From 113888120f9d0ba8eaba1935af365cc300f8ebbf Mon Sep 17 00:00:00 2001
From: Frederic Junod <frederic.junod@camptocamp.com>
Date: Wed, 20 Aug 2014 10:38:39 +0200
Subject: [PATCH 1/4] Use goog.math.toDegrees

---
 src/ol/control/rotatecontrol.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/ol/control/rotatecontrol.js b/src/ol/control/rotatecontrol.js
index 3de372ce91..8b64185d34 100644
--- a/src/ol/control/rotatecontrol.js
+++ b/src/ol/control/rotatecontrol.js
@@ -5,6 +5,7 @@ goog.require('goog.dom');
 goog.require('goog.dom.TagName');
 goog.require('goog.events');
 goog.require('goog.events.EventType');
+goog.require('goog.math');
 goog.require('ol.animation');
 goog.require('ol.control.Control');
 goog.require('ol.css');
@@ -146,7 +147,7 @@ ol.control.Rotate.prototype.handleMapPostrender = function(mapEvent) {
     return;
   }
   var rotation = frameState.viewState.rotation;
-  var transform = 'rotate(' + rotation * 360 / (Math.PI * 2) + 'deg)';
+  var transform = 'rotate(' + goog.math.toDegrees(rotation) + 'deg)';
   if (this.autoHide_) {
     this.element.style.opacity = (rotation === 0) ? 0 : 1;
   }

From 7c1439913386cc226f5077086162299d76285789 Mon Sep 17 00:00:00 2001
From: Frederic Junod <frederic.junod@camptocamp.com>
Date: Wed, 20 Aug 2014 10:45:39 +0200
Subject: [PATCH 2/4] Add missing jsdoc tag

---
 src/ol/control/rotatecontrol.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/ol/control/rotatecontrol.js b/src/ol/control/rotatecontrol.js
index 8b64185d34..3aba7fdd17 100644
--- a/src/ol/control/rotatecontrol.js
+++ b/src/ol/control/rotatecontrol.js
@@ -34,6 +34,11 @@ ol.control.Rotate = function(opt_options) {
   var label = goog.dom.createDom(goog.dom.TagName.SPAN,
       { 'class': 'ol-compass' },
       goog.isDef(options.label) ? options.label : '\u21E7');
+
+  /**
+   * @type {Element}
+   * @private
+   */
   this.label_ = label;
 
   var tipLabel = goog.isDef(options.tipLabel) ?

From 27ae50e67367181567adc7775a1388c394139e41 Mon Sep 17 00:00:00 2001
From: Frederic Junod <frederic.junod@camptocamp.com>
Date: Wed, 20 Aug 2014 10:53:44 +0200
Subject: [PATCH 3/4] Only update rotate control element when it's needed

To avoid a lot of 'Recalculate style' events by the browser.
---
 src/ol/control/rotatecontrol.js | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/ol/control/rotatecontrol.js b/src/ol/control/rotatecontrol.js
index 3aba7fdd17..9e4d9bf5de 100644
--- a/src/ol/control/rotatecontrol.js
+++ b/src/ol/control/rotatecontrol.js
@@ -88,6 +88,12 @@ ol.control.Rotate = function(opt_options) {
    */
   this.autoHide_ = goog.isDef(options.autoHide) ? options.autoHide : true;
 
+  /**
+   * @private
+   * @type {number|undefined}
+   */
+  this.rotation_ = undefined;
+
   element.style.opacity = (this.autoHide_) ? 0 : 1;
 
 };
@@ -152,11 +158,14 @@ ol.control.Rotate.prototype.handleMapPostrender = function(mapEvent) {
     return;
   }
   var rotation = frameState.viewState.rotation;
-  var transform = 'rotate(' + goog.math.toDegrees(rotation) + 'deg)';
-  if (this.autoHide_) {
-    this.element.style.opacity = (rotation === 0) ? 0 : 1;
+  if (rotation != this.rotation_) {
+    var transform = 'rotate(' + goog.math.toDegrees(rotation) + 'deg)';
+    if (this.autoHide_) {
+      this.element.style.opacity = (rotation === 0) ? 0 : 1;
+    }
+    this.label_.style.msTransform = transform;
+    this.label_.style.webkitTransform = transform;
+    this.label_.style.transform = transform;
   }
-  this.label_.style.msTransform = transform;
-  this.label_.style.webkitTransform = transform;
-  this.label_.style.transform = transform;
+  this.rotation_ = rotation;
 };

From 7f086e138ae39101318284a927bb66a3b579b31f Mon Sep 17 00:00:00 2001
From: Frederic Junod <frederic.junod@camptocamp.com>
Date: Wed, 20 Aug 2014 11:17:44 +0200
Subject: [PATCH 4/4] Remove unnecessary local variable

---
 src/ol/control/rotatecontrol.js | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/ol/control/rotatecontrol.js b/src/ol/control/rotatecontrol.js
index 9e4d9bf5de..0d041b8554 100644
--- a/src/ol/control/rotatecontrol.js
+++ b/src/ol/control/rotatecontrol.js
@@ -31,15 +31,13 @@ ol.control.Rotate = function(opt_options) {
   var className = goog.isDef(options.className) ?
       options.className : 'ol-rotate';
 
-  var label = goog.dom.createDom(goog.dom.TagName.SPAN,
-      { 'class': 'ol-compass' },
-      goog.isDef(options.label) ? options.label : '\u21E7');
-
   /**
    * @type {Element}
    * @private
    */
-  this.label_ = label;
+  this.label_ = goog.dom.createDom(goog.dom.TagName.SPAN,
+      { 'class': 'ol-compass' },
+      goog.isDef(options.label) ? options.label : '\u21E7');
 
   var tipLabel = goog.isDef(options.tipLabel) ?
       options.tipLabel : 'Reset rotation';
@@ -51,7 +49,7 @@ ol.control.Rotate = function(opt_options) {
     'class': className + '-reset ol-has-tooltip',
     'name' : 'ResetRotation',
     'type' : 'button'
-  }, tip, label);
+  }, tip, this.label_);
 
   var handler = new ol.pointer.PointerEventHandler(button);
   this.registerDisposable(handler);