Backport asynchronous thumbnail generation from Kabuki.

controllers/EditAsset.php

@@ -76,11 +76,11 @@ class EditAsset extends HTMLController
 						$image->removeAllThumbnails();
 					}
 				}
-				elseif (preg_match('~^thumb_(\d+)x(\d+)(_c[best]?)?$~', $_POST['replacement_target']))
+				elseif (preg_match('~^thumb_(\d+x\d+(?:_c[best]?)?)$~', $_POST['replacement_target'], $match))
 				{
 					$image = $asset->getImage();
-					if (($replace_result = $image->replaceThumbnail($_POST['replacement_target'], $_FILES['replacement']['tmp_name'])) !== 0)
+					if (($replace_result = $image->replaceThumbnail($match[1], $_FILES['replacement']['tmp_name'])) !== 0)
-						throw new Exception('Could not replace thumbnail \'' . $_POST['replacement_target'] . '\' with the uploaded file. Error code: ' . $replace_result);
+						throw new Exception('Could not replace thumbnail \'' . $match[1] . '\' with the uploaded file. Error code: ' . $replace_result);
 				}
 			}
 
@@ -97,12 +97,18 @@ class EditAsset extends HTMLController
 
 	private function getThumbs(Asset $asset)
 	{
-		$path = $asset->getPath();
+		if (!$asset->isImage())
+			return [];
+
+		$image = $asset->getImage();
+		$subdir = $image->getSubdir();
+		$metadata = $image->getMeta();
+		$thumb_selectors = $image->getThumbnails();
+
 		$thumbs = [];
-		$metadata = $asset->getMeta();
+		foreach ($thumb_selectors as $selector => $filename)
-		foreach ($metadata as $key => $meta)
 		{
-			if (!preg_match('~^thumb_(?<width>\d+)x(?<height>\d+)(?<suffix>_c(?<method>[best]?))?$~', $key, $thumb))
+			if (!preg_match('~^(?<width>\d+)x(?<height>\d+)(?<suffix>_c(?<method>[best]?))?$~', $selector, $thumb))
 				continue;
 
 			$has_crop_boundary = isset($metadata['crop_' . $thumb['width'] . 'x' . $thumb['height']]);
@@ -113,10 +119,10 @@ class EditAsset extends HTMLController
 				'crop_method' => !$has_custom_image && !empty($thumb['method']) ? $thumb['method'] : (!empty($thumb['suffix']) ? 'c' : null),
 				'crop_region' => $has_crop_boundary ? $metadata['crop_' . $thumb['width'] . 'x' . $thumb['height']] : null,
 				'custom_image' => $has_custom_image,
-				'filename' => $meta,
+				'filename' => $filename,
-				'full_path' => THUMBSDIR . '/' . $path . '/' . $meta,
+				'full_path' => THUMBSDIR . '/' . $subdir . '/' . $filename,
-				'url' => THUMBSURL . '/' . $path . '/' . $meta,
+				'url' => THUMBSURL . '/' . $subdir . '/' . $filename,
-				'status' => file_exists(THUMBSDIR . '/' . $path . '/' . $meta),
+				'status' => file_exists(THUMBSDIR . '/' . $subdir . '/' . $filename),
 			];
 		}
 

controllers/GenerateThumbnail.php

@@ -0,0 +1,27 @@
+<?php
+/*****************************************************************************
+ * GenerateThumbnail.php
+ * Contains the asynchronous thumbnail generation controller
+ *
+ * Kabuki CMS (C) 2013-2017, Aaron van Geffen
+ *****************************************************************************/
+
+class GenerateThumbnail extends HTMLController
+{
+	public function __construct()
+	{
+		$asset = Asset::fromId($_GET['id']);
+		if (empty($asset) || !$asset->isImage())
+			throw new NotFoundException('Image not found');
+
+		$image = $asset->getImage();
+		$crop_mode = isset($_GET['mode']) ? $_GET['mode'] : false;
+		$url = $image->getThumbnailUrl($_GET['width'], $_GET['height'], $crop_mode, true, true);
+
+		if ($url)
+		{
+			header('Location: ' . $url);
+			exit;
+		}
+	}
+}

