// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#ifndef __T_MESH_BUFFER_H_INCLUDED__
#define __T_MESH_BUFFER_H_INCLUDED__

#include "irrArray.h"
#include "IMeshBuffer.h"

namespace irr
{
namespace scene
{
	//! Template implementation of the IMeshBuffer interface
	template <class T>
	class CMeshBuffer : public IMeshBuffer
	{
	public:
		//! Default constructor for empty meshbuffer
		CMeshBuffer()
			: ChangedID_Vertex(1), ChangedID_Index(1)
			, MappingHint_Vertex(EHM_NEVER), MappingHint_Index(EHM_NEVER)
			, HWBuffer(NULL)
			, PrimitiveType(EPT_TRIANGLES)
		{
			#ifdef _DEBUG
			setDebugName("CMeshBuffer");
			#endif
		}


		//! Get material of this meshbuffer
		/** \return Material of this buffer */
		const video::SMaterial& getMaterial() const override
		{
			return Material;
		}


		//! Get material of this meshbuffer
		/** \return Material of this buffer */
		video::SMaterial& getMaterial() override
		{
			return Material;
		}


		//! Get pointer to vertices
		/** \return Pointer to vertices. */
		const void* getVertices() const override
		{
			return Vertices.const_pointer();
		}


		//! Get pointer to vertices
		/** \return Pointer to vertices. */
		void* getVertices() override
		{
			return Vertices.pointer();
		}


		//! Get number of vertices
		/** \return Number of vertices. */
		u32 getVertexCount() const override
		{
			return Vertices.size();
		}

		//! Get type of index data which is stored in this meshbuffer.
		/** \return Index type of this buffer. */
		video::E_INDEX_TYPE getIndexType() const override
		{
			return video::EIT_16BIT;
		}

		//! Get pointer to indices
		/** \return Pointer to indices. */
		const u16* getIndices() const override
		{
			return Indices.const_pointer();
		}


		//! Get pointer to indices
		/** \return Pointer to indices. */
		u16* getIndices() override
		{
			return Indices.pointer();
		}


		//! Get number of indices
		/** \return Number of indices. */
		u32 getIndexCount() const override
		{
			return Indices.size();
		}


		//! Get the axis aligned bounding box
		/** \return Axis aligned bounding box of this buffer. */
		const core::aabbox3d<f32>& getBoundingBox() const override
		{
			return BoundingBox;
		}


		//! Set the axis aligned bounding box
		/** \param box New axis aligned bounding box for this buffer. */
		//! set user axis aligned bounding box
		void setBoundingBox(const core::aabbox3df& box) override
		{
			BoundingBox = box;
		}


		//! Recalculate the bounding box.
		/** should be called if the mesh changed. */
		void recalculateBoundingBox() override
		{
			if (!Vertices.empty())
			{
				BoundingBox.reset(Vertices[0].Pos);
				const irr::u32 vsize = Vertices.size();
				for (u32 i=1; i<vsize; ++i)
					BoundingBox.addInternalPoint(Vertices[i].Pos);
			}
			else
				BoundingBox.reset(0,0,0);

		}


		//! Get type of vertex data stored in this buffer.
		/** \return Type of vertex data. */
		video::E_VERTEX_TYPE getVertexType() const override
		{
			return T::getType();
		}

		//! returns position of vertex i
		const core::vector3df& getPosition(u32 i) const override
		{
			return Vertices[i].Pos;
		}

		//! returns position of vertex i
		core::vector3df& getPosition(u32 i) override
		{
			return Vertices[i].Pos;
		}

		//! returns normal of vertex i
		const core::vector3df& getNormal(u32 i) const override
		{
			return Vertices[i].Normal;
		}

		//! returns normal of vertex i
		core::vector3df& getNormal(u32 i) override
		{
			return Vertices[i].Normal;
		}

		//! returns texture coord of vertex i
		const core::vector2df& getTCoords(u32 i) const override
		{
			return Vertices[i].TCoords;
		}

		//! returns texture coord of vertex i
		core::vector2df& getTCoords(u32 i) override
		{
			return Vertices[i].TCoords;
		}


		//! Append the vertices and indices to the current buffer
		/** Only works for compatible types, i.e. either the same type
		or the main buffer is of standard type. Otherwise, behavior is
		undefined.
		*/
		void append(const void* const vertices, u32 numVertices, const u16* const indices, u32 numIndices) override
		{
			if (vertices == getVertices())
				return;

			const u32 vertexCount = getVertexCount();
			u32 i;

			Vertices.reallocate(vertexCount+numVertices);
			for (i=0; i<numVertices; ++i)
			{
				Vertices.push_back(static_cast<const T*>(vertices)[i]);
				BoundingBox.addInternalPoint(static_cast<const T*>(vertices)[i].Pos);
			}

