silverstripe-framework/filesystem/GD.php

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<?php
/**
* A wrapper class for GD-based images, with lots of manipulation functions.
*/
class GD extends Object {
protected $gd, $width, $height;
protected $quality = 75;
function __construct($filename = null) {
// If we're working with image resampling, things could take a while. Bump up the time-limit
set_time_limit(300);
if($filename) {
// We use getimagesize instead of extension checking, because sometimes extensions are wrong.
list($width, $height, $type, $attr) = getimagesize($filename);
switch($type) {
case 1: $this->setGD(imagecreatefromgif($filename)); break;
case 2: $this->setGD(imagecreatefromjpeg($filename)); break;
case 3: $this->setGD(imagecreatefrompng($filename)); break;
}
}
parent::__construct();
}
protected function setGD($gd) {
$this->gd = $gd;
$this->width = imagesx($gd);
$this->height = imagesy($gd);
}
/**
* Set the image quality, used when saving JPEGs.
*/
function setQuality($quality) {
$this->quality = $quality;
}
/**
* Resize an image to cover the given width/height completely, and crop off any overhanging edges.
*/
function croppedResize($width, $height) {
if(!$this->gd) return;
$width = round($width);
$height = round($height);
$newGD = imagecreatetruecolor($width, $height);
// Preserves transparency between images
imagealphablending($newGD, false);
imagesavealpha($newGD, true);
$destAR = $width / $height;
if ($this->width > 0 && $this->height > 0 ){
// We can't divide by zero theres something wrong.
$srcAR = $this->width / $this->height;
// Destination narrower than the source
if($destAR < $srcAR) {
$srcY = 0;
$srcHeight = $this->height;
$srcWidth = $this->height * $destAR;
$srcX = ($this->width - $srcWidth) / 2;
// Destination shorter than the source
} else {
$srcX = 0;
$srcWidth = $this->width;
$srcHeight = $this->width / $destAR;
$srcY = ($this->height - $srcHeight) / 2;
}
imagecopyresampled($newGD, $this->gd, 0,0, $srcX, $srcY, $width, $height, $srcWidth, $srcHeight);
}
$output = new GD();
$output->setGD($newGD);
return $output;
}
/**
* Resizes the image to fit within the given region.
* Behaves similarly to paddedResize but without the padding.
* @todo This method isn't very efficent
*/
function fittedResize($width, $height) {
$gd = $this->resizeByHeight($height);
if($gd->width > $width) $gd = $gd->resizeByWidth($width);
return $gd;
}
function hasGD() {
return $this->gd ? true : false;
}
/**
* Resize an image, skewing it as necessary.
*/
function resize($width, $height) {
if(!$this->gd) return;
$width = round($width);
$height = round($height);
if(!$width && !$height) user_error("No dimensions given", E_USER_ERROR);
if(!$width) user_error("Width not given", E_USER_ERROR);
if(!$height) user_error("Height not given", E_USER_ERROR);
$newGD = imagecreatetruecolor($width, $height);
// Preserves transparency between images
imagealphablending($newGD, false);
imagesavealpha($newGD, true);
imagecopyresampled($newGD, $this->gd, 0,0, 0, 0, $width, $height, $this->width, $this->height);
$output = new GD();
$output->setGD($newGD);
return $output;
}
/**
* Resize an image by width. Preserves aspect ratio.
*/
function resizeByWidth( $width ) {
$heightScale = $width / $this->width;
return $this->resize( $width, $heightScale * $this->height );
}
/**
* Resize an image by height. Preserves aspect ratio
*/
function resizeByHeight( $height ) {
$scale = $height / $this->height;
return $this->resize( $scale * $this->width, $height );
}
/**
* Resize the image by preserving aspect ratio. By default, it will keep the image inside the maxWidth and maxHeight
* Passing useAsMinimum will make the smaller dimension equal to the maximum corresponding dimension
*/
function resizeRatio( $maxWidth, $maxHeight, $useAsMinimum = false ) {
$widthRatio = $maxWidth / $this->width;
$heightRatio = $maxHeight / $this->height;
if( $widthRatio < $heightRatio )
return $useAsMinimum ? $this->resizeByHeight( $maxHeight ) : $this->resizeByWidth( $maxWidth );
else
return $useAsMinimum ? $this->resizeByWidth( $maxWidth ) : $this->resizeByHeight( $maxHeight );
}
static function color_web2gd($image, $webColor) {
if(substr($webColor,0,1) == "#") $webColor = substr($webColor,1);
$r = hexdec(substr($webColor,0,2));
$g = hexdec(substr($webColor,2,2));
$b = hexdec(substr($webColor,4,2));
return imagecolorallocate($image, $r, $g, $b);
}
/**
* Resize to fit fully within the given box, without resizing. Extra space left around
* the image will be padded with the background color.