migrate_thumbs.php

@@ -0,0 +1,53 @@
+<?php
+/*****************************************************************************
+ * migrate_thumbs.php
+ * Migrates old-style thumbnails (meta) to new table.
+ *
+ * Kabuki CMS (C) 2013-2015, Aaron van Geffen
+ *****************************************************************************/
+
+// Include the project's configuration.
+require_once 'config.php';
+
+// Set up the autoloader.
+require_once 'vendor/autoload.php';
+
+// Initialise the database.
+$db = new Database(DB_SERVER, DB_USER, DB_PASS, DB_NAME);
+Registry::set('db', $db);
+
+// Do some authentication checks.
+Session::start();
+Registry::set('user', Authentication::isLoggedIn() ? Member::fromId($_SESSION['user_id']) : new Guest());
+
+
+$res = $db->query('
+	SELECT id_asset, variable, value
+	FROM assets_meta
+	WHERE variable LIKE {string:thumbs}',
+	['thumbs' => 'thumb_%']);
+
+while ($row = $db->fetch_assoc($res))
+{
+	if (!preg_match('~^thumb_(?<width>\d+)x(?<height>\d+)(?:_(?<mode>c[best]?))?$~', $row['variable'], $match))
+		continue;
+
+	echo 'Migrating ... ', $row['value'], '(#', $row['id_asset'], ")\r";
+
+	$db->insert('replace', 'assets_thumbs', [
+		'id_asset' => 'int',
+		'width' => 'int',
+		'height' => 'int',
+		'mode' => 'string-3',
+		'filename' => 'string-255',
+	], [
+		'id_asset' => $row['id_asset'],
+		'width' => $match['width'],
+		'height' => $match['height'],
+		'mode' => $match['mode'] ?? '',
+		'filename' => $row['value'],
+	]);
+}
+
+echo "\nDone\n";
+

models/Asset.php

@@ -18,8 +18,10 @@ class Asset
 	protected $image_height;
 	protected $date_captured;
 	protected $priority;
+
 	protected $meta;
 	protected $tags;
+	protected $thumbnails;
 
 	protected function __construct(array $data)
 	{
@@ -58,8 +60,10 @@ class Asset
 
 	public static function byRow(array $row, $return_format = 'object')
 	{
+		$db = Registry::get('db');
+
 		// Supplement with metadata.
-		$row['meta'] = Registry::get('db')->queryPair('
+		$row['meta'] = $db->queryPair('
 			SELECT variable, value
 			FROM assets_meta
 			WHERE id_asset = {int:id_asset}',
@@ -67,6 +71,24 @@ class Asset
 				'id_asset' => $row['id_asset'],
 			]);
 
+		// And thumbnails.
+		$row['thumbnails'] = $db->queryPair('
+			SELECT
+				CONCAT(
+					width,
+					{string:x},
+					height,
+					IF(mode != {string:empty}, CONCAT({string:_}, mode), {string:empty})
+				) AS selector, filename
+			FROM assets_thumbs
+			WHERE id_asset = {int:id_asset}',
+			[
+				'id_asset' => $row['id_asset'],
+				'empty' => '',
+				'x' => 'x',
+				'_' => '_',
+			]);
+
 		return $return_format == 'object' ? new Asset($row) : $row;
 	}
 
@@ -91,6 +113,7 @@ class Asset
 		{
 			$assets[$asset['id_asset']] = $asset;
 			$assets[$asset['id_asset']]['meta'] = [];
+			$assets[$asset['id_asset']]['thumbnails'] = [];
 		}
 
 		$metas = $db->queryRows('
@@ -105,6 +128,27 @@ class Asset
 		foreach ($metas as $meta)
 			$assets[$meta[0]]['meta'][$meta[1]] = $meta[2];
 
