = 0x000000) {
- if (!function_exists('imageRotate')) {
- return FALSE;
- }
-
- $info = image_get_info($source);
- if (!$info) {
- return FALSE;
- }
-
- $im = image_gd_open($source, $info['extension']);
- if (!$im) {
- return FALSE;
- }
-
- $res = imageRotate($im, $degrees, $background);
- $result = image_gd_close($res, $destination, $info['extension']);
-
- return $result;
- }
-
- /**
- * Crop an image using the GD toolkit.
- */
- function image_gd_crop($source, $destination, $x, $y, $width, $height) {
- $info = image_get_info($source);
- if (!$info) {
- return FALSE;
- }
-
- $im = image_gd_open($source, $info['extension']);
- $res = imageCreateTrueColor($width, $height);
- imageCopy($res, $im, 0, 0, $x, $y, $width, $height);
- $result = image_gd_close($res, $destination, $info['extension']);
-
- imageDestroy($res);
- imageDestroy($im);
-
- return $result;
- }
-
- /**
- * GD helper function to create an image resource from a file.
- *
- * @param $file
- * A string file path where the iamge should be saved.
- * @param $extension
- * A string containing one of the following extensions: gif, jpg, jpeg, png.
- * @return
- * An image resource, or FALSE on error.
- */
- function image_gd_open($file, $extension) {
- $extension = str_replace('jpg', 'jpeg', $extension);
- $open_func = 'imageCreateFrom'. $extension;
- if (!function_exists($open_func)) {
- return FALSE;
- }
- return $open_func($file);
- }
-
- /**
- * GD helper to write an image resource to a destination file.
- *
- * @param $res
- * An image resource created with image_gd_open().
- * @param $destination
- * A string file path where the iamge should be saved.
- * @param $extension
- * A string containing one of the following extensions: gif, jpg, jpeg, png.
- * @return
- * Boolean indicating success.
- */
- function image_gd_close($res, $destination, $extension) {
- $extension = str_replace('jpg', 'jpeg', $extension);
- $close_func = 'image'. $extension;
- if (!function_exists($close_func)) {
- return FALSE;
- }
- if ($extension == 'jpeg') {
- return $close_func($res, $destination, variable_get('image_jpeg_quality', 75));
- }
- else {
- return $close_func($res, $destination);
- }
- }
-
- /**
- * @} End of "ingroup image".
- */