Add WebGL support test.

launch.coffee

@@ -47,13 +47,30 @@ for a in s
     e = $ "s-#{a[0]}"
     (f = -> e.innerHTML = a[4]+a[1][a[3]])()
     e.onclick = -> f(a[3] = (a[3]+1)%a[1].length)
-$('start').onclick = ->
-  $('step-1').style.display = 'none'
-  $('step-2').style.display = 'block'
-  $('step-2').style.backgroundImage = "url(css/help-#{s[0][3]}.png)"
 $('step-2').onclick = ->
   $('step-2').style.display = 'none'
   $('step-3').style.display = 'block'
   init s[0][3], s[1][3], s[2][3], s[3][3]
 $('step-5').onclick = ->
   window.location.reload()
+
+hasWebGL = ->
+  gl = null
+  canvas = document.createElement('canvas');
+  try
+    gl = canvas.getContext("webgl")
+  if not gl?
+    try
+      gl = canvas.getContext("experimental-webgl")
+  return gl?
+
+if not hasWebGL()
+  getWebGL = $('start')
+  getWebGL.innerHTML = 'WebGL is not supported!'
+  getWebGL.onclick = ->
+    window.location.href = 'http://get.webgl.org/'
+else
+  $('start').onclick = ->
+    $('step-1').style.display = 'none'
+    $('step-2').style.display = 'block'
+    $('step-2').style.backgroundImage = "url(css/help-#{s[0][3]}.png)"

launch.js

@@ -1,6 +1,6 @@
 // Generated by CoffeeScript 1.6.3
 (function() {
-  var $, a, init, s, u, _fn, _i, _len;
+  var $, a, getWebGL, hasWebGL, init, s, u, _fn, _i, _len;
 
   $ = function(_) {
     return document.getElementById(_);
@@ -64,12 +64,6 @@
     _fn(a);
   }
 
-  $('start').onclick = function() {
-    $('step-1').style.display = 'none';
-    $('step-2').style.display = 'block';
-    return $('step-2').style.backgroundImage = "url(css/help-" + s[0][3] + ".png)";
-  };
-
   $('step-2').onclick = function() {
     $('step-2').style.display = 'none';
     $('step-3').style.display = 'block';
@@ -80,4 +74,33 @@
     return window.location.reload();
   };
 
+  hasWebGL = function() {
+    var canvas, gl;
+    gl = null;
+    canvas = document.createElement('canvas');
+    try {
+      gl = canvas.getContext("webgl");
+    } catch (_error) {}
+    if (gl == null) {
+      try {
+        gl = canvas.getContext("experimental-webgl");
+      } catch (_error) {}
+    }
+    return gl != null;
+  };
+
+  if (!hasWebGL()) {
+    getWebGL = $('start');
+    getWebGL.innerHTML = 'WebGL is not supported!';
+    getWebGL.onclick = function() {
+      return window.location.href = 'http://get.webgl.org/';
+    };
+  } else {
+    $('start').onclick = function() {
+      $('step-1').style.display = 'none';
+      $('step-2').style.display = 'block';
+      return $('step-2').style.backgroundImage = "url(css/help-" + s[0][3] + ".png)";
+    };
+  }
+
 }).call(this);