+		$thumbnails = $db->queryRows('
+			SELECT id_asset,
+				CONCAT(
+					width,
+					{string:x},
+					height,
+					IF(mode != {string:empty}, CONCAT({string:_}, mode), {string:empty})
+				) AS selector, filename
+			FROM assets_thumbs
+			WHERE id_asset IN ({array_int:id_assets})
+			ORDER BY id_asset',
+			[
+				'id_assets' => $id_assets,
+				'empty' => '',
+				'x' => 'x',
+				'_' => '_',
+			]);
+
+		foreach ($thumbnails as $thumb)
+			$assets[$thumb[0]]['thumbnails'][$thumb[1]] = $thumb[2];
+
 		if ($return_format == 'array')
 			return $assets;
 		else
@@ -270,7 +314,7 @@ class Asset
 		return ASSETSDIR . '/' . $this->subdir . '/' . $this->filename;
 	}
 
-	public function getPath()
+	public function getSubdir()
 	{
 		return $this->subdir;
 	}

models/AssetIterator.php

@@ -11,12 +11,14 @@ class AssetIterator extends Asset
 	private $return_format;
 	private $res_assets;
 	private $res_meta;
+	private $res_thumbs;
 
-	protected function __construct($res_assets, $res_meta, $return_format)
+	protected function __construct($res_assets, $res_meta, $res_thumbs, $return_format)
 	{
 		$this->db = Registry::get('db');
 		$this->res_assets = $res_assets;
 		$this->res_meta = $res_meta;
+		$this->res_thumbs = $res_thumbs;
 		$this->return_format = $return_format;
 	}
 
@@ -41,6 +43,19 @@ class AssetIterator extends Asset
 		// Reset internal pointer for next asset.
 		$this->db->data_seek($this->res_meta, 0);
 
+		// Looks up thumbnails.
+		$row['thumbnails'] = [];
+		while ($thumbs = $this->db->fetch_assoc($this->res_thumbs))
+		{
+			if ($thumbs['id_asset'] != $row['id_asset'])
+				continue;
+
+			$row['thumbnails'][$thumbs['selector']] = $thumbs['filename'];
+		}
+
+		// Reset internal pointer for next asset.
+		$this->db->data_seek($this->res_thumbs, 0);
+
 		if ($this->return_format == 'object')
 			return new Asset($row);
 		else
@@ -51,6 +66,7 @@ class AssetIterator extends Asset
 	{
 		$this->db->data_seek($this->res_assets, 0);
 		$this->db->data_seek($this->res_meta, 0);
+		$this->db->data_seek($this->res_thumbs, 0);
 	}
 
 	public function clean()
@@ -135,7 +151,29 @@ class AssetIterator extends Asset
 			ORDER BY id_asset',
 			$params);
 
-		$iterator = new self($res_assets, $res_meta, $return_format);
+		// Get a resource object for the asset thumbs.
+		$res_thumbs = $db->query('
+			SELECT id_asset, filename,
+				CONCAT(
+					width,
+					{string:x},
+					height,
+					IF(mode != {string:empty}, CONCAT({string:_}, mode), {string:empty})
+				) AS selector
+			FROM assets_thumbs
+			WHERE id_asset IN(
+				SELECT id_asset
+				FROM assets AS a
+				WHERE ' . $where . '
+			)
+			ORDER BY id_asset',
+			$params + [
+				'empty' => '',
+				'x' => 'x',
+				'_' => '_',
+			]);
+
+		$iterator = new self($res_assets, $res_meta, $res_thumbs, $return_format);
 
