From 43e4292ec97415d0bcef62522f3abc3b951fa7d2 Mon Sep 17 00:00:00 2001
From: Tom Payne <twpayne@gmail.com>
Date: Fri, 6 Dec 2013 18:11:01 +0100
Subject: [PATCH] Tidy up ol.source.MapGuide and add ratio option

---
 examples/mapguide-untiled.js    |  1 +
 src/objectliterals.jsdoc        | 14 ++++--
 src/ol/source/mapguidesource.js | 81 +++++++++++++++++++--------------
 3 files changed, 57 insertions(+), 39 deletions(-)

diff --git a/examples/mapguide-untiled.js b/examples/mapguide-untiled.js
index b4d3358351..d8b84060c1 100644
--- a/examples/mapguide-untiled.js
+++ b/examples/mapguide-untiled.js
@@ -25,6 +25,7 @@ var map = new ol.Map({
           MAPDEFINITION: mdf,
           FORMAT: 'PNG'
         },
+        ratio: 2,
         extent: bounds
       })
     })
diff --git a/src/objectliterals.jsdoc b/src/objectliterals.jsdoc
index eea253f924..0e97a4467d 100644
--- a/src/objectliterals.jsdoc
+++ b/src/objectliterals.jsdoc
@@ -608,14 +608,18 @@
 
 /**
  * @typedef {Object} ol.source.MapGuideOptions
- * @property {string} url The mapagent url
- * @property {number} metersPerUnit The meters-per-unit value
- * @property {ol.Extent|undefined} extent Extent.
- * @property {boolean} useOverlay If true, will use GETDYNAMICMAPOVERLAYIMAGE
+ * @property {string|undefined} url The mapagent url.
+ * @property {number|undefined} metersPerUnit The meters-per-unit value.
+ * @property {ol.Extent|undefined} extent Extent..
+ * @property {boolean|undefined} useOverlay If true, will use
+ *     GETDYNAMICMAPOVERLAYIMAGE.
  * @property {ol.proj.ProjectionLike} projection Projection.
+ * @property {number|undefined} ratio Ratio. 1 means image requests are the size
+ *     of the map viewport, 2 means twice the size of the map viewport, and so
+ *     on.
  * @property {Array.<number>|undefined} resolutions Resolutions. If specified,
  *     requests will be made for these resolutions only.
- * @property {Object} params additional parameters
+ * @property {Object|undefined} params Additional parameters.
  */
 
 /**
diff --git a/src/ol/source/mapguidesource.js b/src/ol/source/mapguidesource.js
index 7fa5a742ed..974c69b1bc 100644
--- a/src/ol/source/mapguidesource.js
+++ b/src/ol/source/mapguidesource.js
@@ -14,30 +14,15 @@ goog.require('ol.source.Image');
  * @param {ol.source.MapGuideOptions} options Options.
  */
 ol.source.MapGuide = function(options) {
-  var imageUrlFunction = goog.isDef(options.url) ?
-      ol.ImageUrlFunction.createFromParamsFunction(
-      options.url,
-      options.params,
-      goog.bind(this.getUrl, this)) :
-      ol.ImageUrlFunction.nullImageUrlFunction;
 
-  /**
-   * @private
-   * @type {number}
-   */
-  this.metersPerUnit_ = options.metersPerUnit;
-
-  /**
-   * @private
-   * @type {boolean}
-   */
-  this.useOverlay_ = options.useOverlay;
-
-  /**
-   * @private
-   * @type {ol.Image}
-   */
-  this.image_ = null;
+  var imageUrlFunction;
+  if (goog.isDef(options.url)) {
+    var params = goog.isDef(options.params) ? options.params : {};
+    imageUrlFunction = ol.ImageUrlFunction.createFromParamsFunction(
+        options.url, params, goog.bind(this.getUrl, this));
+  } else {
+    imageUrlFunction = ol.ImageUrlFunction.nullImageUrlFunction;
+  }
 
   goog.base(this, {
     extent: options.extent,
@@ -45,6 +30,33 @@ ol.source.MapGuide = function(options) {
     resolutions: options.resolutions,
     imageUrlFunction: imageUrlFunction
   });
+
+  /**
+   * @private
+   * @type {number}
+   */
+  this.metersPerUnit_ = goog.isDef(options.metersPerUnit) ?
+      options.metersPerUnit : 1;
+
+  /**
+   * @private
+   * @type {number}
+   */
+  this.ratio_ = goog.isDef(options.ratio) ? options.ratio : 1;
+
+  /**
+   * @private
+   * @type {boolean}
+   */
+  this.useOverlay_ = goog.isDef(options.useOverlay) ?
+      options.useOverlay : false;
+
+  /**
+   * @private
+   * @type {ol.Image}
+   */
+  this.image_ = null;
+
 };
 goog.inherits(ol.source.MapGuide, ol.source.Image);
 
@@ -63,8 +75,10 @@ ol.source.MapGuide.prototype.getImage =
     return image;
   }
 
-  extent = extent.slice();
-  ol.extent.scaleFromCenter(extent, 1.0); //this.ratio_);
+  if (this.ratio_ != 1) {
+    extent = extent.slice();
+    ol.extent.scaleFromCenter(extent, this.ratio_);
+  }
   var width = (extent[2] - extent[0]) / resolution;
   var height = (extent[3] - extent[1]) / resolution;
   var size = [width, height];
@@ -75,9 +89,9 @@ ol.source.MapGuide.prototype.getImage =
 
 
 /**
- * @param {ol.Extent} extent The map extents
- * @param {ol.Size} size the viewport size
- * @return {number} The computed map scale
+ * @param {ol.Extent} extent The map extents.
+ * @param {ol.Size} size the viewport size.
+ * @return {number} The computed map scale.
  */
 ol.source.MapGuide.prototype.getScale = function(extent, size) {
   var mcsW = extent[2] - extent[0];
@@ -87,12 +101,11 @@ ol.source.MapGuide.prototype.getScale = function(extent, size) {
   var dpi = 96;
   var mpu = this.metersPerUnit_;
   var mpp = 0.0254 / dpi;
-  var scale = 0.0;
-  if (devH * mcsW > devW * mcsH)
-    scale = mcsW * mpu / (devW * mpp); //width-limited
-  else
-    scale = mcsH * mpu / (devH * mpp); //height-limited
-  return scale;
+  if (devH * mcsW > devW * mcsH) {
+    return mcsW * mpu / (devW * mpp); // width limited
+  } else {
+    return mcsH * mpu / (devH * mpp); // height limited
+  }
 };