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khosb/includes/kohana/modules/image/classes/Kohana/Image/GD.php
2012-12-21 12:59:09 +11:00

666 lines
16 KiB
PHP

<?php defined('SYSPATH') OR die('No direct script access.');
/**
* Support for image manipulation using [GD](http://php.net/GD).
*
* @package Kohana/Image
* @category Drivers
* @author Kohana Team
* @copyright (c) 2008-2009 Kohana Team
* @license http://kohanaphp.com/license.html
*/
class Kohana_Image_GD extends Image {
// Is GD bundled or separate?
protected static $_bundled;
/**
* Checks if GD is enabled and bundled. Bundled GD is required for some
* methods to work. Exceptions will be thrown from those methods when GD is
* not bundled.
*
* @return boolean
*/
public static function check()
{
if ( ! function_exists('gd_info'))
{
throw new Kohana_Exception('GD is either not installed or not enabled, check your configuration');
}
if (defined('GD_BUNDLED'))
{
// Get the version via a constant, available in PHP 5.
Image_GD::$_bundled = GD_BUNDLED;
}
else
{
// Get the version information
$info = gd_info();
// Extract the bundled status
Image_GD::$_bundled = (bool) preg_match('/\bbundled\b/i', $info['GD Version']);
}
if (defined('GD_VERSION'))
{
// Get the version via a constant, available in PHP 5.2.4+
$version = GD_VERSION;
}
else
{
// Get the version information
$info = gd_info();
// Extract the version number
preg_match('/\d+\.\d+(?:\.\d+)?/', $info['GD Version'], $matches);
// Get the major version
$version = $matches[0];
}
if ( ! version_compare($version, '2.0.1', '>='))
{
throw new Kohana_Exception('Image_GD requires GD version :required or greater, you have :version',
array('required' => '2.0.1', ':version' => $version));
}
return Image_GD::$_checked = TRUE;
}
// Temporary image resource
protected $_image;
// Function name to open Image
protected $_create_function;
/**
* Runs [Image_GD::check] and loads the image.
*
* @param string $file image file path
* @return void
* @throws Kohana_Exception
*/
public function __construct($file)
{
if ( ! Image_GD::$_checked)
{
// Run the install check
Image_GD::check();
}
parent::__construct($file);
// Set the image creation function name
switch ($this->type)
{
case IMAGETYPE_JPEG:
$create = 'imagecreatefromjpeg';
break;
case IMAGETYPE_GIF:
$create = 'imagecreatefromgif';
break;
case IMAGETYPE_PNG:
$create = 'imagecreatefrompng';
break;
}
if ( ! isset($create) OR ! function_exists($create))
{
throw new Kohana_Exception('Installed GD does not support :type images',
array(':type' => image_type_to_extension($this->type, FALSE)));
}
// Save function for future use
$this->_create_function = $create;
// Save filename for lazy loading
$this->_image = $this->file;
}
/**
* Destroys the loaded image to free up resources.
*
* @return void
*/
public function __destruct()
{
if (is_resource($this->_image))
{
// Free all resources
imagedestroy($this->_image);
}
}
/**
* Loads an image into GD.
*
* @return void
*/
protected function _load_image()
{
if ( ! is_resource($this->_image))
{
// Gets create function
$create = $this->_create_function;
// Open the temporary image
$this->_image = $create($this->file);
// Preserve transparency when saving
imagesavealpha($this->_image, TRUE);
}
}
/**
* Execute a resize.