 		// Returning total count, too?
 		if ($return_count)

models/Dispatcher.php

@@ -44,6 +44,12 @@ class Dispatcher
 		{
 			return new ViewPhotoAlbum();
 		}
+		// Asynchronously generating thumbnails?
+		elseif (preg_match('~^/thumbnail/(?<id>\d+)/(?<width>\d+)x(?<height>\d+)(?:_(?<mode>c(t|b|s|)))?/?~', $_SERVER['PATH_INFO'], $path))
+		{
+			$_GET = array_merge($_GET, $path);
+			return new GenerateThumbnail();
+		}
 		// Look for particular actions...
 		elseif (preg_match('~^/(?<action>[a-z]+)(?:/page/(?<page>\d+))?/?~', $_SERVER['PATH_INFO'], $path) && isset($possibleActions[$path['action']]))
 		{

models/Image.php

@@ -82,191 +82,12 @@ class Image extends Asset
 	 * @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 estimation [false].
+	 * @param generate: whether or not to generate a thumbnail if no existing file was found.
 	 */
-	public function getThumbnailUrl($width, $height, $crop = true, $fit = true)
+	public function getThumbnailUrl($width, $height, $crop = true, $fit = true, $generate = false)
 	{
-		// First, assert the image's dimensions are properly known in the database.
+		$thumbnail = new Thumbnail($this);
-		if (!isset($this->image_height, $this->image_width))
+		return $thumbnail->getUrl($width, $height, $crop, $fit, $generate);
-			throw new UnexpectedValueException('Image width or height is undefined -- inconsistent database?');
-
-		// Inferring width or height?
-		if (!$height)
-			$height = ceil($width / $this->image_width * $this->image_height);
-		elseif (!$width)
-			$width = ceil($height / $this->image_height * $this->image_width);
-
-		// Inferring the height from the original image's ratio?
-		if (!$fit)
-			$height = floor($width / ($this->image_width / $this->image_height));
-
-		// Assert we have both, now...
-		if (empty($width) || empty($height))
-			throw new InvalidArgumentException('Expecting at least either width or height as argument.');
-
-		// If we're cropping, verify we're in the right mode.
-		if ($crop)
-		{
-			// If the original image's aspect ratio is much wider, take a slice instead.
-			if ($this->image_width / $this->image_height > $width / $height)
-				$crop = 'slice';
-
-			// We won't be cropping if the thumbnail is proportional to its original.
-			if (abs($width / $height - $this->image_width / $this->image_height) <= 0.05)
-				$crop = false;
-		}
-
-		// Do we have an exact crop boundary for these dimensions?
-		$crop_selector = "crop_{$width}x{$height}";
-		if (isset($this->meta[$crop_selector]))
-			$crop = 'exact';
-
-		// Now, do we need to suffix the filename?
-		if ($crop)
-			$suffix = '_c' . (is_string($crop) && $crop !== 'center' ? substr($crop, 0, 1) : '');
-		else
-			$suffix = '';
-
-		// Check whether we already resized this earlier.
-		$thumb_selector = "thumb_{$width}x{$height}{$suffix}";
-		if (isset($this->meta[$thumb_selector]) && file_exists(THUMBSDIR . '/' . $this->subdir . '/' . $this->meta[$thumb_selector]))
-			return THUMBSURL . '/' . $this->subdir . '/' . $this->meta[$thumb_selector];
-
-		// Do we have a custom thumbnail on file?
-		$custom_selector = "custom_{$width}x{$height}";
-		if (isset($this->meta[$custom_selector]))
-		{
-			if (file_exists(ASSETSDIR . '/' . $this->subdir . '/' . $this->meta[$custom_selector]))
-			{
-				// Copy the custom thumbail to the general thumbnail directory.
