From c836c8d9c4b32cdb2ff18d211414331e2bed5cc7 Mon Sep 17 00:00:00 2001
From: Frederic Junod <frederic.junod@camptocamp.com>
Date: Mon, 21 Jan 2013 15:08:15 +0100
Subject: [PATCH 1/3] Add ol.Map.getRenderer function

---
 src/ol/map.js | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/ol/map.js b/src/ol/map.js
index 6ab92eb8b8..8c222f40df 100644
--- a/src/ol/map.js
+++ b/src/ol/map.js
@@ -345,6 +345,14 @@ goog.exportProperty(
     ol.Map.prototype.getBackgroundColor);
 
 
+/**
+ * @return {ol.renderer.Map} Renderer.
+ */
+ol.Map.prototype.getRenderer = function() {
+  return this.renderer_;
+};
+
+
 /**
  * @return {Element} Container.
  */

From 2f2ea373ca0624c978223b17f04c434f02ab79a3 Mon Sep 17 00:00:00 2001
From: Frederic Junod <frederic.junod@camptocamp.com>
Date: Mon, 21 Jan 2013 15:18:18 +0100
Subject: [PATCH 2/3] Add ol.renderer.Map.getCanvas function. Only valid with
 the canvas and webgl renderers

---
 src/ol/renderer/canvas/canvasmaprenderer.js | 8 ++++++++
 src/ol/renderer/maprenderer.js              | 6 ++++++
 src/ol/renderer/webgl/webglmaprenderer.js   | 8 ++++++++
 3 files changed, 22 insertions(+)

diff --git a/src/ol/renderer/canvas/canvasmaprenderer.js b/src/ol/renderer/canvas/canvasmaprenderer.js
index b664dc977a..4b253c41d4 100644
--- a/src/ol/renderer/canvas/canvasmaprenderer.js
+++ b/src/ol/renderer/canvas/canvasmaprenderer.js
@@ -67,6 +67,14 @@ ol.renderer.canvas.Map.prototype.createLayerRenderer = function(layer) {
 };
 
 
+/**
+ * @inheritDoc
+ */
+ol.renderer.canvas.Map.prototype.getCanvas = function() {
+  return this.canvas_;
+};
+
+
 /**
  * @inheritDoc
  */
diff --git a/src/ol/renderer/maprenderer.js b/src/ol/renderer/maprenderer.js
index 14b3db6d9f..0e8f876bb9 100644
--- a/src/ol/renderer/maprenderer.js
+++ b/src/ol/renderer/maprenderer.js
@@ -148,6 +148,12 @@ ol.renderer.Map.prototype.disposeInternal = function() {
 };
 
 
+/**
+ * @return {Element} Canvas.
+ */
+ol.renderer.Map.prototype.getCanvas = goog.functions.NULL;
+
+
 /**
  * @param {ol.layer.Layer} layer Layer.
  * @protected
diff --git a/src/ol/renderer/webgl/webglmaprenderer.js b/src/ol/renderer/webgl/webglmaprenderer.js
index c334e59b80..211c6bb25c 100644
--- a/src/ol/renderer/webgl/webglmaprenderer.js
+++ b/src/ol/renderer/webgl/webglmaprenderer.js
@@ -294,6 +294,14 @@ ol.renderer.webgl.Map.prototype.disposeInternal = function() {
 };
 
 
+/**
+ * @inheritDoc
+ */
+ol.renderer.webgl.Map.prototype.getCanvas = function() {
+  return this.canvas_;
+};
+
+
 /**
  * @return {WebGLRenderingContext} GL.
  */

From 8cbe0fbbbb4ed9c21e6c87ccd9ad1325e75ec6e0 Mon Sep 17 00:00:00 2001
From: Frederic Junod <frederic.junod@camptocamp.com>
Date: Mon, 21 Jan 2013 15:24:45 +0100
Subject: [PATCH 3/3] Export canvas map as jpeg image

---
 examples/two-layers.html | 2 +-
 examples/two-layers.js   | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/examples/two-layers.html b/examples/two-layers.html
index 4d7ac617ce..3e23234af5 100644
--- a/examples/two-layers.html
+++ b/examples/two-layers.html
@@ -21,7 +21,7 @@
       <tr>
         <th>DOM</th>
         <th>WebGL</th>
-        <th>Canvas</th>
+        <th>Canvas <a id="canvas-export" href="#" download="map.png">export map as png</a></th>
       </tr>
       <tr>
         <td><div id="domMap" class="map"></div></td>
diff --git a/examples/two-layers.js b/examples/two-layers.js
index 4817a59a15..9d8b66ec71 100644
--- a/examples/two-layers.js
+++ b/examples/two-layers.js
@@ -48,3 +48,7 @@ var canvasMap = new ol.Map({
 });
 canvasMap.bindTo('layers', webglMap);
 canvasMap.bindTo('view', webglMap);
+
+goog.events.listen(goog.dom.getElement('canvas-export'), 'click', function(e) {
+  e.target.href = canvasMap.getRenderer().getCanvas().toDataURL();
+});