Apply the metrics and the collection font a fontdata entry sets to the font it registers (#321)

src/Mpdf.php

@@ -4039,13 +4039,13 @@ private function registerFont($fontkey, $family, array $font)
 
 		// Override with values from config_font.php
 		if (isset($this->fontdata[$family]['Ascent']) && $this->fontdata[$family]['Ascent']) {
-			$desc['Ascent'] = $this->fontdata[$family]['Ascent'];
+			$font['desc']['Ascent'] = $this->fontdata[$family]['Ascent'];
 		}
 		if (isset($this->fontdata[$family]['Descent']) && $this->fontdata[$family]['Descent']) {
-			$desc['Descent'] = $this->fontdata[$family]['Descent'];
+			$font['desc']['Descent'] = $this->fontdata[$family]['Descent'];
 		}
 		if (isset($this->fontdata[$family]['Leading']) && $this->fontdata[$family]['Leading']) {
-			$desc['Leading'] = $this->fontdata[$family]['Leading'];
+			$font['desc']['Leading'] = $this->fontdata[$family]['Leading'];
 		}
 
 		$i = count($this->fonts) + $this->extraFontSubsets + 1;
@@ -4173,7 +4173,7 @@ public function fontMetrics($family, $style)
 		$ttffile = $this->fontFileFinder->findFontFile($this->fontdata[$family][$stylekey]);
 		$ttfstat = stat($ttffile);
 
-		$TTCfontID = isset($this->fontdata[$family]['TTCfontID'][$stylekey]) ? isset($this->fontdata[$family]['TTCfontID'][$stylekey]) : 0;
+		$TTCfontID = isset($this->fontdata[$family]['TTCfontID'][$stylekey]) ? $this->fontdata[$family]['TTCfontID'][$stylekey] : 0;
 		$fontUseOTL = isset($this->fontdata[$family]['useOTL']) ? $this->fontdata[$family]['useOTL'] : false;
 		$BMPonly = in_array($family, $this->BMPonly) ? true : false;
 
@@ -4196,6 +4196,12 @@ public function fontMetrics($family, $style)
 			$regenerate = true;
 		} // mPDF 6
 
+		/* The cache may hold another font of the same collection. Compared as integers because caches
+		 * written from v7.1.8 until #321 stored true for every configured TTCfontID, and true == 2 */
+		if ((int) (isset($font['TTCfontID']) ? $font['TTCfontID'] : 0) !== (int) $TTCfontID) {
+			$regenerate = true;
+		}
+
 		// A cache written by a release that laid its files out differently cannot be read by this one
 		if (!MetricsGenerator::isCurrent($font)) {
 			$regenerate = true;