*
* @param integer $width new width
* @param integer $height new height
* @return void
*/
protected function _do_resize($width, $height)
{
// Presize width and height
$pre_width = $this->width;
$pre_height = $this->height;
// Loads image if not yet loaded
$this->_load_image();
// Test if we can do a resize without resampling to speed up the final resize
if ($width > ($this->width / 2) AND $height > ($this->height / 2))
{
// The maximum reduction is 10% greater than the final size
$reduction_width = round($width * 1.1);
$reduction_height = round($height * 1.1);
while ($pre_width / 2 > $reduction_width AND $pre_height / 2 > $reduction_height)
{
// Reduce the size using an O(2n) algorithm, until it reaches the maximum reduction
$pre_width /= 2;
$pre_height /= 2;
}
// Create the temporary image to copy to
$image = $this->_create($pre_width, $pre_height);
if (imagecopyresized($image, $this->_image, 0, 0, 0, 0, $pre_width, $pre_height, $this->width, $this->height))
{
// Swap the new image for the old one
imagedestroy($this->_image);
$this->_image = $image;
}
}
// Create the temporary image to copy to
$image = $this->_create($width, $height);
// Execute the resize
if (imagecopyresampled($image, $this->_image, 0, 0, 0, 0, $width, $height, $pre_width, $pre_height))
{
// Swap the new image for the old one
imagedestroy($this->_image);
$this->_image = $image;
// Reset the width and height
$this->width = imagesx($image);
$this->height = imagesy($image);
}
}
/**
* Execute a crop.
*
* @param integer $width new width
* @param integer $height new height
* @param integer $offset_x offset from the left
* @param integer $offset_y offset from the top
* @return void
*/
protected function _do_crop($width, $height, $offset_x, $offset_y)
{
// Create the temporary image to copy to
$image = $this->_create($width, $height);
// Loads image if not yet loaded
$this->_load_image();
// Execute the crop
if (imagecopyresampled($image, $this->_image, 0, 0, $offset_x, $offset_y, $width, $height, $width, $height))
{
// Swap the new image for the old one
imagedestroy($this->_image);
$this->_image = $image;
// Reset the width and height
$this->width = imagesx($image);
$this->height = imagesy($image);
}
}
/**
* Execute a rotation.
*
* @param integer $degrees degrees to rotate
* @return void
*/
protected function _do_rotate($degrees)
{
if ( ! Image_GD::$_bundled)
{
throw new Kohana_Exception('This method requires :function, which is only available in the bundled version of GD',
array(':function' => 'imagerotate'));
}
// Loads image if not yet loaded
$this->_load_image();
// Transparent black will be used as the background for the uncovered region
$transparent = imagecolorallocatealpha($this->_image, 0, 0, 0, 127);
// Rotate, setting the transparent color
$image = imagerotate($this->_image, 360 - $degrees, $transparent, 1);
// Save the alpha of the rotated image
imagesavealpha($image, TRUE);
// Get the width and height of the rotated image
$width = imagesx($image);
$height = imagesy($image);
if (imagecopymerge($this->_image, $image, 0, 0, 0, 0, $width, $height, 100))
{
// Swap the new image for the old one
imagedestroy($this->_image);
$this->_image = $image;
// Reset the width and height
$this->width = $width;
$this->height = $height;
}
}
/**
* Execute a flip.
*
* @param integer $direction direction to flip
* @return void
*/
protected function _do_flip($direction)
{
// Create the flipped image
$flipped = $this->_create($this->width, $this->height);
// Loads image if not yet loaded
$this->_load_image();
if ($direction === Image::HORIZONTAL)
{
for ($x = 0; $x < $this->width; $x++)
{
// Flip each row from top to bottom
imagecopy($flipped, $this->_image, $x, 0, $this->width - $x - 1, 0, 1, $this->height);
}
}
else
{
for ($y = 0; $y < $this->height; $y++)
{
// Flip each column from left to right
imagecopy($flipped, $this->_image, 0, $y, 0, $this->height - $y - 1, $this->width, 1);
}
}
// Swap the new image for the old one
imagedestroy($this->_image);
$this->_image = $flipped;
// Reset the width and height
$this->width = imagesx($flipped);
$this->height = imagesy($flipped);
}
/**
* Execute a sharpen.
