// 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;
		}

		//! returns color of vertex i
		virtual video::SColor& getColor(u32 i) IRR_OVERRIDE
		{
			return Vertices[i].Color;
		}

		//! returns color of vertex i
		virtual const video::SColor& getColor(u32 i) const IRR_OVERRIDE
		{
			return Vertices[i].Color;
		}

		//! 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. Also can't append it's own vertices/indices to itself.
		*/
		virtual void append(const void* const vertices, u32 numVertices, const u16* const indices, u32 numIndices) IRR_OVERRIDE
		{
			if (vertices == getVertices() || indices == getIndices())	// can't do that because we're doing reallocations on those blocks
				return;

			const u32 vertexCount = getVertexCount();
			u32 i;

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

			setDirty();
		}


		//! Append the meshbuffer to the current buffer
		virtual void append(const IMeshBuffer* const other) IRR_OVERRIDE
		{
			if ( getVertexType() != other->getVertexType() )
				return;

			append(other->getVertices(), other->getVertexCount(), other->getIndices(), other->getIndexCount());
		}


		//! 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