tests/Mpdf/FontdataMetricOverrideTest.php

@@ -0,0 +1,189 @@
+<?php
+
+namespace Mpdf;
+
+/**
+ * The Ascent, Descent and Leading a fontdata entry sets replace the ones read from the font, for layout and in the
+ * FontDescriptor, without being written into the metrics cache the next document reads
+ */
+class FontdataMetricOverrideTest extends \Yoast\PHPUnitPolyfills\TestCases\TestCase
+{
+
+	use PageStreams;
+
+	/** In points */
+	const FONT_SIZE = 11;
+
+	/** What DejaVu Sans itself declares */
+	private static $fontMetrics = ['Ascent' => 928, 'Descent' => -236, 'Leading' => 0];
+
+	private static $overrides = ['Ascent' => 1500, 'Descent' => -900, 'Leading' => 400];
+
+	/** A test's documents share it, so the second one reads the cache the first one wrote */
+	private $tempDir;
+
+	/**
+	 * Give each test a cache of its own
+	 */
+	protected function set_up()
+	{
+		parent::set_up();
+
+		$this->tempDir = sys_get_temp_dir() . '/mpdf-fontdata-metric-override-' . uniqid('', true);
+	}
+
+	/**
+	 * Remove the cache the documents wrote
+	 */
+	protected function tear_down()
+	{
+		/* The directories a Cache makes, innermost first, then the tempDir itself */
+		foreach ([$this->tempDir . '/mpdf/ttfontdata', $this->tempDir . '/mpdf', $this->tempDir] as $directory) {
+			if (!is_dir($directory)) {
+				continue;
+			}
+
+			foreach (glob($directory . '/*') as $entry) {
+				if (is_file($entry)) {
+					unlink($entry);
+				}
+			}
+
+			rmdir($directory);
+		}
+
+		parent::tear_down();
+	}
+
+	/**
+	 * The registered font carries each override, and the font's own value for any metric left alone
+	 *
+	 * @dataProvider overrideProvider
+	 *
+	 * @param array $overrides
+	 */
+	public function testOverridesReplaceTheFontMetrics(array $overrides)
+	{
+		$mpdf = $this->document($overrides);
+
+		$this->assertSame(array_merge(self::$fontMetrics, $overrides), $this->metrics($mpdf->fonts['dejavusans']['desc']));
+	}
+
+	/**
+	 * Each override alone, and all three together
+	 *
+	 * @return array
+	 */
+	public function overrideProvider()
+	{
+		return [
+			'Ascent' => [['Ascent' => 1500]],
+			'Descent' => [['Descent' => -900]],
+			'Leading' => [['Leading' => 400]],
+			'all three' => [self::$overrides],
+		];
+	}
+
+	/**
+	 * A normal line is adjustFontDescLineheight times Ascent - Descent + Leading, with the Leading added again as a
+	 * line gap, so the lines of a paragraph move apart by exactly what the overrides imply
+	 */
+	public function testOverridesSetTheLineHeight()
+	{
+		$plain = $this->document([]);
+		$overridden = $this->document(self::$overrides);
+
+		$this->assertEqualsWithDelta($this->pitch(self::$fontMetrics, $plain), $this->linePitch($plain), 0.002);
+		$this->assertEqualsWithDelta($this->pitch(self::$overrides, $overridden), $this->linePitch($overridden), 0.002);
+	}
+
+	/**
+	 * The embedded font describes itself with the overridden metrics, as it did before they were lost
+	 */
+	public function testOverridesReachTheFontDescriptor()
+	{
+		$pdf = $this->output($this->document(self::$overrides));
+
+		$this->assertMatchesRegularExpression('/\/FontDescriptor\s+\/FontName \/\w+\+DejaVuSans\s+[^>]*\/Ascent 1500\s+\/Descent -900\s+\/Leading 400\s/', $pdf);
+	}
+
+	/**
+	 * A document without overrides that reads the cache a document with them wrote gets the font's own metrics
+	 */
+	public function testOverridesStayOutOfTheCache()
+	{
+		$this->output($this->document(self::$overrides));
+
+		$cached = json_decode(file_get_contents($this->tempDir . '/mpdf/ttfontdata/dejavusans.mtx.json'), true);
+		$this->assertSame(self::$fontMetrics, $this->metrics($cached['desc']));
+
+		$plain = $this->document([]);
+		$this->assertSame(self::$fontMetrics, $this->metrics($plain->fonts['dejavusans']['desc']));
+	}
+
+	/**
+	 * A document in DejaVu Sans, with $overrides on its fontdata entry, and three lines written
+	 *
+	 * @param array $overrides
+	 *
+	 * @return Mpdf
+	 */
+	private function document(array $overrides)
+	{
+		$mpdf = new Mpdf([
+			'mode' => 'utf-8',
+			'tempDir' => $this->tempDir,
+			'default_font' => 'dejavusans',
+			'default_font_size' => self::FONT_SIZE,
+			'fontdata' => ['dejavusans' => ['R' => 'DejaVuSans.ttf'] + $overrides],
+		]);
+		$mpdf->compress = false;
+		$mpdf->WriteHTML('<p>Line one<br>Line two<br>Line three</p>');
+
+		return $mpdf;
+	}
+
+	/**
+	 * @param array $desc
+	 *
+	 * @return array Ascent, Descent and Leading from a font's desc, in that order
+	 */
+	private function metrics(array $desc)
+	{
+		return [
+			'Ascent' => $desc['Ascent'],
+			'Descent' => $desc['Descent'],
+			'Leading' => $desc['Leading'],
+		];
+	}
+
+	/**
+	 * @param array $metrics
+	 * @param Mpdf $mpdf
+	 *
+	 * @return float The distance between baselines, in points, that a normal line height gives these metrics
+	 */
+	private function pitch(array $metrics, Mpdf $mpdf)
+	{
+		$lineHeight = $mpdf->adjustFontDescLineheight * ($metrics['Ascent'] - $metrics['Descent'] + $metrics['Leading']) / 1000;
+
+		return ($lineHeight + $metrics['Leading'] / 1000) * self::FONT_SIZE;
+	}
+
+	/**
+	 * @param Mpdf $mpdf
+	 *
+	 * @return float The distance between baselines, in points, of the three lines drawn, which must be even
+	 */
+	private function linePitch(Mpdf $mpdf)
+	{
+		preg_match_all('/BT [\d.]+ ([\d.]+) Td/', $this->output($mpdf), $matches);
+		$baselines = array_map('floatval', $matches[1]);
+
+		$this->assertCount(3, $baselines);
+		$this->assertEqualsWithDelta($baselines[0] - $baselines[1], $baselines[1] - $baselines[2], 0.002);
+
+		return $baselines[0] - $baselines[1];
+	}
+
+}