*
* @param integer $amount amount to sharpen
* @return void
*/
protected function _do_sharpen($amount)
{
if ( ! Image_GD::$_bundled)
{
throw new Kohana_Exception('This method requires :function, which is only available in the bundled version of GD',
array(':function' => 'imageconvolution'));
}
// Loads image if not yet loaded
$this->_load_image();
// Amount should be in the range of 18-10
$amount = round(abs(-18 + ($amount * 0.08)), 2);
// Gaussian blur matrix
$matrix = array
(
array(-1, -1, -1),
array(-1, $amount, -1),
array(-1, -1, -1),
);
// Perform the sharpen
if (imageconvolution($this->_image, $matrix, $amount - 8, 0))
{
// Reset the width and height
$this->width = imagesx($this->_image);
$this->height = imagesy($this->_image);
}
}
/**
* Execute a reflection.
*
* @param integer $height reflection height
* @param integer $opacity reflection opacity
* @param boolean $fade_in TRUE to fade out, FALSE to fade in
* @return void
*/
protected function _do_reflection($height, $opacity, $fade_in)
{
if ( ! Image_GD::$_bundled)
{
throw new Kohana_Exception('This method requires :function, which is only available in the bundled version of GD',
array(':function' => 'imagefilter'));
}
// Loads image if not yet loaded
$this->_load_image();
// Convert an opacity range of 0-100 to 127-0
$opacity = round(abs(($opacity * 127 / 100) - 127));
if ($opacity < 127)
{
// Calculate the opacity stepping
$stepping = (127 - $opacity) / $height;
}
else
{
// Avoid a "divide by zero" error
$stepping = 127 / $height;
}
// Create the reflection image
$reflection = $this->_create($this->width, $this->height + $height);
// Copy the image to the reflection
imagecopy($reflection, $this->_image, 0, 0, 0, 0, $this->width, $this->height);
for ($offset = 0; $height >= $offset; $offset++)
{
// Read the next line down
$src_y = $this->height - $offset - 1;
// Place the line at the bottom of the reflection
$dst_y = $this->height + $offset;
if ($fade_in === TRUE)
{
// Start with the most transparent line first
$dst_opacity = round($opacity + ($stepping * ($height - $offset)));
}
else
{
// Start with the most opaque line first
$dst_opacity = round($opacity + ($stepping * $offset));
}
// Create a single line of the image
$line = $this->_create($this->width, 1);
// Copy a single line from the current image into the line
imagecopy($line, $this->_image, 0, 0, 0, $src_y, $this->width, 1);
// Colorize the line to add the correct alpha level
imagefilter($line, IMG_FILTER_COLORIZE, 0, 0, 0, $dst_opacity);
// Copy a the line into the reflection
imagecopy($reflection, $line, 0, $dst_y, 0, 0, $this->width, 1);
}
// Swap the new image for the old one
imagedestroy($this->_image);
$this->_image = $reflection;
// Reset the width and height
$this->width = imagesx($reflection);
$this->height = imagesy($reflection);
}
/**
* Execute a watermarking.
*
* @param Image $image watermarking Image
* @param integer $offset_x offset from the left
* @param integer $offset_y offset from the top
* @param integer $opacity opacity of watermark
* @return void
*/
protected function _do_watermark(Image $watermark, $offset_x, $offset_y, $opacity)
{
if ( ! Image_GD::$_bundled)
{
throw new Kohana_Exception('This method requires :function, which is only available in the bundled version of GD',
array(':function' => 'imagelayereffect'));
}
// Loads image if not yet loaded
$this->_load_image();
// Create the watermark image resource
$overlay = imagecreatefromstring($watermark->render());
imagesavealpha($overlay, TRUE);
// Get the width and height of the watermark
$width = imagesx($overlay);
$height = imagesy($overlay);
if ($opacity < 100)
{
// Convert an opacity range of 0-100 to 127-0
$opacity = round(abs(($opacity * 127 / 100) - 127));
// Allocate transparent gray
$color = imagecolorallocatealpha($overlay, 127, 127, 127, $opacity);
// The transparent image will overlay the watermark
imagelayereffect($overlay, IMG_EFFECT_OVERLAY);
// Fill the background with the transparent color
imagefilledrectangle($overlay, 0, 0, $width, $height, $color);
}
// Alpha blending must be enabled on the background!
imagealphablending($this->_image, TRUE);
if (imagecopy($this->_image, $overlay, $offset_x, $offset_y, 0, 0, $width, $height))
{
// Destroy the overlay image
imagedestroy($overlay);
}
}
/**
* Execute a background.
