Serve png mode from mathoid

* Use the exactly same routines to deliver png images that are used in
  mathml mode.
* Change the output to use mathoids png image rather than the mathml
  and svg output.
* Locally tested on Firefox and Chrome: Depending on the mode either
  the SVG or the PNG path is used.

Bug: T74240
Change-Id: I4b1cac92eb9a02190f316faab6621940951603d5

extension.json

@@ -31,7 +31,8 @@
 		"MathValidator": "src/MathValidator.php",
 		"MathFormatter": "src/MathFormatter.php",
 		"MathWikidataHook": "src/MathWikidataHook.php",
-		"MathMLRdfBuilder": "src/MathMLRdfBuilder.php"
+		"MathMLRdfBuilder": "src/MathMLRdfBuilder.php",
+		"MathPng": "src/MathPng.php"
 	},
 	"DefaultUserOptions": {
 		"math": "mathml"

maintenance/MathGenerateTests.php

@@ -78,8 +78,12 @@ class MathGenerateTests extends Maintenance {
 		$i = 0;
 		foreach ( array_slice( $allEquations, $offset, $length, true ) as $input ) {
 			$output = MathRenderer::renderMath( $input[1], $input[2], 'png' );
-			$output = preg_replace( '#src="(.*?)/(([a-f]|\d)*).png"#', 'src="\2.png"', $output );
+			$output = preg_replace( '#src="(.*?)/(([a-f]|\d)*)"#', 'src="\2"', $output );
-			$parserTests[] = [ (string)$input[1], $output ];
+			$parserTests[] = [
+				'input' => (string)$input[1],
+				'params' => $input[2],
+				'output' => $output
+			];
 			$i++;
 			echo '.';
 		}

src/MathMathML.php

@@ -15,6 +15,7 @@ class MathMathML extends MathRenderer {
 
 	protected $defaultAllowedRootElements = [ 'math' ];
 	protected $restbaseInputTypes = [ 'tex', 'inline-tex', 'chem' ];
+	protected $restbaseRenderingModes = [ 'mathml', 'png' ];
 	protected $allowedRootElements = [];
 	protected $hosts;
 
@@ -26,6 +27,9 @@ class MathMathML extends MathRenderer {
 	 */
 	private $svgPath = false;
 
+	/** @var string|bool */
+	private $pngPath = false;
+
 	private $mathoidStyle;
 
 	public function __construct( $tex = '', $params = [] ) {
@@ -104,7 +108,7 @@ class MathMathML extends MathRenderer {
 				$this->setPurge( true );
 			}
 			if ( in_array( $this->inputType, $this->restbaseInputTypes ) &&
-				$this->mode == 'mathml'
+				 in_array( $this->mode, $this->restbaseRenderingModes )
 			) {
 				if ( !$this->rbi ) {
 					$this->rbi =
@@ -116,6 +120,7 @@ class MathMathML extends MathRenderer {
 					$this->mathml = $rbi->getMathML();
 					$this->mathoidStyle = $rbi->getMathoidStyle();
 					$this->svgPath = $rbi->getFullSvgUrl();
+					$this->pngPath = $rbi->getFullPngUrl();
 				} elseif ( $this->lastError === '' ) {
 					$this->doCheck();
 				}
@@ -351,6 +356,9 @@ class MathMathML extends MathRenderer {
 	 * @return Title|string
 	 */
 	private function getFallbackImageUrl( $noRender = false ) {
+		if ( 'png' === $this->getMode() && $this->pngPath ) {
+			return $this->pngPath;
+		}
 		if ( $this->svgPath ) {
 			return $this->svgPath;
 		}
@@ -399,7 +407,7 @@ class MathMathML extends MathRenderer {
 	 * is false the class name will be calculated by getClassName
 	 * @return string XML the image html tag
 	 */
-	private function getFallbackImage( $noRender = false, $classOverride = false ) {
+	protected function getFallbackImage( $noRender = false, $classOverride = false ) {
 		$attribs = [
 			'src' => $this->getFallbackImageUrl( $noRender )
 		];

src/MathPng.php

@@ -0,0 +1,19 @@
+<?php
+/**
+ * MediaWiki math extension
+ *
+ * @copyright 2002-2018 various MediaWiki contributors
+ * @license GPL-2.0-or-later
+ */
+
+class MathPng extends MathMathML {
+	public function __construct( $tex = '', array $params = [] ) {
+		parent::__construct( $tex, $params );
+		$this->setMode( 'png' );
+	}
+
+	public function getHtmlOutput() {
+		return $this->getFallbackImage();
+	}
+
+}

src/MathRenderer.php

@@ -167,7 +167,7 @@ abstract class MathRenderer {
 				$renderer = new MathSource( $tex, $params );
 				break;
 			case 'png':
-				$renderer = new MathTexvc( $tex, $params );
+				$renderer = new MathPng( $tex, $params );
 				break;
 			case 'latexml':
 				$renderer = new MathLaTeXML( $tex, $params );

src/MathRestbaseInterface.php

@@ -293,6 +293,16 @@ class MathRestbaseInterface {
 		return $this->getUrl( "media/math/render/svg/{$this->hash}", false );
 	}
 
