Merge pull request #192 from fredj/rotation

Change view.rotate params: rotation and optional anchor.

src/ol/interaction/dragrotateandzoominteraction.js

@@ -26,15 +26,15 @@ ol.interaction.DragRotateAndZoom = function(condition) {
 
   /**
    * @private
-   * @type {number}
+   * @type {number|undefined}
    */
-  this.startRatio_ = 0;
+  this.lastAngle_;
 
   /**
    * @private
-   * @type {number}
+   * @type {number|undefined}
    */
-  this.startRotation_ = 0;
+  this.lastMagnitude_;
 
 };
 goog.inherits(ol.interaction.DragRotateAndZoom, ol.interaction.Drag);
@@ -52,15 +52,23 @@ ol.interaction.DragRotateAndZoom.prototype.handleDrag =
       browserEvent.offsetX - size.width / 2,
       size.height / 2 - browserEvent.offsetY);
   var theta = Math.atan2(delta.y, delta.x);
-  var resolution = this.startRatio_ * delta.magnitude();
+  var magnitude = delta.magnitude();
   // FIXME works for View2D only
   var view = map.getView();
   goog.asserts.assert(view instanceof ol.View2D);
   map.requestRenderFrame();
   // FIXME the calls to map.rotate and map.zoomToResolution should use
   // map.withFrozenRendering but an assertion fails :-(
-  view.rotate(map, this.startRotation_, -theta);
-  view.zoomToResolution(map, resolution);
+  if (goog.isDef(this.lastAngle_)) {
+    var angleDelta = theta - this.lastAngle_;
+    view.rotate(map, view.getRotation() - angleDelta);
+  }
+  this.lastAngle_ = theta;
+  if (goog.isDef(this.lastMagnitude_)) {
+    var resolution = this.lastMagnitude_ * (view.getResolution() / magnitude);
+    view.zoomToResolution(map, resolution);
+  }
+  this.lastMagnitude_ = magnitude;
 };
 
 
@@ -70,18 +78,9 @@ ol.interaction.DragRotateAndZoom.prototype.handleDrag =
 ol.interaction.DragRotateAndZoom.prototype.handleDragStart =
     function(mapBrowserEvent) {
   var browserEvent = mapBrowserEvent.browserEvent;
-  var map = mapBrowserEvent.map;
-  var view = map.getView().getView2D();
   if (this.condition_(browserEvent)) {
-    var resolution = view.getResolution();
-    var size = map.getSize();
-    var delta = new goog.math.Vec2(
-        browserEvent.offsetX - size.width / 2,
-        size.height / 2 - browserEvent.offsetY);
-    var theta = Math.atan2(delta.y, delta.x);
-    this.startRotation_ = view.getRotation() + theta;
-    this.startRatio_ = resolution / delta.magnitude();
-    map.requestRenderFrame();
+    this.lastAngle_ = undefined;
+    this.lastMagnitude_ = undefined;
     return true;
   } else {
     return false;

src/ol/interaction/dragrotateinteraction.js

@@ -23,9 +23,9 @@ ol.interaction.DragRotate = function(condition) {
 
   /**
    * @private
-   * @type {number}
+   * @type {number|undefined}
    */
-  this.startRotation_ = 0;
+  this.lastAngle_;
 
 };
 goog.inherits(ol.interaction.DragRotate, ol.interaction.Drag);
@@ -39,14 +39,16 @@ ol.interaction.DragRotate.prototype.handleDrag = function(mapBrowserEvent) {
   var map = mapBrowserEvent.map;
   var size = map.getSize();
   var offset = mapBrowserEvent.getPixel();
-  var theta = Math.atan2(
-      size.height / 2 - offset.y,
-      offset.x - size.width / 2);
-  // FIXME supports View2D only
-  var view = map.getView();
-  goog.asserts.assert(view instanceof ol.View2D);
-  map.requestRenderFrame();
-  view.rotate(map, this.startRotation_, -theta);
+  var theta = Math.atan2(size.height / 2 - offset.y, offset.x - size.width / 2);
+  if (goog.isDef(this.lastAngle_)) {
+    var delta = theta - this.lastAngle_;
+    var view = map.getView();
+    // FIXME supports View2D only
+    goog.asserts.assert(view instanceof ol.View2D);
+    map.requestRenderFrame();
+    view.rotate(map, view.getRotation() - delta);
+  }
+  this.lastAngle_ = theta;
 };
 
 
@@ -56,18 +58,13 @@ ol.interaction.DragRotate.prototype.handleDrag = function(mapBrowserEvent) {
 ol.interaction.DragRotate.prototype.handleDragStart =
     function(mapBrowserEvent) {
   var browserEvent = mapBrowserEvent.browserEvent;
-  var map = mapBrowserEvent.map;
-  // FIXME supports View2D only
-  var view = map.getView();
-  goog.asserts.assert(view instanceof ol.View2D);
   if (browserEvent.isMouseActionButton() && this.condition_(browserEvent)) {
+    var map = mapBrowserEvent.map;
+    // FIXME supports View2D only
+    var view = map.getView();
+    goog.asserts.assert(view instanceof ol.View2D);
     map.requestRenderFrame();
-    var size = map.getSize();
-    var offset = mapBrowserEvent.getPixel();
-    var theta = Math.atan2(
-        size.height / 2 - offset.y,
-        offset.x - size.width / 2);
-    this.startRotation_ = view.getRotation() + theta;
+    this.lastAngle_ = undefined;
     return true;
   } else {
     return false;

src/ol/view2d.js

@@ -256,11 +256,26 @@ goog.exportProperty(
 /**
  * @param {ol.Map} map Map.
  * @param {number|undefined} rotation Rotation.
- * @param {number} delta Delta.
+ * @param {ol.Coordinate=} opt_anchor Anchor coordinate.
  */
-ol.View2D.prototype.rotate = function(map, rotation, delta) {
-  rotation = this.constraints_.rotation(rotation, delta);
-  this.setRotation(rotation);
+ol.View2D.prototype.rotate = function(map, rotation, opt_anchor) {
+  rotation = this.constraints_.rotation(rotation, 0);
+  if (goog.isDefAndNotNull(opt_anchor)) {
+    var anchor = opt_anchor;
+    var oldCenter = /** @type {!ol.Coordinate} */ (this.getCenter());
+    var center = new ol.Coordinate(
+        oldCenter.x - anchor.x,
+        oldCenter.y - anchor.y);
+    center.rotate(rotation - this.getRotation());
+    center.x += anchor.x;
+    center.y += anchor.y;
+    map.withFrozenRendering(function() {
+      this.setCenter(center);
+      this.setRotation(rotation);
+    }, this);
+  } else {
+    this.setRotation(rotation);
+  }
 };