			Indices.reallocate(getIndexCount()+numIndices);
			for (i=0; i<numIndices; ++i)
			{
				Indices.push_back(indices[i]+vertexCount);
			}
		}


		//! Append the meshbuffer to the current buffer
		/** Only works for compatible types, i.e. either the same type
		or the main buffer is of standard type. Otherwise, behavior is
		undefined.
		\param other Meshbuffer to be appended to this one.
		*/
		void append(const IMeshBuffer* const other) override
		{
			/*
			if (this==other)
				return;

			const u32 vertexCount = getVertexCount();
			u32 i;

			Vertices.reallocate(vertexCount+other->getVertexCount());
			for (i=0; i<other->getVertexCount(); ++i)
			{
				Vertices.push_back(reinterpret_cast<const T*>(other->getVertices())[i]);
			}

			Indices.reallocate(getIndexCount()+other->getIndexCount());
			for (i=0; i<other->getIndexCount(); ++i)
			{
				Indices.push_back(other->getIndices()[i]+vertexCount);
			}
			BoundingBox.addInternalBox(other->getBoundingBox());
			*/
		}


		//! get the current hardware mapping hint
		E_HARDWARE_MAPPING getHardwareMappingHint_Vertex() const override
		{
			return MappingHint_Vertex;
		}

		//! get the current hardware mapping hint
		E_HARDWARE_MAPPING getHardwareMappingHint_Index() const override
		{
			return MappingHint_Index;
		}

		//! set the hardware mapping hint, for driver
		void setHardwareMappingHint( E_HARDWARE_MAPPING NewMappingHint, E_BUFFER_TYPE Buffer=EBT_VERTEX_AND_INDEX ) override
		{
			if (Buffer==EBT_VERTEX_AND_INDEX || Buffer==EBT_VERTEX)
				MappingHint_Vertex=NewMappingHint;
			if (Buffer==EBT_VERTEX_AND_INDEX || Buffer==EBT_INDEX)
				MappingHint_Index=NewMappingHint;
		}

		//! Describe what kind of primitive geometry is used by the meshbuffer
		void setPrimitiveType(E_PRIMITIVE_TYPE type) override
		{
			PrimitiveType = type;
		}

		//! Get the kind of primitive geometry which is used by the meshbuffer
		E_PRIMITIVE_TYPE getPrimitiveType() const override
		{
			return PrimitiveType;
		}

		//! flags the mesh as changed, reloads hardware buffers
		void setDirty(E_BUFFER_TYPE Buffer=EBT_VERTEX_AND_INDEX) override
		{
			if (Buffer==EBT_VERTEX_AND_INDEX ||Buffer==EBT_VERTEX)
				++ChangedID_Vertex;
			if (Buffer==EBT_VERTEX_AND_INDEX || Buffer==EBT_INDEX)
				++ChangedID_Index;
		}

		//! Get the currently used ID for identification of changes.
		/** This shouldn't be used for anything outside the VideoDriver. */
		u32 getChangedID_Vertex() const override {return ChangedID_Vertex;}

		//! Get the currently used ID for identification of changes.
		/** This shouldn't be used for anything outside the VideoDriver. */
		u32 getChangedID_Index() const override {return ChangedID_Index;}

		void setHWBuffer(void *ptr) const override {
			HWBuffer = ptr;
		}

		void *getHWBuffer() const override {
			return HWBuffer;
		}


		u32 ChangedID_Vertex;
		u32 ChangedID_Index;

		//! hardware mapping hint
		E_HARDWARE_MAPPING MappingHint_Vertex;
		E_HARDWARE_MAPPING MappingHint_Index;
		mutable void *HWBuffer;

		//! Material for this meshbuffer.
		video::SMaterial Material;
		//! Vertices of this buffer
		core::array<T> Vertices;
		//! Indices into the vertices of this buffer.
		core::array<u16> Indices;
		//! Bounding box of this meshbuffer.
		core::aabbox3d<f32> BoundingBox;
		//! Primitive type used for rendering (triangles, lines, ...)
		E_PRIMITIVE_TYPE PrimitiveType;
	};

	//! Standard meshbuffer
	typedef CMeshBuffer<video::S3DVertex> SMeshBuffer;
	//! Meshbuffer with two texture coords per vertex, e.g. for lightmaps
	typedef CMeshBuffer<video::S3DVertex2TCoords> SMeshBufferLightMap;
	//! Meshbuffer with vertices having tangents stored, e.g. for normal mapping
	typedef CMeshBuffer<video::S3DVertexTangents> SMeshBufferTangents;
} // end namespace scene
} // end namespace irr

#endif