Add a publicly configurable binding between camera target and scene node...

Add a publicly configurable binding between camera target and scene node rotation.  By default, they are independent.  FPS cameras have their scene node rotation follow their target, which restores the <=1.4.2 behaviour.  This is Work In Progress, as the ordering of events isn't quite correct yet: there's a visible lag between FPS camera scene node childrens' relative position catching up with the camera rotation.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@1748 dfc29bdd-3216-0410-991c-e03cc46cb475

include/ICameraSceneNode.h

@@ -125,6 +125,28 @@ namespace scene
 			return IsOrthogonal;
 		}
 
+		//! Determines how the camera's target and its scene node rotation are bound together.
+		typedef enum _TargetAndRotationBinding
+		{
+			//! The target and scene node rotation are independent.
+			/** This is the default for most cameras. */
+			TARGET_AND_ROTATION_INDEPENDENT = 0x10000,
+
+			//! The scene node rotation will be updated so that +Z points at the target location.
+			/** This is the default for FPS camera */
+			ROTATION_FOLLOWS_TARGET,
+
+			//! The target position will be updated to be along the node's +Z axis
+			TARGET_FOLLOWS_ROTATION
+
+		} TargetAndRotationBinding;
+
+		//! Set the binding between the camera's rotation adn target.
+		virtual void setTargetAndRotationBinding(TargetAndRotationBinding binding) = 0;
+
+		//! Gets the binding between the camera's rotation and target.
+		virtual TargetAndRotationBinding getTargetAndRotationBinding(void) const = 0;
+
 	protected:
 
 		bool IsOrthogonal;

source/Irrlicht/CCameraSceneNode.cpp

@@ -199,13 +199,28 @@ void CCameraSceneNode::recalculateProjectionMatrix()
 //! prerender
 void CCameraSceneNode::OnRegisterSceneNode()
 {
-	// if upvector and vector to the target are the same, we have a
-	// problem. so solve this problem:
-
 	core::vector3df pos = getAbsolutePosition();
 	core::vector3df tgtv = Target - pos;
 	tgtv.normalize();
 
+	switch(Binding)
+	{
+	case ROTATION_FOLLOWS_TARGET:
+		setRotation(tgtv.getHorizontalAngle());
+		break;
+
+	case TARGET_FOLLOWS_ROTATION:
+		tgtv = getRotation().rotationToDirection(); // Already normalised
+		setTarget(pos + tgtv);
+		break;
+
+	default:
+		break;
+	}
+
+
+	// if upvector and vector to the target are the same, we have a
+	// problem. so solve this problem:
 	core::vector3df up = UpVector;
 	up.normalize();
 
@@ -257,14 +272,6 @@ void CCameraSceneNode::recalculateViewArea()
 {
 	ViewArea.cameraPosition = getAbsolutePosition();
 	ViewArea.setFrom ( ViewArea.Matrices [ SViewFrustum::ETS_VIEW_PROJECTION_3 ] );
-/*
-	video::IVideoDriver* driver = SceneManager->getVideoDriver();
-	if ( driver)
-	{
-		driver->setTransform(video::ETS_PROJECTION, ViewArea.Matrices [ video::ETS_PROJECTION ] );
-		driver->setTransform(video::ETS_VIEW, ViewArea.Matrices [ video::ETS_VIEW ] );
-	}
-*/
 }
 
 
@@ -279,6 +286,7 @@ void CCameraSceneNode::serializeAttributes(io::IAttributes* out, io::SAttributeR
 	out->addFloat("Aspect", Aspect);
 	out->addFloat("ZNear", ZNear);
 	out->addFloat("ZFar", ZFar);
+	out->addInt("Binding", (int)Binding);
 }
 
 
@@ -294,11 +302,28 @@ void CCameraSceneNode::deserializeAttributes(io::IAttributes* in, io::SAttribute
 	ZNear = in->getAttributeAsFloat("ZNear");
 	ZFar = in->getAttributeAsFloat("ZFar");
 
+	Binding = (ICameraSceneNode::TargetAndRotationBinding)in->getAttributeAsInt("Binding");
+	if(0 == Binding)
+		Binding = TARGET_AND_ROTATION_INDEPENDENT;
+
 	recalculateProjectionMatrix();
 	recalculateViewArea();	
 }
 
 
+//! Set the binding between the camera's rotation adn target.
+void CCameraSceneNode::setTargetAndRotationBinding(TargetAndRotationBinding binding)
+{
+	Binding = binding;
+}
+
+//! Gets the binding between the camera's rotation and target.
+ICameraSceneNode::TargetAndRotationBinding CCameraSceneNode::getTargetAndRotationBinding(void) const
+{
+	return Binding;
+}
+
+
 } // end namespace
 } // end namespace
 

source/Irrlicht/CCameraSceneNode.h

@@ -120,6 +120,12 @@ namespace scene
 		//! Returns type of the scene node
 		virtual ESCENE_NODE_TYPE getType() const { return ESNT_CAMERA; }
 
+		//! Set the binding between the camera's rotation adn target.
+		virtual void setTargetAndRotationBinding(TargetAndRotationBinding binding);
+
+		//! Gets the binding between the camera's rotation and target.
+		virtual TargetAndRotationBinding getTargetAndRotationBinding(void) const;
+
 	protected:
 
 		void recalculateProjectionMatrix();
@@ -136,6 +142,8 @@ namespace scene
 		SViewFrustum ViewArea;
 
 		bool InputReceiverEnabled;
+
+		TargetAndRotationBinding Binding;
 	};
 
 } // end namespace

source/Irrlicht/CSceneManager.cpp

@@ -667,6 +667,9 @@ ICameraSceneNode* CSceneManager::addCameraSceneNodeFPS(ISceneNode* parent,
 	ISceneNodeAnimator* anm = new CSceneNodeAnimatorCameraFPS(CursorControl, rotateSpeed, 
 		moveSpeed, jumpSpeed, keyMapArray, keyMapSize, noVerticalMovement);
 
+	// Have the node's rotation follow its target. This is consistent with 1.4.2 and below.
+	node->setTargetAndRotationBinding(ICameraSceneNode::ROTATION_FOLLOWS_TARGET);
+
 	node->addAnimator(anm);
 	anm->drop();
 	node->drop();

source/Irrlicht/CSceneNodeAnimatorCameraFPS.cpp

@@ -103,6 +103,7 @@ void CSceneNodeAnimatorCameraFPS::animateNode(ISceneNode* node, u32 timeMs)
 
 	if (firstUpdate)
 	{
+		camera->updateAbsolutePosition();
 		if (CursorControl && camera)
 		{
 			CursorControl->setPosition(0.5f, 0.5f);
@@ -198,7 +199,7 @@ void CSceneNodeAnimatorCameraFPS::animateNode(ISceneNode* node, u32 timeMs)
 	if (CursorKeys[3])
 		pos -= strafevect * timeDiff * MoveSpeed;
 
-	// jumping ( need's a gravity , else it's a fly to the World-UpVector )
+	// jumping ( needs a gravity , else it's a fly to the World-UpVector )
 	if (CursorKeys[4])
 	{
 		pos += camera->getUpVector() * timeDiff * JumpSpeed;