From ada4616fd3932ee6e8883d420108a203014573f3 Mon Sep 17 00:00:00 2001
From: gugus <gus_512@hotmail.com>
Date: Tue, 22 Feb 2011 20:53:02 +0100
Subject: [PATCH] add raycasting

---
 bullet/physic.cpp | 37 +++++++++++++++++++++++++++++++++----
 bullet/physic.hpp | 25 +++++++++++++++++++++++--
 2 files changed, 56 insertions(+), 6 deletions(-)

diff --git a/bullet/physic.cpp b/bullet/physic.cpp
index d5c504cfd..76dabce5d 100644
--- a/bullet/physic.cpp
+++ b/bullet/physic.cpp
@@ -31,7 +31,7 @@ namespace Physic
 		transform.setIdentity();
 
 		// External capsule
-		externalGhostObject = new btPairCachingGhostObject();
+		externalGhostObject = new PairCachingGhostObject(name);
 		externalGhostObject->setWorldTransform( transform );
 
 		btScalar externalCapsuleHeight = 50;
@@ -44,7 +44,7 @@ namespace Physic
 		externalGhostObject->setCollisionFlags( btCollisionObject::CF_CHARACTER_OBJECT );
 
 		// Internal capsule
-		internalGhostObject = new btPairCachingGhostObject();
+		internalGhostObject = new PairCachingGhostObject(name);
 		internalGhostObject->setWorldTransform( transform );
 		//internalGhostObject->getBroadphaseHandle()->s
 		btScalar internalCapsuleHeight =  20;
@@ -196,13 +196,20 @@ namespace Physic
 		//create the real body
 		btRigidBody::btRigidBodyConstructionInfo CI = btRigidBody::btRigidBodyConstructionInfo(0,newMotionState,shape->Shape);
 		RigidBody* body = new RigidBody(CI,name);
-
+        body->collide = shape->collide;
 		return body;
 	}
 
 	void PhysicEngine::addRigidBody(RigidBody* body)
 	{
-		dynamicsWorld->addRigidBody(body,COL_WORLD,COL_WORLD|COL_ACTOR_INTERNAL|COL_ACTOR_EXTERNAL);
+        if(body->collide)
+        {
+		    dynamicsWorld->addRigidBody(body,COL_WORLD,COL_WORLD|COL_ACTOR_INTERNAL|COL_ACTOR_EXTERNAL);
+        }
+        else
+        {
+            dynamicsWorld->addRigidBody(body,COL_WORLD,COL_NOTHING);
+        }
 		body->setActivationState(DISABLE_DEACTIVATION);
 		RigidBodyMap[body->mName] = body;
 	}
@@ -272,4 +279,26 @@ namespace Physic
 	void PhysicEngine::emptyEventLists(void)
 	{
 	}
+
+    std::pair<std::string,float> PhysicEngine::rayTest(btVector3& from,btVector3& to)
+    {
+        std::string name = "";
+        float d = -1.;
+        btCollisionWorld::ClosestRayResultCallback resultCallback(from, to);
+        dynamicsWorld->rayTest(from, to, resultCallback);
+
+        if (resultCallback.hasHit())
+        {
+            if(resultCallback.m_collisionFilterGroup == COL_WORLD)
+            {
+                name = static_cast<RigidBody*>(resultCallback.m_collisionObject)->mName;
+            }
+            if(resultCallback.m_collisionFilterGroup == COL_ACTOR_EXTERNAL || resultCallback.m_collisionFilterGroup == COL_ACTOR_INTERNAL)
+            {
+                name = static_cast<PairCachingGhostObject*>(resultCallback.m_collisionObject)->mName;
+            }
+            d = resultCallback.m_closestHitFraction;
+        }
+        return std::pair<std::string,float>(name,d);
+    }
 }};
\ No newline at end of file
diff --git a/bullet/physic.hpp b/bullet/physic.hpp
index 5fdc03e7d..062e69e02 100644
--- a/bullet/physic.hpp
+++ b/bullet/physic.hpp
@@ -34,6 +34,19 @@ namespace Physic
 	class CMotionState;
 	struct PhysicEvent;
 
+    /**
+    *This is just used to be able to name objects. 
+    */
+    class PairCachingGhostObject : public btPairCachingGhostObject
+    {
+    public:
+        PairCachingGhostObject(std::string name)
+            :btPairCachingGhostObject(),mName(name)
+        {
+        }
+        std::string mName;
+    };
+
 	/**
 	*A physic Actor use a modifed KinematicCharacterController taken in the bullet forum.
 	*/
@@ -63,10 +76,10 @@ namespace Physic
 
 		btKinematicCharacterController* mCharacter;
 
-		btPairCachingGhostObject* internalGhostObject;
+		PairCachingGhostObject* internalGhostObject;
 		btCollisionShape* internalCollisionShape;
 
-		btPairCachingGhostObject* externalGhostObject;
+		PairCachingGhostObject* externalGhostObject;
 		btCollisionShape* externalCollisionShape;
 
 		std::string mName;
@@ -82,6 +95,9 @@ namespace Physic
 	public:
 		RigidBody(btRigidBody::btRigidBodyConstructionInfo& CI,std::string name);
 		std::string mName;
+
+        //is this body used for raycasting only?
+        bool collide;
 	};
 
 	/**
@@ -161,6 +177,11 @@ namespace Physic
 		*/
 		void setDebugRenderingMode(int mode);
 
+        /**
+        *Return the closest object hit by a ray. If there are no objects, it will return ("",-1).
+        */
+        std::pair<std::string,float> rayTest(btVector3& from,btVector3& to);
+
 		//event list of non player object
 		std::list<PhysicEvent> NPEventList;