pics/models/Thumbnail.php

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<?php
/*****************************************************************************
* Thumbnail.php
* Contains key class Thumbnail.
*
* Kabuki CMS (C) 2013-2020, Aaron van Geffen
*****************************************************************************/
class Thumbnail
{
private $image;
private $image_meta;
private $thumbnails;
private $properly_initialised;
private $width;
private $height;
private $crop_mode;
private string $filename_suffix;
const CROP_MODE_NONE = 0;
const CROP_MODE_BOUNDARY = 1;
const CROP_MODE_CUSTOM_FILE = 2;
const CROP_MODE_SLICE_TOP = 3;
const CROP_MODE_SLICE_CENTRE = 4;
const CROP_MODE_SLICE_BOTTOM = 5;
public function __construct(Image $image)
{
$this->image = $image;
$this->image_meta = $image->getMeta();
$this->thumbnails = $image->getThumbnails();
}
/**
* @param width: width of the thumbnail.
* @param height: height of the thumbnail.
* @param crop: whether and how to crop original image to fit. [false|true|'top'|'center'|'bottom']
* @param fit: whether to fit the image to given boundaries [true], or use them merely as an estimate [false].
* @param generate: whether or not to generate a thumbnail if no existing file was found.
*/
public function getUrl($width, $height, $crop = true, $fit = true, $generate = false)
{
$this->init($width, $height, $crop, $fit);
// Check whether we've already resized this earlier.
$thumb_selector = $this->width . 'x' . $this->height . $this->filename_suffix;
if (!empty($this->thumbnails[$thumb_selector]))
{
$thumb_filename = $this->image->getSubdir() . '/' . $this->thumbnails[$thumb_selector];
if (file_exists(THUMBSDIR . '/' . $thumb_filename))
return THUMBSURL . '/' . $thumb_filename;
}
// Do we have a custom thumbnail on file?
$custom_selector = 'custom_' . $this->width . 'x' . $this->height;
if (isset($this->image_meta[$custom_selector]))
{
$custom_filename = $this->image->getSubdir() . '/' . $this->image_meta[$custom_selector];
if (file_exists(ASSETSDIR . '/' . $custom_filename))
{
// Copy the custom thumbail to the general thumbnail directory.
copy(ASSETSDIR . '/' . $custom_filename, THUMBSDIR . '/' . $custom_filename);
// Let's remember this for future reference.
$this->markAsGenerated($this->image_meta[$custom_selector]);
return THUMBSURL . '/' . $custom_filename;
}
else
throw new UnexpectedValueException('Custom thumbnail expected, but missing in file system!');
}
// Is this the right moment to generate a thumbnail, then?
if ($generate)
{
if (array_key_exists($thumb_selector, $this->thumbnails))
return $this->generate();
else
throw new Exception("Trying to generate a thumbnail not previously queued by the system\n" .
print_r(func_get_args(), true));
}
// If not, queue it for generation at another time, and return a URL to generate it with.
else
{
$this->markAsQueued();
return BASEURL . '/thumbnail/' . $this->image->getId() . '/' . $thumb_selector . '/';
}
}
/**
* @param width: width of the thumbnail.
* @param height: height of the thumbnail.
* @param crop: whether and how to crop original image to fit. [false|true|'top'|'center'|'bottom']
* @param fit: whether to fit the image to given boundaries [true], or use them merely as an estimate [false].
*/
private function init($width, $height, $crop = true, $fit = true)
{
$this->properly_initialised = false;
// First, assert the image's dimensions are properly known in the database.
if ($this->image->width() === null || $this->image->height() === null)
throw new UnexpectedValueException('Image width or height is undefined -- inconsistent database?');
$this->width = $width;
$this->height = $height;
// Inferring width or height?
if (!$this->height)
$this->height = ceil($this->width / $this->image->ratio());
elseif (!$this->width)
$this->width = ceil($this->height * $this->image->ratio());
// Inferring the height from the original image's ratio?
if (!$fit)
$this->height = floor($this->width / $this->image->ratio());
// Assert we have both, now...
if (empty($this->width) || empty($this->height))
throw new InvalidArgumentException('Expecting at least either width or height as argument.');
// If we're cropping, verify we're in the right mode.
if ($crop)
{
// Do we have an exact crop boundary set for these dimensions?
