From 60612f6397c58782aa7cd7b99bab44d80e9564ea Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Fri, 25 Jul 2014 15:23:12 -0700
Subject: [PATCH] implement VerletPoint::integrateForward()

---
 libraries/shared/src/VerletPoint.cpp | 6 ++++++
 libraries/shared/src/VerletPoint.h   | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/libraries/shared/src/VerletPoint.cpp b/libraries/shared/src/VerletPoint.cpp
index ab0715fec1..641ac39341 100644
--- a/libraries/shared/src/VerletPoint.cpp
+++ b/libraries/shared/src/VerletPoint.cpp
@@ -11,6 +11,12 @@
 
 #include "VerletPoint.h"
 
+void VerletPoint::integrateForward() {
+    glm::vec3 oldPosition = _position;
+    _position += 0.6f * (_position - _lastPosition);
+    _lastPosition = oldPosition;
+}
+
 void VerletPoint::accumulateDelta(const glm::vec3& delta) {
     _accumulatedDelta += delta;
     ++_numDeltas;
diff --git a/libraries/shared/src/VerletPoint.h b/libraries/shared/src/VerletPoint.h
index f6f8fb6d95..076a624776 100644
--- a/libraries/shared/src/VerletPoint.h
+++ b/libraries/shared/src/VerletPoint.h
@@ -18,6 +18,8 @@ class VerletPoint {
 public:
     VerletPoint() : _position(0.0f), _lastPosition(0.0f), _mass(1.0f), _accumulatedDelta(0.0f), _numDeltas(0) {}
 
+    void initPosition(const glm::vec3& position) { _position = position; _lastPosition = position; }
+    void integrateForward();
     void accumulateDelta(const glm::vec3& delta);
     void applyAccumulatedDelta();