tests/Mpdf/TtcFontIdTest.php

@@ -0,0 +1,144 @@
+<?php
+
+namespace Mpdf;
+
+use Mpdf\Fonts\BlobReader;
+use Mpdf\Fonts\TableWriter;
+
+/**
+ * The TTCfontID a fontdata entry sets picks which font of a TrueType Collection is registered and embedded
+ */
+class TtcFontIdTest extends \Yoast\PHPUnitPolyfills\TestCases\TestCase
+{
+
+	use PageStreams;
+
+	/** Holds the collection and the cache the documents write */
+	private $tempDir;
+
+	/**
+	 * Pack two of the fixture fonts into a collection, in a directory of its own
+	 */
+	protected function set_up()
+	{
+		parent::set_up();
+
+		$this->tempDir = sys_get_temp_dir() . '/mpdf-ttc-font-id-' . uniqid('', true);
+		mkdir($this->tempDir);
+
+		$fixtures = __DIR__ . '/../data/ttf/';
+		file_put_contents($this->tempDir . '/Pair.ttc', $this->collection([
+			file_get_contents($fixtures . 'NotoSans-GPOS3-Synthetic.ttf'),
+			file_get_contents($fixtures . 'Carlito-MarkAttachmentType-Subset.ttf'),
+		]));
+	}
+
+	/**
+	 * Remove the collection and the cache
+	 */
+	protected function tear_down()
+	{
+		$files = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($this->tempDir, \FilesystemIterator::SKIP_DOTS), \RecursiveIteratorIterator::CHILD_FIRST);
+		foreach ($files as $file) {
+			$file->isDir() ? rmdir($file->getPathname()) : unlink($file->getPathname());
+		}
+		rmdir($this->tempDir);
+
+		parent::tear_down();
+	}
+
+	/**
+	 * The face registered, and the one embedded, is the one TTCfontID names
+	 *
+	 * @dataProvider faceProvider
+	 *
+	 * @param int $TTCfontID
+	 * @param string $name The PostScript name of that face
+	 */
+	public function testTheConfiguredFaceIsTheOneUsed($TTCfontID, $name)
+	{
+		$this->assertFace($TTCfontID, $name);
+	}
+
+	/**
+	 * Each face of the collection, with its PostScript name
+	 *
+	 * @return array
+	 */
+	public function faceProvider()
+	{
+		return [
+			'the first face' => [1, 'NotoSans-Regular'],
+			'the second face' => [2, 'Carlito-Regular'],
+		];
+	}
+
+	/**
+	 * Metrics cached for one face are not reused for another, which is also what catches a cache written while every
+	 * configured TTCfontID was read as the first face
+	 */
+	public function testTheCacheOfAnotherFaceIsNotReused()
+	{
+		$this->assertFace(1, 'NotoSans-Regular');
+		$this->assertFace(2, 'Carlito-Regular');
+	}
+
+	/**
+	 * Render a document in the collection's face $TTCfontID and assert it is the face named $name
+	 *
+	 * @param int $TTCfontID
+	 * @param string $name
+	 */
+	private function assertFace($TTCfontID, $name)
+	{
+		$mpdf = new Mpdf([
+			'mode' => 'utf-8',
+			'tempDir' => $this->tempDir,
+			'fontDir' => [$this->tempDir],
+			'default_font' => 'pair',
+			'fontdata' => ['pair' => ['R' => 'Pair.ttc', 'TTCfontID' => ['R' => $TTCfontID]]],
+		]);
+		$mpdf->compress = false;
+		$mpdf->WriteHTML('<p>abc</p>');
+
+		$this->assertSame($TTCfontID, $mpdf->fonts['pair']['TTCfontID']);
+		$this->assertSame($name, $mpdf->fonts['pair']['name']);
+		$this->assertMatchesRegularExpression('/\/FontDescriptor\s+\/FontName \/[A-Z]{6}\+' . $name . '\s/', $this->output($mpdf));
+	}
+
+	/**
+	 * A TrueType Collection of $fonts, each whole font copied in with its table offsets moved to where it now starts.
+	 * Nothing is shared between them, which the format allows but does not require.
+	 *
+	 * @param string[] $fonts
+	 *
+	 * @return string
+	 */
+	private function collection(array $fonts)
+	{
+		$header = 'ttcf' . TableWriter::uint32(0x00010000) . TableWriter::uint32(count($fonts));
+		$start = strlen($header) + 4 * count($fonts);
+		$body = '';
+
+		foreach ($fonts as $font) {
+			$header .= TableWriter::uint32($start);
+
+			$reader = new BlobReader($font);
+			$reader->seek(4);
+			$numTables = $reader->readUInt16();
+
+			for ($i = 0; $i < $numTables; $i++) {
+				$record = 12 + 16 * $i + 8;
+				$reader->seek($record);
+				$font = TableWriter::replace($font, $record, TableWriter::uint32($reader->readUInt32() + $start));
+			}
+
+			$font .= str_repeat("\0", (4 - strlen($font) % 4) % 4);
+			$body .= $font;
+			$start += strlen($font);
+		}
+
+		return $header . $body;
+	}
+
+}