// Copyright (C) 2002-2009 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

// The code for the TerrainTriangleSelector is based on the GeoMipMapSelector
// developed by Spintz. He made it available for Irrlicht and allowed it to be 
// distributed under this licence. I only modified some parts. A lot of thanks go to him. 

#ifndef __C_TERRAIN_TRIANGLE_SELECTOR_H__
#define __C_TERRAIN_TRIANGLE_SELECTOR_H__

#include "ITriangleSelector.h"
#include "irrArray.h"

namespace irr
{
namespace scene
{

class ITerrainSceneNode;

//! Triangle Selector for the TerrainSceneNode
//! The code for the TerrainTriangleSelector is based on the GeoMipMapSelector
//! developed by Spintz. He made it available for Irrlicht and allowed it to be 
//! distributed under this licence. I only modified some parts. A lot of thanks go to him. 
class CTerrainTriangleSelector : public ITriangleSelector
{
public:

	//! Constructs a selector based on an IGeoMipMapSceneNode
	CTerrainTriangleSelector(ITerrainSceneNode* node, s32 LOD);

	//! Destructor
	virtual ~CTerrainTriangleSelector();

	//! Clears and sets triangle data
	virtual void setTriangleData (ITerrainSceneNode* node, s32 LOD);

	//! Gets all triangles.
	void getTriangles(core::triangle3df* triangles, s32 arraySize, s32& outTriangleCount,
		const core::matrix4* transform=0) const;

	//! Gets all triangles which lie within a specific bounding box.
	void getTriangles(core::triangle3df* triangles, s32 arraySize, s32& outTriangleCount,
		const core::aabbox3d<f32>& box, const core::matrix4* transform=0) const;

	//! Gets all triangles which have or may have contact with a 3d line.
	virtual void getTriangles(core::triangle3df* triangles, s32 arraySize,
		s32& outTriangleCount, const core::line3d<f32>& line, 
		const core::matrix4* transform=0) const;

	//! Returns amount of all available triangles in this selector
	virtual s32 getTriangleCount() const;

	//! Return the scene node associated with a given triangle.
	/** ITerrainSceneNode is an ISceneNode, we just don't know it yet. */
	virtual const ISceneNode* getSceneNodeForTriangle(u32 triangleIndex) const
		{ return (ISceneNode*)SceneNode; }

private:

	friend class CTerrainSceneNode;

	struct SGeoMipMapTrianglePatch
	{
		core::array<core::triangle3df>	Triangles;
		s32				NumTriangles;
		core::aabbox3df			Box;
	};

	struct SGeoMipMapTrianglePatches
	{
		SGeoMipMapTrianglePatches() :
			NumPatches(0), TotalTriangles(0)
		{
		}

		core::array<SGeoMipMapTrianglePatch>	TrianglePatchArray;
		s32					NumPatches;
		u32					TotalTriangles;
	};

	ITerrainSceneNode*		SceneNode;
	SGeoMipMapTrianglePatches	TrianglePatches;
};

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


#endif // __C_TERRAIN_TRIANGLE_SELECTOR_H__