Added undo button (only one level)

prototype/index.md

@@ -26,6 +26,7 @@ button.
 
 <button class="btn btn-primary" id="full" style="margin-bottom: 10px; display: none;">Fullscreen</button>
 <button class="btn btn-primary" id="reset" style="margin-bottom:10px">Reset camera</button>
+<button class="btn btn-primary" id="undo" style="margin-bottom:10px">Undo</button>
 <input  type="checkbox" id="fullarrow" style="margin-bottom:10px">
 <label  for="fullarrow">Full arrow</label>
 <input  type="checkbox" id="collisions" style="margin-bottom:10px" checked>

static/js/PointerCamera.js

@@ -247,6 +247,16 @@ PointerCamera.prototype.log = function() {
     console.log("(" + this.target.x + "," +  this.target.y + ',' + this.target.z + ')');
 }
 
+PointerCamera.prototype.save = function() {
+    this.backup = {};
+    this.backup.position = this.position.clone();
+    this.backup.target = this.target.clone();
+}
+
+PointerCamera.prototype.load = function() {
+    this.move(this.backup);
+}
+
 // Static members
 PointerCamera.DISTANCE_X = 1000;
 PointerCamera.DISTANCE_Z = 300;

static/js/prototype/main.js

@@ -65,6 +65,10 @@ function init() {
         showArrows = showarrows.checked;
     }
 
+    document.getElementById('undo').onclick = function() {
+        cameras.mainCamera().load();
+    }
+
     // on initialise le moteur de rendu
     container = document.getElementById('container');
     container.style.height = container_size.height() + 'px';
@@ -474,9 +478,11 @@ function updateMouse(event) {
 
 function click(event) {
     var newCamera = pointedCamera(event);
-    if (newCamera !== undefined)
+    if (newCamera !== undefined) {
+        cameras.mainCamera().save();
         cameras.mainCamera().move(newCamera);
     }
+}
 
 function pointedCamera(event) {
     var returnCamera;