-				copy(ASSETSDIR . '/' . $this->subdir . '/' . $this->meta[$custom_selector],
-					THUMBSDIR . '/' . $this->subdir . '/' . $this->meta[$custom_selector]);
-
-				// Let's remember this for future reference.
-				$this->meta[$thumb_selector] = $this->meta[$custom_selector];
-				$this->save();
-
-				return THUMBSURL . '/' . $this->subdir . '/' . $this->meta[$custom_selector];
-			}
-			else
-				throw new UnexpectedValueException('Custom thumbnail expected, but missing in file system!');
-		}
-
-		// 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->subdir . '/' . $this->filename);
-
-			// The image might have some orientation set through EXIF. Let's apply this first.
-			self::applyRotation($thumb);
-
-			// Just resizing? Easy peasy.
-			if (!$crop)
-				$thumb->resizeImage($width, $height, Imagick::FILTER_LANCZOS, 1);
-			// Cropping in the center?
-			elseif ($crop === true || $crop === 'center')
-				$thumb->cropThumbnailImage($width, $height);
-			// Exact cropping? We can do that.
-			elseif ($crop === 'exact')
-			{
-				list($crop_width, $crop_height, $crop_x_pos, $crop_y_pos) = explode(',', $this->meta[$crop_selector]);
-				$thumb->cropImage($crop_width, $crop_height, $crop_x_pos, $crop_y_pos);
-				$thumb->resizeImage($width, $height, Imagick::FILTER_LANCZOS, 1);
-			}
-			// Advanced cropping? Fun!
-			else
-			{
-				$size = $thumb->getImageGeometry();
-
-				// Taking a horizontal slice from the top or bottom of the original image?
-				if ($crop === 'top' || $crop === 'bottom')
-				{
-					$crop_width = $size['width'];
-					$crop_height = floor($size['width'] / $width * $height);
-					$target_x = 0;
-					$target_y = $crop === 'top' ? 0 : $size['height'] - $crop_height;
-				}
-				// Otherwise, we're taking a vertical slice from the centre.
-				else
-				{
-					$crop_width = floor($size['height'] / $height * $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);
-				$thumb->resizeImage($width, $height, Imagick::FILTER_LANCZOS, 1);
-			}
-
-			// What sort of image is this? Fall back to PNG if we must.
-			switch ($thumb->getImageFormat())
-			{
-				case 'JPEG':
-					$ext = 'jpg';
-					$thumb->setImageCompressionQuality(60);
-					break;
-
-				case 'GIF':
-					$ext = 'gif';
-					break;
-
-				case 'PNG':
-				default:
-					$thumb->setFormat('PNG');
-					$ext = 'png';
-					break;
-			}
-
-			// So, how do we name this?
-			$thumbfilename = substr($this->filename, 0, strrpos($this->filename, '.')) . "_{$width}x{$height}{$suffix}.$ext";
-
-			// Ensure the thumbnail subdirectory exists.
-			if (!is_dir(THUMBSDIR . '/' . $this->subdir))
-				mkdir(THUMBSDIR . '/' . $this->subdir, 0755, true);
-
-			// Save it in a public spot.
-			$thumb->writeImage(THUMBSDIR . '/' . $this->subdir . '/' . $thumbfilename);
-			$thumb->clear();
-			$thumb->destroy();
-		}
-		// Blast! Curse your sudden but inevitable betrayal!
-		catch (ImagickException $e)
-		{
-			throw new Exception('ImageMagick error occurred while generating thumbnail. Output: ' . $e->getMessage());
-		}
-
-		// Let's remember this for future reference.
-		$this->meta[$thumb_selector] = $thumbfilename;
-		$this->save();
-
-		// Ah yes, you wanted a URL, didn't you...
-		return THUMBSURL . '/' . $this->subdir . '/' . $this->meta[$thumb_selector];
-	}
-
-	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);
 	}
 
