From 3e23b8b690222d914b2d6839eabd18f6c08f0eed Mon Sep 17 00:00:00 2001
From: Hakim El Hattab <hakim.elhattab@gmail.com>
Date: Mon, 12 Aug 2013 23:15:19 -0400
Subject: [PATCH] make mathjax host a config option, revamp script loading,
 fragment examples #531

---
 examples/math.html  | 75 +++++++++++++++++++++++++++++++++++++++++++++
 plugin/math/math.js | 54 ++++++++++++++++++++------------
 2 files changed, 109 insertions(+), 20 deletions(-)

diff --git a/examples/math.html b/examples/math.html
index d282f8a..03fe22a 100644
--- a/examples/math.html
+++ b/examples/math.html
@@ -93,6 +93,79 @@
 					\]
 				</section>
 
+				<section>
+					<section>
+						<h3>The Lorenz Equations</h3>
+
+						<div class="fragment">
+							\[\begin{aligned}
+							\dot{x} &amp; = \sigma(y-x) \\
+							\dot{y} &amp; = \rho x - y - xz \\
+							\dot{z} &amp; = -\beta z + xy
+							\end{aligned} \]
+						</div>
+					</section>
+
+					<section>
+						<h3>The Cauchy-Schwarz Inequality</h3>
+
+						<div class="fragment">
+							\[ \left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right) \]
+						</div>
+					</section>
+
+					<section>
+						<h3>A Cross Product Formula</h3>
+
+						<div class="fragment">
+							\[\mathbf{V}_1 \times \mathbf{V}_2 =  \begin{vmatrix}
+							\mathbf{i} &amp; \mathbf{j} &amp; \mathbf{k} \\
+							\frac{\partial X}{\partial u} &amp;  \frac{\partial Y}{\partial u} &amp; 0 \\
+							\frac{\partial X}{\partial v} &amp;  \frac{\partial Y}{\partial v} &amp; 0
+							\end{vmatrix}  \]
+						</div>
+					</section>
+
+					<section>
+						<h3>The probability of getting \(k\) heads when flipping \(n\) coins is</h3>
+
+						<div class="fragment">
+							\[P(E)   = {n \choose k} p^k (1-p)^{ n-k} \]
+						</div>
+					</section>
+
+					<section>
+						<h3>An Identity of Ramanujan</h3>
+
+						<div class="fragment">
+							\[ \frac{1}{\Bigl(\sqrt{\phi \sqrt{5}}-\phi\Bigr) e^{\frac25 \pi}} =
+							1+\frac{e^{-2\pi}} {1+\frac{e^{-4\pi}} {1+\frac{e^{-6\pi}}
+							{1+\frac{e^{-8\pi}} {1+\ldots} } } } \]
+						</div>
+					</section>
+
+					<section>
+						<h3>A Rogers-Ramanujan Identity</h3>
+
+						<div class="fragment">
+							\[  1 +  \frac{q^2}{(1-q)}+\frac{q^6}{(1-q)(1-q^2)}+\cdots =
+							\prod_{j=0}^{\infty}\frac{1}{(1-q^{5j+2})(1-q^{5j+3})}\]
+						</div>
+					</section>
+
+					<section>
+						<h3>Maxwell&#8217;s Equations</h3>
+
+						<div class="fragment">
+							\[  \begin{aligned}
+							\nabla \times \vec{\mathbf{B}} -\, \frac1c\, \frac{\partial\vec{\mathbf{E}}}{\partial t} &amp; = \frac{4\pi}{c}\vec{\mathbf{j}} \\   \nabla \cdot \vec{\mathbf{E}} &amp; = 4 \pi \rho \\
+							\nabla \times \vec{\mathbf{E}}\, +\, \frac1c\, \frac{\partial\vec{\mathbf{B}}}{\partial t} &amp; = \vec{\mathbf{0}} \\
+							\nabla \cdot \vec{\mathbf{B}} &amp; = 0 \end{aligned}
+							\]
+						</div>
+					</section>
+				</section>
+
 			</div>
 
 		</div>
@@ -103,9 +176,11 @@
 		<script>
 
 			Reveal.initialize({
+				history: true,
 				transition: 'linear',
 
 				math: {
+					// host: 'http://cdn.mathjax.org/mathjax/latest/MathJax.js',
 					mode: 'TeX-AMS_HTML-full'
 				},
 
diff --git a/plugin/math/math.js b/plugin/math/math.js
index b6bd82f..78856a5 100755
--- a/plugin/math/math.js
+++ b/plugin/math/math.js
@@ -9,27 +9,10 @@ var RevealMath = window.RevealMath || (function(){
 	var loaded = false;
 
 	var config = Reveal.getConfig().math || {};
+	config.host = config.host || 'http://cdn.mathjax.org/mathjax/latest/MathJax.js';
 	config.mode = config.mode || 'TeX-AMS_HTML-full';
 
-	var head = document.querySelector( 'head' );
-	var script = document.createElement( 'script' );
-	script.type = 'text/javascript';
-	script.src = 'http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=' + config.mode;
-
-	// Detect when the script has loaded
-	script.onload = onScriptLoad;
-
-	// IE
-	script.onreadystatechange = function() {
-		if ( this.readyState === 'loaded' ) {
-			onScriptLoad.call();
-		}
-	}
-
-	// Normal browsers
-	head.appendChild( script );
-
-	function onScriptLoad() {
+	loadScript( config.host + '?config=' + config.mode, function() {
 
 		// Conditioned just in case both onload and readystate fire
 		if( loaded === false ) {
@@ -48,11 +31,42 @@ var RevealMath = window.RevealMath || (function(){
 				// This will only typeset equations that have not yet been
 				// processed, as well as equations that have change since
 				// last being processed.
-				MathJax.Hub.Update( event.currentSlide );
+				MathJax.Hub.Update( event.currentSlide, function() {
+					Reveal.layout();
+				} );
 
 			} );
 		}
 
+	} );
+
+	function loadScript( url, callback ) {
+
+		var head = document.querySelector( 'head' );
+		var script = document.createElement( 'script' );
+		script.type = 'text/javascript';
+		script.src = url;
+
+		// Wrapper for callback to make sure it only fires once
+		var finish = function() {
+			if( typeof callback === 'function' ) {
+				callback.call();
+				callback = null;
+			}
+		}
+
+		script.onload = finish;
+
+		// IE
+		script.onreadystatechange = function() {
+			if ( this.readyState === 'loaded' ) {
+				finish.call();
+			}
+		}
+
+		// Normal browsers
+		head.appendChild( script );
+
 	}
 
 })();