From d6dc1a2c6fafe5f446123e197d09011c2d5dcdb1 Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Wed, 4 Dec 2013 11:58:05 +0100
Subject: [PATCH 1/2] Don't use WebGL if there is a major performance caveat

---
 src/ol/renderer/webgl/webglmaprenderer.js | 1 +
 src/ol/webgl/webgl.js                     | 4 +++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/ol/renderer/webgl/webglmaprenderer.js b/src/ol/renderer/webgl/webglmaprenderer.js
index c8d014030c..3880918334 100644
--- a/src/ol/renderer/webgl/webglmaprenderer.js
+++ b/src/ol/renderer/webgl/webglmaprenderer.js
@@ -88,6 +88,7 @@ ol.renderer.webgl.Map = function(container, map) {
   this.gl_ = ol.webgl.getContext(this.canvas_, {
     antialias: true,
     depth: false,
+    failIfMajorPerformanceCaveat: true,
     preserveDrawingBuffer: false,
     stencil: false
   });
diff --git a/src/ol/webgl/webgl.js b/src/ol/webgl/webgl.js
index 4e84847510..701ae5b6ed 100644
--- a/src/ol/webgl/webgl.js
+++ b/src/ol/webgl/webgl.js
@@ -59,7 +59,9 @@ ol.webgl.SUPPORTED = (function() {
   try {
     var canvas = /** @type {HTMLCanvasElement} */
         (goog.dom.createElement(goog.dom.TagName.CANVAS));
-    return !goog.isNull(ol.webgl.getContext(canvas));
+    return !goog.isNull(ol.webgl.getContext(canvas, {
+      failIfMajorPerformanceCaveat: true
+    }));
   } catch (e) {
     return false;
   }

From 0d3583bd8d0a43e0a19f428523f25d9bbb952de8 Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Wed, 4 Dec 2013 11:59:29 +0100
Subject: [PATCH 2/2] Improve type checking in WebGL support test

---
 src/ol/webgl/webgl.js | 32 ++++++++++++++++++--------------
 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/src/ol/webgl/webgl.js b/src/ol/webgl/webgl.js
index 701ae5b6ed..8720d354d6 100644
--- a/src/ol/webgl/webgl.js
+++ b/src/ol/webgl/webgl.js
@@ -52,17 +52,21 @@ ol.webgl.getContext = function(canvas, opt_attributes) {
  * @const
  * @type {boolean}
  */
-ol.webgl.SUPPORTED = (function() {
-  if (!('WebGLRenderingContext' in goog.global)) {
-    return false;
-  }
-  try {
-    var canvas = /** @type {HTMLCanvasElement} */
-        (goog.dom.createElement(goog.dom.TagName.CANVAS));
-    return !goog.isNull(ol.webgl.getContext(canvas, {
-      failIfMajorPerformanceCaveat: true
-    }));
-  } catch (e) {
-    return false;
-  }
-})();
+ol.webgl.SUPPORTED = (
+    /**
+     * @return {boolean} WebGL supported.
+     */
+    function() {
+      if (!('WebGLRenderingContext' in goog.global)) {
+        return false;
+      }
+      try {
+        var canvas = /** @type {HTMLCanvasElement} */
+            (goog.dom.createElement(goog.dom.TagName.CANVAS));
+        return !goog.isNull(ol.webgl.getContext(canvas, {
+          failIfMajorPerformanceCaveat: true
+        }));
+      } catch (e) {
+        return false;
+      }
+    })();