 	public function bestColor()
@@ -299,6 +120,11 @@ class Image extends Asset
 		return $this->meta['best_color_label'];
 	}
 
+	public function getId()
+	{
+		return $this->id_asset;
+	}
+
 	public function width()
 	{
 		return $this->image_width;
@@ -309,37 +135,45 @@ class Image extends Asset
 		return $this->image_height;
 	}
 
+	public function ratio()
+	{
+		return $this->image_width / $this->image_height;
+	}
+
 	public function isPanorama()
 	{
-		return $this->image_width / $this->image_height > 2;
+		return $this->ratio() >= 2;
 	}
 
 	public function isPortrait()
 	{
-		return $this->image_width / $this->image_height < 1;
+		return $this->ratio() < 1;
 	}
 
 	public function isLandscape()
 	{
-		$ratio = $this->image_width / $this->image_height;
+		$ratio = $this->ratio();
 		return $ratio >= 1 && $ratio <= 2;
 	}
 
+	public function getThumbnails()
+	{
+		return $this->thumbnails;
+	}
+
 	public function removeAllThumbnails()
 	{
-		foreach ($this->meta as $key => $value)
+		foreach ($this->thumbnails as $key => $value)
 		{
-			if (substr($key, 0, 6) !== 'thumb_')
-				continue;
-
 			$thumb_path = THUMBSDIR . '/' . $this->subdir . '/' . $value;
 			if (is_file($thumb_path))
 				unlink($thumb_path);
-
-			unset($this->meta[$key]);
 		}
 
-		$this->saveMetaData();
+		return Registry::get('db')->query('
+			DELETE FROM assets_thumbs
+			WHERE id_asset = {int:id_asset}',
+			['id_asset' => $this->id_asset]);
 	}
 
 	public function replaceThumbnail($descriptor, $tmp_file)
@@ -347,7 +181,7 @@ class Image extends Asset
 		if (!is_file($tmp_file))
 			return -1;
 
-		if (!isset($this->meta[$descriptor]))
+		if (!isset($this->thumbnails[$descriptor]))
 			return -2;
 
 		$image = new Imagick($tmp_file);
@@ -355,12 +189,12 @@ class Image extends Asset
 		unset($image);
 
 		// Check whether dimensions match.
-		$test_descriptor = 'thumb_' . $d['width'] . 'x' . $d['height'];
+		$test_descriptor = $d['width'] . 'x' . $d['height'];
 		if ($descriptor !== $test_descriptor && strpos($descriptor, $test_descriptor . '_') === false)
 			return -3;
 
 		// Save the custom thumbnail in the assets directory.
-		$destination = ASSETSDIR . '/' . $this->subdir . '/' . $this->meta[$descriptor];
+		$destination = ASSETSDIR . '/' . $this->subdir . '/' . $this->thumbnails[$descriptor];
 		if (file_exists($destination) && !is_writable($destination))
 			return -4;
 
@@ -368,7 +202,7 @@ class Image extends Asset
 			return -5;
 
 		// Copy it to the thumbnail directory, overwriting the automatically generated one, too.
-		$destination = THUMBSDIR . '/' . $this->subdir . '/' . $this->meta[$descriptor];
+		$destination = THUMBSDIR . '/' . $this->subdir . '/' . $this->thumbnails[$descriptor];
 		if (file_exists($destination) && !is_writable($destination))
 			return -6;
 
@@ -376,7 +210,7 @@ class Image extends Asset
 			return -7;
 
 		// A little bookkeeping
-		$this->meta['custom_' . $d['width'] . 'x' . $d['height']] = $this->meta[$descriptor];
+		$this->meta['custom_' . $d['width'] . 'x' . $d['height']] = $this->thumbnails[$descriptor];
 		$this->saveMetaData();
 		return 0;
 	}