* @param width
* @param height
* @param backgroundColour
*/
function paddedResize($width, $height, $backgroundColor = "FFFFFF") {
if(!$this->gd) return;
$width = round($width);
$height = round($height);
$newGD = imagecreatetruecolor($width, $height);
// Preserves transparency between images
imagealphablending($newGD, false);
imagesavealpha($newGD, true);
$bg = GD::color_web2gd($newGD, $backgroundColor);
imagefilledrectangle($newGD, 0, 0, $width, $height, $bg);
$destAR = $width / $height;
if ($this->width > 0 && $this->height > 0) {
// We can't divide by zero theres something wrong.
$srcAR = $this->width / $this->height;
// Destination narrower than the source
if($destAR > $srcAR) {
$destY = 0;
$destHeight = $height;
$destWidth = $height * $srcAR;
$destX = ($width - $destWidth) / 2;
// Destination shorter than the source
} else {
$destX = 0;
$destWidth = $width;
$destHeight = $width / $srcAR;
$destY = ($height - $destHeight) / 2;
}
imagecopyresampled($newGD, $this->gd, $destX, $destY, 0, 0, $destWidth, $destHeight, $this->width, $this->height);
}
$output = new GD();
$output->setGD($newGD);
return $output;
}
/**
* Make the image greyscale
* $rv = red value, defaults to 38
* $gv = green value, defaults to 36
* $bv = blue value, defaults to 26
* Based (more or less entirely, with changes for readability) on code from http://www.teckis.com/scriptix/thumbnails/teck.html
*/
function greyscale($rv=38, $gv=36, $bv=26) {
$width = $this->width;
$height = $this->height;
$newGD = imagecreatetruecolor($this->width, $this->height);
$rt = $rv + $bv + $gv;
$rr = ($rv == 0) ? 0 : 1/($rt/$rv);
$br = ($bv == 0) ? 0 : 1/($rt/$bv);
$gr = ($gv == 0) ? 0 : 1/($rt/$gv);
for($dy = 0; $dy <= $height; $dy++) {
for($dx = 0; $dx <= $width; $dx++) {
$pxrgb = imagecolorat($this->gd, $dx, $dy);
$heightgb = ImageColorsforIndex($this->gd, $pxrgb);
$newcol = ($rr*$heightgb['red']) + ($br*$heightgb['blue']) + ($gr*$heightgb['green']);
$setcol = ImageColorAllocate($newGD, $newcol, $newcol, $newcol);
imagesetpixel($newGD, $dx, $dy, $setcol);
}
}
// imagecopyresampled($newGD, $this->gd, 0,0, $srcX, $srcY, $width, $height, $srcWidth, $srcHeight);
$output = new GD();
$output->setGD($newGD);
if($this->quality) $output->setQuality($this->quality);
return $output;
}
function makeDir($dirname) {
if(!file_exists(dirname($dirname))) $this->makeDir(dirname($dirname));
if(!file_exists($dirname)) mkdir($dirname, 02775);
}
function writeTo($filename) {
$this->makeDir(dirname($filename));
if($filename) {
if(file_exists($filename)) list($width, $height, $type, $attr) = getimagesize($filename);
if(file_exists($filename)) unlink($filename);
$ext = strtolower(substr($filename, strrpos($filename,'.')+1));
if(!isset($type)) switch($ext) {
case "gif": $type = 1; break;
case "jpeg": case "jpg": case "jpe": $type = 2; break;
default: $type = 3; break;
}
// if the extension does not exist, the file will not be created!
switch($type) {
case 1: imagegif($this->gd, $filename); break;
case 2: imagejpeg($this->gd, $filename, $this->quality); break;
// case 3, and everything else
default:
// Save them as 8-bit images
// imagetruecolortopalette($this->gd, false, 256);
imagepng($this->gd, $filename); break;
}
if(file_exists($filename)) @chmod($filename,0664);
}
}
}
?>