From 1ac9f2f5633070f456ac73da2f64f6cc867e2065 Mon Sep 17 00:00:00 2001
From: ZappoMan <bradh@konamoxt.com>
Date: Mon, 17 Nov 2014 14:51:46 -0800
Subject: [PATCH] first cut at movable entities script

---
 examples/entityScripts/movable.js | 80 +++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 examples/entityScripts/movable.js

diff --git a/examples/entityScripts/movable.js b/examples/entityScripts/movable.js
new file mode 100644
index 0000000000..432a0be3f0
--- /dev/null
+++ b/examples/entityScripts/movable.js
@@ -0,0 +1,80 @@
+//
+//  movable.js
+//  examples/entityScripts
+//
+//  Created by Brad Hefta-Gaub on 11/17/14.
+//  Copyright 2014 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+(function(){ 
+
+    this.entityID = null;
+    this.properties = null;
+    this.graboffset = null;
+
+    // Pr, Vr are respectively the Ray's Point of origin and Vector director
+    // Pp, Np are respectively the Plane's Point of origin and Normal vector
+    this.rayPlaneIntersection = function(Pr, Vr, Pp, Np) {
+        var d = -Vec3.dot(Pp, Np);
+        var t = -(Vec3.dot(Pr, Np) + d) / Vec3.dot(Vr, Np);
+        return Vec3.sum(Pr, Vec3.multiply(t, Vr));
+    };
+
+    // updates the piece position based on mouse input
+    this.updatePosition = function(mouseEvent) {
+        var pickRay = Camera.computePickRay(mouseEvent.x, mouseEvent.y)
+        var upVector = { x: 0, y: 1, z: 0 };
+        var intersection = this.rayPlaneIntersection(pickRay.origin, pickRay.direction,
+                                                     this.properties.position, upVector);
+                                                     
+        var newPosition = Vec3.sum(intersection, this.graboffset);
+        Entities.editEntity(this.entityID, { position: newPosition });
+    };
+
+    this.grab = function(mouseEvent) {
+        // first calculate the offset
+        var pickRay = Camera.computePickRay(mouseEvent.x, mouseEvent.y)
+        var upVector = { x: 0, y: 1, z: 0 };
+        var intersection = this.rayPlaneIntersection(pickRay.origin, pickRay.direction,
+                                                     this.properties.position, upVector);                                 
+        this.graboffset = Vec3.subtract(this.properties.position, intersection);
+        this.updatePosition(mouseEvent);
+    };
+    
+    this.move = function(mouseEvent) {
+        this.updatePosition(mouseEvent);
+    };
+    
+    this.release = function(mouseEvent) {
+        this.updatePosition(mouseEvent);
+    };
+    
+      // All callbacks start by updating the properties
+    this.updateProperties = function(entityID) {
+        if (this.entityID === null || !this.entityID.isKnownID) {
+            this.entityID = Entities.identifyEntity(entityID);
+        }
+        this.properties = Entities.getEntityProperties(this.entityID);
+    };
+  
+    this.preload = function(entityID) {
+        this.updateProperties(entityID); // All callbacks start by updating the properties
+    };
+    
+    this.clickDownOnEntity = function(entityID, mouseEvent) {
+        this.updateProperties(entityID); // All callbacks start by updating the properties
+        this.grab(mouseEvent);
+    };
+    
+    this.holdingClickOnEntity = function(entityID, mouseEvent) {
+        this.updateProperties(entityID); // All callbacks start by updating the properties
+        this.move(mouseEvent);
+    };
+    this.clickReleaseOnEntity = function(entityID, mouseEvent) {
+        this.updateProperties(entityID); // All callbacks start by updating the properties
+        this.release(mouseEvent);
+    };
+
+})