From 001400908d3d27fc33ea9cb5c4004675d67c2588 Mon Sep 17 00:00:00 2001
From: Ryan Huffman <ryanhuffman@gmail.com>
Date: Fri, 23 Oct 2015 13:37:49 -0700
Subject: [PATCH] Add automatic CCD activation to the physics engine

---
 libraries/physics/src/ObjectMotionState.cpp | 18 ++++++++++++++++++
 libraries/physics/src/ObjectMotionState.h   |  1 +
 2 files changed, 19 insertions(+)

diff --git a/libraries/physics/src/ObjectMotionState.cpp b/libraries/physics/src/ObjectMotionState.cpp
index 4f3d0396c6..b47c870216 100644
--- a/libraries/physics/src/ObjectMotionState.cpp
+++ b/libraries/physics/src/ObjectMotionState.cpp
@@ -115,6 +115,21 @@ void ObjectMotionState::setMotionType(MotionType motionType) {
     _motionType = motionType;
 }
 
+void ObjectMotionState::updateCCDConfiguration() {
+    if (_body) {
+        if (_shape) {
+            btVector3 center;
+            btScalar radius;
+            _shape->getBoundingSphere(center, radius);
+            _body->setCcdMotionThreshold(radius * 2.0f);
+            _body->setCcdSweptSphereRadius(radius);
+        } else {
+            // Disable CCD
+            _body->setCcdMotionThreshold(0);
+        }
+    }
+}
+
 void ObjectMotionState::setRigidBody(btRigidBody* body) {
     // give the body a (void*) back-pointer to this ObjectMotionState
     if (_body != body) {
@@ -125,6 +140,7 @@ void ObjectMotionState::setRigidBody(btRigidBody* body) {
         if (_body) {
             _body->setUserPointer(this);
         }
+        updateCCDConfiguration();
     }
 }
 
@@ -187,6 +203,8 @@ bool ObjectMotionState::handleHardAndEasyChanges(uint32_t flags, PhysicsEngine*
         if (_shape != newShape) {
             _shape = newShape;
             _body->setCollisionShape(_shape);
+
+            updateCCDConfiguration();
         } else {
             // huh... the shape didn't actually change, so we clear the DIRTY_SHAPE flag
             flags &= ~Simulation::DIRTY_SHAPE;
diff --git a/libraries/physics/src/ObjectMotionState.h b/libraries/physics/src/ObjectMotionState.h
index 450ac34a90..9945d07c33 100644
--- a/libraries/physics/src/ObjectMotionState.h
+++ b/libraries/physics/src/ObjectMotionState.h
@@ -137,6 +137,7 @@ protected:
     virtual bool isReadyToComputeShape() = 0;
     virtual btCollisionShape* computeNewShape() = 0;
     void setMotionType(MotionType motionType);
+    void updateCCDConfiguration();
 
     // clearObjectBackPointer() overrrides should call the base method, then actually clear the object back pointer.
     virtual void clearObjectBackPointer() { _type = MOTIONSTATE_TYPE_INVALID; }