// 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 IRR_T_MESH_BUFFER_H_INCLUDED
#define IRR_T_MESH_BUFFER_H_INCLUDED

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

namespace irr
{
namespace scene
{
	//! Template implementation of the IMeshBuffer interface for 16-bit buffers
	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)
			, PrimitiveType(EPT_TRIANGLES)
		{
			#ifdef _DEBUG
			setDebugName("CMeshBuffer");
			#endif
		}


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


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


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


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


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

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

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


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


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


		//! Get the axis aligned bounding box
		/** \return Axis aligned bounding box of this buffer. */
		virtual const core::aabbox3d<f32>& getBoundingBox() const IRR_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
		virtual void setBoundingBox(const core::aabbox3df& box) IRR_OVERRIDE
		{
			BoundingBox = box;
		}


		//! Recalculate the bounding box.
		/** should be called if the mesh changed. */
		virtual void recalculateBoundingBox() IRR_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. */
		virtual video::E_VERTEX_TYPE getVertexType() const IRR_OVERRIDE
		{
			return T::getType();
		}

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

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

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

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

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

		//! returns texture coord of vertex i
		virtual core::vector2df& getTCoords(u32 i) IRR_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.
		*/
		virtual void append(const void* const vertices, u32 numVertices, const u16* const indices, u32 numIndices) IRR_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.
		*/
		virtual void append(const IMeshBuffer* const other) IRR_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
		virtual E_HARDWARE_MAPPING getHardwareMappingHint_Vertex() const IRR_OVERRIDE
		{
			return MappingHint_Vertex;
		}

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

		//! set the hardware mapping hint, for driver
		virtual void setHardwareMappingHint( E_HARDWARE_MAPPING NewMappingHint, E_BUFFER_TYPE Buffer=EBT_VERTEX_AND_INDEX ) IRR_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
		virtual void setPrimitiveType(E_PRIMITIVE_TYPE type) IRR_OVERRIDE
		{
			PrimitiveType = type;
		}

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

		//! flags the mesh as changed, reloads hardware buffers
		virtual void setDirty(E_BUFFER_TYPE Buffer=EBT_VERTEX_AND_INDEX) IRR_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. */
		virtual u32 getChangedID_Vertex() const IRR_OVERRIDE {return ChangedID_Vertex;}

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

		//! Returns type of the class implementing the IMeshBuffer
		virtual EMESH_BUFFER_TYPE getType() const  IRR_OVERRIDE
		{
			return getTypeT();
		}

		//! Create copy of the meshbuffer
		virtual IMeshBuffer* createClone(int cloneFlags) const IRR_OVERRIDE
		{
			CMeshBuffer<T> * clone = new CMeshBuffer<T>();

			if (cloneFlags & ECF_VERTICES)
			{
				clone->Vertices = Vertices;
				clone->BoundingBox = BoundingBox;
			}

			if (cloneFlags & ECF_INDICES)
			{
				clone->Indices = Indices;
			}

			clone->PrimitiveType = PrimitiveType;
			clone->Material = getMaterial();
			clone->MappingHint_Vertex = MappingHint_Vertex;
			clone->MappingHint_Index = MappingHint_Index;

			return clone;
		}

		//! Returns type of the class implementing the IMeshBuffer for template specialization
		// Minor note: Some compilers (VS) allow directly specializing the virtual function,
		// but this will fail on other compilers (GCC). So using a helper function.
		EMESH_BUFFER_TYPE getTypeT() const;

		u32 ChangedID_Vertex;
		u32 ChangedID_Index;

		//! hardware mapping hint
		E_HARDWARE_MAPPING MappingHint_Vertex;
		E_HARDWARE_MAPPING MappingHint_Index;

		//! 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;

	//! partial specialization to return types
	template <>
	inline EMESH_BUFFER_TYPE CMeshBuffer<video::S3DVertex>::getTypeT() const
	{
		return EMBT_STANDARD;
	}
	template <>
	inline EMESH_BUFFER_TYPE CMeshBuffer<video::S3DVertex2TCoords>::getTypeT() const
	{
		return EMBT_LIGHTMAP;
	}
	template <>
	inline EMESH_BUFFER_TYPE CMeshBuffer<video::S3DVertexTangents>::getTypeT() const
	{
		return EMBT_TANGENTS;
	}


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

#endif