models/Thumbnail.php

@@ -0,0 +1,344 @@
+<?php
+/*****************************************************************************
+ * Thumbnail.php
+ * Contains key class Thumbnail.
+ *
+ * Kabuki CMS (C) 2013-2015, Aaron van Geffen
+ *****************************************************************************/
+
+class Thumbnail
+{
+	private $image;
+	private $thumbnails;
+
+	private $properly_initialised;
+	private $width;
+	private $height;
+	private $crop_mode;
+
+	const CROP_MODE_NONE         = 0;
+	const CROP_MODE_BOUNDARY     = 1;
+	const CROP_MODE_CUSTOM_FILE  = 2;
+	const CROP_MODE_SLICE_TOP    = 3;
+	const CROP_MODE_SLICE_CENTRE = 4;
+	const CROP_MODE_SLICE_BOTTOM = 5;
+
+	public function __construct($image)
+	{
+		$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]))
+		{
+			if (file_exists(THUMBSDIR . '/' . $this->image->getSubdir() . '/' . $this->thumbnails[$thumb_selector]))
+				return THUMBSURL . '/' . $this->image->getSubdir() . '/' . $this->thumbnails[$thumb_selector];
+		}
+
+		// Do we have a custom thumbnail on file?
+		$custom_selector = 'custom_' . $this->width . 'x' . $this->height;
+		if (isset($this->image_meta[$custom_selector]))
+		{
+			if (file_exists(ASSETSDIR . '/' . $this->image->getSubdir() . '/' . $this->image_meta[$custom_selector]))
+			{
+				// Copy the custom thumbail to the general thumbnail directory.
+				copy(ASSETSDIR . '/' . $this->image->getSubdir() . '/' . $this->image_meta[$custom_selector],
+					THUMBSDIR . '/' . $this->image->getSubdir() . '/' . $this->image_meta[$custom_selector]);
+
+				// Let's remember this for future reference.
+				$this->markAsGenerated($this->image_meta[$custom_selector]);
+
+				return THUMBSURL . '/' . $this->image->getSubdir() . '/' . $this->image_meta[$custom_selector];
+			}
+			else
+				throw new UnexpectedValueException('Custom thumbnail expected, but missing in file system!');
+		}
+
+		// Is this the right moment to generate a thumbnail, then?
+		if ($generate && array_key_exists($thumb_selector, $this->thumbnails))
+		{
+			return $this->generate();
+		}
+
+		// If not, queue it for generation at another time, and return a URL to generate it with.
+		elseif (!$generate)
+		{
+			$this->markAsQueued();
+			return BASEURL . '/thumbnail/' . $this->image->getId() . '/' . $this->width . 'x' . $this->height . $this->filename_suffix . '/';
+		}
+
+		// Still here..? What are you up to? ..Sneaking?
+		else
+		{
+			throw new Exception("Trying to generate a thumbnail for values that were not previously initialised by the system?\n" . print_r(func_get_args(), true));
+		}
+	}
+
+	/**
+	 * @param width: width of the thumbnail.
+	 * @param height: height of the thumbnail.
+	 * @param crop: whether and how to crop original image to fit. [false|true|'top'|'center'|'bottom']
+	 * @param fit: whether to fit the image to given boundaries [true], or use them merely as an estimate [false].
+	 */
+	private function init($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]))
+				$this->crop_mode = self::CROP_MODE_BOUNDARY;
+
+			// If the original image's aspect ratio is much wider, take a slice instead.
+			if ($this->image->ratio() > $this->ratio())
+				$this->crop_mode = self::CROP_MODE_SLICE_CENTRE;
+
+			// We won't be cropping if the thumbnail is proportional to its original.
+			elseif (abs($this->ratio() - $this->image->ratio()) <= 0.025)
+				$this->crop_mode = self::CROP_MODE_NONE;
+
+			// Slice from the top?
+			elseif ($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';
+		}
+		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.
+			if (!is_dir(THUMBSDIR . '/' . $this->image->getSubdir()))
+				mkdir(THUMBSDIR . '/' . $this->image->getSubdir(), 0755, true);
+
+			// Save it in a public spot.
+			$thumb->writeImage(THUMBSDIR . '/' . $this->image->getSubdir() . '/' . $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;
+		}
+		// Blast! Curse your sudden but inevitable betrayal!
+		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 : '';
+		}
+
+		return $success;
+	}
+
+	private function markAsQueued()
+	{
+		$this->updateDb('NULL');
+	}
+
+	private function markAsGenerated($filename)
+	{
+		$this->updateDb($filename);
+	}
+}

templates/EditAssetForm.php

@@ -279,7 +279,7 @@ class EditAssetForm extends SubTemplate
 				echo ' crop';
 			}
 			elseif ($thumb['custom_image'])
-				echo ' (custom)';
+				echo ', custom';
 
 			echo ')
 						</option>';