+	/**
+	 * Gets a publicly accessible link to the generated SVG image.
+	 * @return string
+	 * @throws MWException
+	 */
+	public function getFullPngUrl() {
+		$this->calculateHash();
+		return $this->getUrl( "media/math/render/png/{$this->hash}", false );
+	}
+
 	/**
 	 * @return string
 	 */

tests/MathMathMLTest.php

@@ -125,7 +125,7 @@ class MathMathMLTest extends MediaWikiTestCase {
 		$t = new Title( "test" );
 		$res = $p->parse( '[[test|<math forcemathmode="png">a+b</math>]]', $t, $po )->getText();
 		$this->assertContains( '</a>', $res );
-		$this->assertContains( '.png', $res );
+		$this->assertContains( 'png', $res );
 	}
 
 	/**

tests/phpunit/MathCoverageTest.php

@@ -24,74 +24,36 @@
  * @license GPL-2.0-or-later
  */
 class MathCoverageTest extends MediaWikiTestCase {
-	protected static $hasTexvc;
-	protected static $texvcPath;
-
-	public static function setUpBeforeClass() {
-		global $wgTexvc;
-
-		if ( is_executable( $wgTexvc ) ) {
-			wfDebugLog( __CLASS__, " using build in texvc from "
-				. "\$wgMathTexvcCheckExecutable = $wgTexvc" );
-			# Using build-in
-			self::$hasTexvc = true;
-			self::$texvcPath = $wgTexvc;
-		} else {
-			# Attempt to compile
-			wfDebugLog( __CLASS__, " compiling texvc..." );
-			$cmd = 'cd ' . dirname( __DIR__ ) . '/math; make --always-make 2>&1';
-			wfShellExec( $cmd, $retval );
-			if ( $retval === 0 ) {
-				self::$hasTexvc = true;
-				self::$texvcPath = dirname( __DIR__ ) . '/math/texvc';
-				wfDebugLog( __CLASS__, ' compiled texvc at ' . self::$texvcPath );
-			} else {
-				wfDebugLog( __CLASS__, ' ocaml not available or compilation of texvc failed' );
-			}
-		}
-	}
-
-	/**
-	 * Sets up the fixture, for example, opens a network connection.
-	 * This method is called before a test is executed.
-	 */
-	protected function setUp() {
-		parent::setUp();
-
-		if ( ! self::$hasTexvc ) {
-			$this->markTestSkipped( "No texvc installed on server" );
-		} else {
-			$this->setMwGlobals( 'wgTexvc',
-				self::$texvcPath );
-		}
-	}
 
 	/**
 	 * Loops over all test cases provided by the provider function.
 	 * Compares each the rendering result of each input with the expected output.
 	 * @dataProvider provideCoverage
 	 */
-	public function testCoverage( $input, $output ) {
+	public function testCoverage( $input, $options, $output ) {
 		// TODO: Make rendering mode configurable
 		// TODO: Provide test-ids
 		// TODO: Link to the wikipage that contains the reference rendering
 		$this->assertEquals(
 			$this->normalize( $output ),
-			$this->normalize( MathRenderer::renderMath( $input, [], 'png' ) ),
+			$this->normalize( MathRenderer::renderMath( $input, $options, 'png' ) ),
-			"Failed to render $input"
+			"Failed to render ${input}"
 		);
 	}
 
 	/**
 	 * Gets the test-data from the file ParserTest.json
-	 * @return string[] [ $input, $output ] where $input is the test input string
+	 * @return array where $input is the test input string
 	 * and $output is the rendered html5-output string
 	 */
 	public function provideCoverage() {
-		return json_decode( file_get_contents( __DIR__ . '/ParserTest.json' ) );
+		$testcases = json_decode( file_get_contents( __DIR__ . '/../ParserTest.json' ), true );
+		// uncomment for fast testing
+		// $testcases = array_slice($testcases,0,3);
+		return $testcases;
 	}
 
 	private function normalize( $input ) {
-		return preg_replace( '#src="(.*?)/(([a-f]|\d)*).png"#', 'src="\2.png"', $input );
+		return preg_replace( '#src="(.*?)/(([a-f]|\d)*)"#', 'src="\2"', $input );
 	}
 }