*
* @param integer $r red
* @param integer $g green
* @param integer $b blue
* @param integer $opacity opacity
* @return void
*/
protected function _do_background($r, $g, $b, $opacity)
{
// Loads image if not yet loaded
$this->_load_image();
// Convert an opacity range of 0-100 to 127-0
$opacity = round(abs(($opacity * 127 / 100) - 127));
// Create a new background
$background = $this->_create($this->width, $this->height);
// Allocate the color
$color = imagecolorallocatealpha($background, $r, $g, $b, $opacity);
// Fill the image with white
imagefilledrectangle($background, 0, 0, $this->width, $this->height, $color);
// Alpha blending must be enabled on the background!
imagealphablending($background, TRUE);
// Copy the image onto a white background to remove all transparency
if (imagecopy($background, $this->_image, 0, 0, 0, 0, $this->width, $this->height))
{
// Swap the new image for the old one
imagedestroy($this->_image);
$this->_image = $background;
}
}
/**
* Execute a save.
*
* @param string $file new image filename
* @param integer $quality quality
* @return boolean
*/
protected function _do_save($file, $quality)
{
// Loads image if not yet loaded
$this->_load_image();
// Get the extension of the file
$extension = pathinfo($file, PATHINFO_EXTENSION);
// Get the save function and IMAGETYPE
list($save, $type) = $this->_save_function($extension, $quality);
// Save the image to a file
$status = isset($quality) ? $save($this->_image, $file, $quality) : $save($this->_image, $file);
if ($status === TRUE AND $type !== $this->type)
{
// Reset the image type and mime type
$this->type = $type;
$this->mime = image_type_to_mime_type($type);
}
return TRUE;
}
/**
* Execute a render.
*
* @param string $type image type: png, jpg, gif, etc
* @param integer $quality quality
* @return string
*/
protected function _do_render($type, $quality)
{
// Loads image if not yet loaded
$this->_load_image();
// Get the save function and IMAGETYPE
list($save, $type) = $this->_save_function($type, $quality);
// Capture the output
ob_start();
// Render the image
$status = isset($quality) ? $save($this->_image, NULL, $quality) : $save($this->_image, NULL);
if ($status === TRUE AND $type !== $this->type)
{
// Reset the image type and mime type
$this->type = $type;
$this->mime = image_type_to_mime_type($type);
}
return ob_get_clean();
}
/**
* Get the GD saving function and image type for this extension.
* Also normalizes the quality setting
*
* @param string $extension image type: png, jpg, etc
* @param integer $quality image quality
* @return array save function, IMAGETYPE_* constant
* @throws Kohana_Exception
*/
protected function _save_function($extension, & $quality)
{
if ( ! $extension)
{
// Use the current image type
$extension = image_type_to_extension($this->type, FALSE);
}
switch (strtolower($extension))
{
case 'jpg':
case 'jpeg':
// Save a JPG file
$save = 'imagejpeg';
$type = IMAGETYPE_JPEG;
break;
case 'gif':
// Save a GIF file
$save = 'imagegif';
$type = IMAGETYPE_GIF;
// GIFs do not a quality setting
$quality = NULL;
break;
case 'png':
// Save a PNG file
$save = 'imagepng';
$type = IMAGETYPE_PNG;
// Use a compression level of 9 (does not affect quality!)
$quality = 9;
break;
default:
throw new Kohana_Exception('Installed GD does not support :type images',
array(':type' => $extension));
break;
}
return array($save, $type);
}
/**
* Create an empty image with the given width and height.
*
* @param integer $width image width
* @param integer $height image height
* @return resource
*/
protected function _create($width, $height)
{
// Create an empty image
$image = imagecreatetruecolor($width, $height);
// Do not apply alpha blending
imagealphablending($image, FALSE);
// Save alpha levels
imagesavealpha($image, TRUE);
return $image;
}
} // End Image_GD