$crop_selector = 'crop_' . $this->width . 'x' . $this->height;
if (isset($this->image_meta[$crop_selector]))
$this->crop_mode = self::CROP_MODE_BOUNDARY;
// We won't be cropping if the thumbnail is proportional to its original.
elseif (abs($this->ratio() - $this->image->ratio()) <= 0.025)
$this->crop_mode = self::CROP_MODE_NONE;
// If the original image's aspect ratio is much wider, take a slice instead.
elseif ($this->image->ratio() > $this->ratio())
$this->crop_mode = self::CROP_MODE_SLICE_CENTRE;
// Slice from the top?
elseif ($crop === 'top' || $crop === 'ct')
$this->crop_mode = self::CROP_MODE_SLICE_TOP;
// Slice from the bottom?
elseif ($crop === 'bottom' || $crop === 'cb')
$this->crop_mode = self::CROP_MODE_SLICE_BOTTOM;
// Slice from the centre?
elseif ($crop === 'centre' || $crop === 'center' || $crop === 'cs' || $crop === true)
$this->crop_mode = self::CROP_MODE_SLICE_CENTRE;
// Unexpected value? Assume no crop.
else
$this->crop_mode = self::CROP_MODE_NONE;
}
else
$this->crop_mode = self::CROP_MODE_NONE;
// Now, do we need to suffix the filename?
if ($this->crop_mode !== self::CROP_MODE_NONE)
{
$this->filename_suffix = '_c';
if ($this->crop_mode === self::CROP_MODE_SLICE_TOP)
$this->filename_suffix .= 't';
elseif ($this->crop_mode === self::CROP_MODE_SLICE_CENTRE)
$this->filename_suffix .= 's';
elseif ($this->crop_mode === self::CROP_MODE_SLICE_BOTTOM)
$this->filename_suffix .= 'b';
elseif ($this->crop_mode === self::CROP_MODE_BOUNDARY)
$this->filename_suffix .= 'e';
}
else
$this->filename_suffix = '';
$this->properly_initialised = true;
}
private function generate()
{
if (!$this->properly_initialised)
throw new UnexpectedValueException('The thumbnail factory was not intialised before use!');
// Let's try some arcane stuff...
try
{
if (!class_exists('Imagick'))
throw new Exception("The PHP module 'imagick' appears to be disabled. Please enable it to use image resampling functions.");
$thumb = new Imagick(ASSETSDIR . '/' . $this->image->getSubdir() . '/' . $this->image->getFilename());
// The image might have some orientation set through EXIF. Let's apply this first.
self::applyRotation($thumb);
// Just resizing? Easy peasy.
if ($this->crop_mode === self::CROP_MODE_NONE)
$thumb->resizeImage($this->width, $this->height, Imagick::FILTER_LANCZOS, 1);
// // Cropping in the center?
elseif ($this->crop_mode === self::CROP_MODE_SLICE_CENTRE)
$thumb->cropThumbnailImage($this->width, $this->height);
// Exact cropping? We can do that.
elseif ($this->crop_mode === self::CROP_MODE_BOUNDARY)
{
$crop_selector = 'crop_' . $this->width . 'x' . $this->height;
list($crop_width, $crop_height, $crop_x_pos, $crop_y_pos) = explode(',', $this->image_meta[$crop_selector]);
$thumb->cropImage($crop_width, $crop_height, $crop_x_pos, $crop_y_pos);
$thumb->resizeImage($this->width, $this->height, Imagick::FILTER_LANCZOS, 1);
}
// Advanced cropping? Fun!
else
{
$size = $thumb->getImageGeometry();
// Taking a horizontal slice from the top or bottom of the original image?
