// Copyright (C) 2002-2008 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h

#ifndef __I_MESH_BUFFER_H_INCLUDED__
#define __I_MESH_BUFFER_H_INCLUDED__

#include "IReferenceCounted.h"
#include "SMaterial.h"
#include "aabbox3d.h"
#include "S3DVertex.h"
#include "EHardwareBufferFlags.h"

namespace irr
{
namespace scene
{

	//! Enumeration for all primitive types there are.
	enum E_PRIMITIVE_TYPE
	{
		//! All vertices are non-connected points.
		EPT_POINTS=0,

		//! All vertices form a single connected line.
		EPT_LINE_STRIP,

		//! Just as LINE_STRIP, but the last and the first vertex is also connected.
		EPT_LINE_LOOP,

		//! Every two vertices are connected creating n/2 lines.
		EPT_LINES,

		//! After the first two vertices each vertex defines a new triangle.
		//! Always the two last and the new one form a new triangle.
		EPT_TRIANGLE_STRIP,

		//! After the first two vertices each vertex defines a new triangle.
		//! All around the common first vertex.
		EPT_TRIANGLE_FAN,

		//! Explicitly set all vertices for each triangle.
		EPT_TRIANGLES,

		//! After the first two vertices each further tw vetices create a quad with the preceding two.
		EPT_QUAD_STRIP,

		//! Every four vertices create a quad.
		EPT_QUADS,

		//! Just as LINE_LOOP, but filled.
		EPT_POLYGON,

		//! The single vertices are expanded to quad billboards on the GPU.
		EPT_POINT_SPRITES
	};

	enum E_BUFFER_TYPE
	{
		EBT_NONE=0,
		EBT_VERTEX,
		EBT_INDEX,
		EBT_VERTEX_AND_INDEX
	};

	//! Struct for holding a mesh with a single material
	/** SMeshBuffer is a simple implementation of a MeshBuffer. */
	class IMeshBuffer : public virtual IReferenceCounted
	{
	public:

		//! Get the material of this meshbuffer
		/** \return Material of this buffer. */
		virtual video::SMaterial& getMaterial() = 0;

		//! Get the material of this meshbuffer
		/** \return Material of this buffer. */
		virtual const video::SMaterial& getMaterial() const = 0;

		//! Get type of vertex data which is stored in this meshbuffer.
		/** \return Vertex type of this buffer. */
		virtual video::E_VERTEX_TYPE getVertexType() const = 0;

		//! Get access to vertex data. The data is an array of vertices.
		/** Which vertex type is used can be determined by getVertexType().
		\return Pointer to array of vertices. */
		virtual const void* getVertices() const = 0;

		//! Get access to vertex data. The data is an array of vertices.
		/** Which vertex type is used can be determined by getVertexType().
		\return Pointer to array of vertices. */
		virtual void* getVertices() = 0;

		//! Get amount of vertices in meshbuffer.
		/** \return Number of vertices in this buffer. */
		virtual u32 getVertexCount() const = 0;

		//! Get access to Indices.
		/** \return Pointer to indices array. */
		virtual const u16* getIndices() const = 0;

		//! Get access to Indices.
		/** \return Pointer to indices array. */
		virtual u16* getIndices() = 0;

		//! Get amount of indices in this meshbuffer.
		/** \return Number of indices in this buffer. */
		virtual u32 getIndexCount() const = 0;

		//! Get the axis aligned bounding box of this meshbuffer.
		/** \return Axis aligned bounding box of this buffer. */
		virtual const core::aabbox3df& getBoundingBox() const = 0;

		//! Set axis aligned bounding box
		/** \param box User defined axis aligned bounding box to use
		for this buffer. */
		virtual void setBoundingBox(const core::aabbox3df& box) = 0;

		//! Recalculates the bounding box. Should be called if the mesh changed.
		virtual void recalculateBoundingBox() = 0;

		//! returns position of vertex i
		virtual const core::vector3df& getPosition(u32 i) const = 0;

		//! returns position of vertex i
		virtual core::vector3df& getPosition(u32 i) = 0;

		//! returns normal of vertex i
		virtual const core::vector3df& getNormal(u32 i) const = 0;

		//! returns normal of vertex i
		virtual core::vector3df& getNormal(u32 i) = 0;

		//! Append the vertices and indices to the current buffer
		/** Only works for compatible vertex types.
		\param vertices Pointer to a vertex array.
		\param numVertices Number of vertices in the array.
		\param indices Pointer to index array.
		\param numIndices Number of indices in array. */
		virtual void append(const void* const vertices, u32 numVertices, const u16* const indices, u32 numIndices) = 0;

		//! Append the meshbuffer to the current buffer
		/** Only works for compatible vertex types
		\param other Buffer to append to this one. */
		virtual void append(const IMeshBuffer* const other) = 0;

		//! get the current hardware mapping hint
		virtual const E_HARDWARE_MAPPING getHardwareMappingHint() const = 0;

		//! set the hardware mapping hint, for driver
		virtual void setHardwareMappingHint( E_HARDWARE_MAPPING NewMappingHint ) = 0;

		//! flags the meshbuffer as changed, reloads hardware buffers
		virtual void setDirty(E_BUFFER_TYPE Buffer=EBT_VERTEX_AND_INDEX) = 0;

		//to be spit into vertex and index buffers:
		//! Get the currently used ID for identification of changes.
		/** This shouldn't be used for anything outside the VideoDriver. */
		virtual const u32 getChangedID_Vertex() const = 0;

		//! Get the currently used ID for identification of changes.
		/** This shouldn't be used for anything outside the VideoDriver. */
		virtual const u32 getChangedID_Index() const = 0;

		u32 HardwareHint;
	};

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

#endif

