// Copyright (C) 2002-2004 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in Irrlicht.h

#ifndef __C_SCENE_NODE_ANIMATOR_COLLISION_RESPONSE_H_INCLUDED__
#define __C_SCENE_NODE_ANIMATOR_COLLISION_RESPONSE_H_INCLUDED__

#include "ISceneNodeAnimatorCollisionResponse.h"

namespace irr
{
namespace scene
{

	//! Special scene node animator for doing automatic collision detection and response.
	/** This scene node animator can be attached to any scene node modifying it in that
	way, that it cannot move through walls of the world, is influenced by gravity and
	acceleration. This animator is useful for example for first person shooter 
	games. Attach it for example to a first person shooter camera, and the camera will
	behave as the player control in a first person shooter game: The camera stops and
	slides at walls, walks up stairs, falls down if there is no floor under it, and so on.
	*/
	class CSceneNodeAnimatorCollisionResponse : public ISceneNodeAnimatorCollisionResponse
	{
	public:

		//! constructor
		CSceneNodeAnimatorCollisionResponse(ISceneManager* scenemanager,
			ITriangleSelector* world, ISceneNode* object, 
			const core::vector3df& ellipsoidRadius = core::vector3df(30,60,30),
			const core::vector3df& gravityPerSecond = core::vector3df(0,-100.0f,0),
			f32 accelerationPerSecond=100.0f,
			const core::vector3df& ellipsoidTranslation = core::vector3df(0,0,0),
			f32 slidingSpeed = 0.0005f);

		//! destructor
		virtual ~CSceneNodeAnimatorCollisionResponse();

		//! Returns if the attached scene node is falling, which means that
		//! there is no blocking wall from the scene node in the direction of
		//! the gravity.
		virtual bool isFalling();

		//! Sets the radius of the ellipsoid with which collision detection and
		//! response is done. 
		virtual void setEllipsoidRadius(const core::vector3df& radius);

		//! Returns the radius of the ellipsoid with wich the collision detection and
		//! response is done.
		virtual core::vector3df getEllipsoidRadius() const;

		//! Sets the gravity of the environment.
		virtual void setGravity(const core::vector3df& gravity);

		//! Returns current vector of gravity.
		virtual core::vector3df getGravity() const;

		//! Sets the translation of the ellipsoid for collision detection.
		virtual void setEllipsoidTranslation(core::vector3df translation);

		//! Returns the translation of the ellipsoid for collision detection.
		virtual core::vector3df getEllipsoidTranslation() const;

		//! Returns the acceleration per second, if the scene node is falling down.
		virtual f32 getAccelerationPerSecond() const;

		//! Sets a new acceleration per second value.
		virtual void setAccelerationPerSecond(f32 accel);

		//! Sets a triangle selector holding all triangles of the world with which
		//! the scene node may collide.
		virtual void setWorld(ITriangleSelector* newWorld);

		//! Returns the current triangle selector containing all triangles for
		//! collision detection.
		virtual ITriangleSelector* getWorld() const;

		//! animates a scene node
		virtual void animateNode(ISceneNode* node, u32 timeMs);

	private:

		core::vector3df LastPosition;
		core::vector3df Radius;
		core::vector3df Gravity;
		core::vector3df Translation;
		
		ITriangleSelector* World;
		ISceneNode* Object;
		ISceneManager* SceneManager;
		u32 LastTime;
		u32 FallStartTime;
		f32 AccelerationPerSecond;
		f32 SlidingSpeed;
		bool Falling;

		core::triangle3df RefTriangle;
	};

} // end namespace scene
} // end namespace irr

#endif

