/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, 
including commercial applications, and to alter it and redistribute it freely, 
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/

#ifndef BT_TRIANGLE_INDEX_VERTEX_ARRAY_H
#define BT_TRIANGLE_INDEX_VERTEX_ARRAY_H

#include "btStridingMeshInterface.h"
#include "../../LinearMath/btAlignedObjectArray.h"
#include "../../LinearMath/btScalar.h"

///The btIndexedMesh indexes a single vertex and index array. Multiple btIndexedMesh objects can be passed into a btTriangleIndexVertexArray using addIndexedMesh.
///Instead of the number of indices, we pass the number of triangles.
ATTRIBUTE_ALIGNED16(struct)
btIndexedMesh
{
	BT_DECLARE_ALIGNED_ALLOCATOR();

	int m_numTriangles;
	const unsigned char* m_triangleIndexBase;
	// Size in byte of the indices for one triangle (3*sizeof(index_type) if the indices are tightly packed)
	int m_triangleIndexStride;
	int m_numVertices;
	const unsigned char* m_vertexBase;
	// Size of a vertex, in bytes
	int m_vertexStride;

	btIndexedMesh()
	{
	}
};

typedef btAlignedObjectArray<btIndexedMesh> IndexedMeshArray;

///The btTriangleIndexVertexArray allows to access multiple triangle meshes, by indexing into existing triangle/index arrays.
///Additional meshes can be added using addIndexedMesh
///No duplicate is made of the vertex/index data, it only indexes into external vertex/index arrays.
///So keep those arrays around during the lifetime of this btTriangleIndexVertexArray.
ATTRIBUTE_ALIGNED16(class)
btTriangleIndexVertexArray : public btStridingMeshInterface
{
protected:
	IndexedMeshArray m_indexedMeshes;
	int m_pad[2];
	mutable int m_hasAabb;  // using int instead of bool to maintain alignment
	mutable btVector3 m_aabbMin;
	mutable btVector3 m_aabbMax;

public:
	BT_DECLARE_ALIGNED_ALLOCATOR();

	btTriangleIndexVertexArray() : m_hasAabb(0)
	{
	}

	virtual ~btTriangleIndexVertexArray();

	//just to be backwards compatible
	btTriangleIndexVertexArray(int numTriangles, int* triangleIndexBase, int triangleIndexStride, int numVertices, btScalar* vertexBase, int vertexStride);

	void addIndexedMesh(const btIndexedMesh& mesh)
	{
		m_indexedMeshes.push_back(mesh);
	}

	virtual void getLockedVertexIndexBase(unsigned char** vertexbase, int& numverts, int& vertexStride, unsigned char** indexbase, int& indexstride, int& numfaces, int subpart = 0);

	virtual void getLockedReadOnlyVertexIndexBase(const unsigned char** vertexbase, int& numverts, int& vertexStride, const unsigned char** indexbase, int& indexstride, int& numfaces, int subpart = 0) const;

	/// unLockVertexBase finishes the access to a subpart of the triangle mesh
	/// make a call to unLockVertexBase when the read and write access (using getLockedVertexIndexBase) is finished
	virtual void unLockVertexBase(int subpart) { (void)subpart; }

	virtual void unLockReadOnlyVertexBase(int subpart) const { (void)subpart; }

	/// getNumSubParts returns the number of separate subparts
	/// each subpart has a continuous array of vertices and indices
	virtual int getNumSubParts() const
	{
		return (int)m_indexedMeshes.size();
	}

	IndexedMeshArray& getIndexedMeshArray()
	{
		return m_indexedMeshes;
	}

	const IndexedMeshArray& getIndexedMeshArray() const
	{
		return m_indexedMeshes;
	}

	virtual void preallocateVertices(int numverts) { (void)numverts; }
	virtual void preallocateIndices(int numindices) { (void)numindices; }

	virtual bool hasPremadeAabb() const;
	virtual void setPremadeAabb(const btVector3& aabbMin, const btVector3& aabbMax) const;
	virtual void getPremadeAabb(btVector3 * aabbMin, btVector3 * aabbMax) const;
};

#endif  //BT_TRIANGLE_INDEX_VERTEX_ARRAY_H