From adc53c65239e58cc413a59c7890f1c1fcc239021 Mon Sep 17 00:00:00 2001
From: Daniel Chappuis <chappuis.daniel@gmail.com>
Date: Sun, 9 Nov 2014 18:53:50 +0100
Subject: [PATCH] Make possible to use the CollisionBody::setIsActive() method
 to activate or deactivate the simulation of a given body

---
 src/body/Body.h            | 18 ++++++++++++++++--
 src/body/CollisionBody.cpp | 38 ++++++++++++++++++++++++++++++++++++++
 src/body/CollisionBody.h   |  3 +++
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/src/body/Body.h b/src/body/Body.h
index 2a0077a1..a4dc54f6 100644
--- a/src/body/Body.h
+++ b/src/body/Body.h
@@ -54,8 +54,14 @@ class Body {
         /// True if the body is allowed to go to sleep for better efficiency
         bool mIsAllowedToSleep;
 
-        // TODO : Use this variable to make bodies active or not
-        /// True if the body is active
+        /// True if the body is active.
+        /// An inactive body does not participate in collision detection,
+        /// is not simulated and will not be hit in a ray casting query.
+        /// A body is active by default. If you set this
+        /// value to "false", all the proxy shapes of this body will be
+        /// removed from the broad-phase. If you set this value to "true",
+        /// all the proxy shapes will be added to the broad-phase. A joint
+        /// connected to an inactive body will also be inactive.
         bool mIsActive;
 
         /// True if the body is sleeping (for sleeping technique)
@@ -100,6 +106,9 @@ class Body {
         /// Return true if the body is active
         bool isActive() const;
 
+        /// Set whether or not the body is active
+        virtual void setIsActive(bool isActive);
+
         /// Set the variable to know whether or not the body is sleeping
         virtual void setIsSleeping(bool isSleeping);
 
@@ -153,6 +162,11 @@ inline bool Body::isActive() const {
     return mIsActive;
 }
 
+// Set whether or not the body is active
+inline void Body::setIsActive(bool isActive) {
+    mIsActive = isActive;
+}
+
 // Set the variable to know whether or not the body is sleeping
 inline void Body::setIsSleeping(bool isSleeping) {
 
diff --git a/src/body/CollisionBody.cpp b/src/body/CollisionBody.cpp
index 921268ef..e8108bb9 100644
--- a/src/body/CollisionBody.cpp
+++ b/src/body/CollisionBody.cpp
@@ -188,6 +188,44 @@ void CollisionBody::updateBroadPhaseState() const {
     }
 }
 
+// Set whether or not the body is active
+void CollisionBody::setIsActive(bool isActive) {
+
+    // If the state does not change
+    if (mIsActive == isActive) return;
+
+    Body::setIsActive(isActive);
+
+    // TODO : Implement this
+
+    // If we have to activate the body
+    if (isActive) {
+
+        // For each proxy shape of the body
+        for (ProxyShape* shape = mProxyCollisionShapes; shape != NULL; shape = shape->mNext) {
+
+            // Compute the world-space AABB of the new collision shape
+            AABB aabb;
+            shape->getCollisionShape()->computeAABB(aabb, mTransform * shape->mLocalToBodyTransform);
+
+            // Add the proxy shape to the collision detection
+            mWorld.mCollisionDetection.addProxyCollisionShape(shape, aabb);
+        }
+    }
+    else {  // If we have to deactivate the body
+
+        // For each proxy shape of the body
+        for (ProxyShape* shape = mProxyCollisionShapes; shape != NULL; shape = shape->mNext) {
+
+            // Remove the proxy shape from the collision detection
+            mWorld.mCollisionDetection.removeProxyCollisionShape(shape);
+        }
+
+        // Reset the contact manifold list of the body
+        resetContactManifoldsList();
+    }
+}
+
 // Ask the broad-phase to test again the collision shapes of the body for collision
 // (as if the body has moved).
 void CollisionBody::askForBroadPhaseCollisionCheck() const {
diff --git a/src/body/CollisionBody.h b/src/body/CollisionBody.h
index a70ad41a..98e4858b 100644
--- a/src/body/CollisionBody.h
+++ b/src/body/CollisionBody.h
@@ -134,6 +134,9 @@ class CollisionBody : public Body {
         /// Set the type of the body
         void setType(BodyType type);
 
+        /// Set whether or not the body is active
+        virtual void setIsActive(bool isActive);
+
         /// Return the current position and orientation
         const Transform& getTransform() const;