if ($this->crop_mode === self::CROP_MODE_SLICE_TOP || $this->crop_mode === self::CROP_MODE_SLICE_BOTTOM)
{
$crop_width = $size['width'];
$crop_height = floor($size['width'] / $this->width * $this->height);
$target_x = 0;
$target_y = $this->crop_mode === self::CROP_MODE_SLICE_TOP ? 0 : $size['height'] - $crop_height;
}
// Otherwise, we're taking a vertical slice from the centre.
else
{
$crop_width = floor($size['height'] / $this->height * $this->width);
$crop_height = $size['height'];
$target_x = floor(($size['width'] - $crop_width) / 2);
$target_y = 0;
}
$thumb->cropImage($crop_width, $crop_height, $target_x, $target_y);
$thumb->resizeImage($this->width, $this->height, Imagick::FILTER_LANCZOS, 1);
}
// What sort of image is this? Fall back to PNG if we must.
switch ($thumb->getImageFormat())
{
case 'JPEG':
$ext = 'jpg';
break;
case 'GIF':
$ext = 'gif';
break;
case 'PNG':
default:
$thumb->setFormat('PNG');
$ext = 'png';
break;
}
// So, how do we name this?
$thumb_filename = substr($this->image->getFilename(), 0, strrpos($this->image->getFilename(), '.')) .
'_' . $this->width . 'x' . $this->height . $this->filename_suffix . '.' . $ext;
// Ensure the thumbnail subdirectory exists.
$target_dir = THUMBSDIR . '/' . $this->image->getSubdir();
if (!is_dir($target_dir))
mkdir($target_dir, 0755, true);
if (!is_writable($target_dir))
throw new Exception('Thumbnail directory is not writable!');
// No need to preserve every detail.
$thumb->setImageCompressionQuality(80);
// Save it in a public spot.
$thumb->writeImage($target_dir . '/' . $thumb_filename);
// Let's remember this for future reference...
$this->markAsGenerated($thumb_filename);
$thumb->clear();
$thumb->destroy();
// Finally, return the URL for the generated thumbnail image.
return THUMBSURL . '/' . $this->image->getSubdir() . '/' . $thumb_filename;
}
catch (ImagickException $e)
{
throw new Exception('ImageMagick error occurred while generating thumbnail. Output: ' . $e->getMessage());
}
}
private static function applyRotation(Imagick $image)
{
switch ($image->getImageOrientation())
{
// Clockwise rotation
case Imagick::ORIENTATION_RIGHTTOP:
$image->rotateImage("#000", 90);
break;
// Counter-clockwise rotation
case Imagick::ORIENTATION_LEFTBOTTOM:
$image->rotateImage("#000", 270);
break;
// Upside down?
case Imagick::ORIENTATION_BOTTOMRIGHT:
$image->rotateImage("#000", 180);
}
// Having rotated the image, make sure the EXIF data is set properly.
$image->setImageOrientation(Imagick::ORIENTATION_TOPLEFT);
}
private function ratio()
{
return $this->width / $this->height;
}
private function updateDb($filename)
{
if (!$this->properly_initialised)
throw new UnexpectedValueException('The thumbnail factory was not intialised before use!');
$mode = !empty($this->filename_suffix) ? substr($this->filename_suffix, 1) : '';
$success = Registry::get('db')->insert('replace', 'assets_thumbs', [
'id_asset' => 'int',
'width' => 'int',
'height' => 'int',
'mode' => 'string-3',
'filename' => 'string-255',
], [
'id_asset' => $this->image->getId(),
'width' => $this->width,
'height' => $this->height,
'mode' => $mode,
'filename' => $filename,
]);
if ($success)
{
$thumb_selector = $this->width . 'x' . $this->height . $this->filename_suffix;
$this->thumbnails[$thumb_selector] = $filename !== 'NULL' ? $filename : null;
// For consistency, write new thumbnail filename to parent Image object.
// TODO: there could still be an inconsistency if multiple objects exists for the same image asset.
$this->image->getThumbnails()[$thumb_selector] = $this->thumbnails[$thumb_selector];
return $success;
}
else
throw new UnexpectedValueException('Thumbnail queuing query failed');
}
private function markAsQueued()
{
$this->updateDb('NULL');
}
private function markAsGenerated($filename)
{
$this->updateDb($filename);
}
}