assimp/code/VertexTriangleAdjacency.h

/*
Open Asset Import Library (ASSIMP)
----------------------------------------------------------------------

Copyright (c) 2006-2008, ASSIMP Development Team
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*/

/** @file Defines a helper class to compute a vertex-triangle adjacency map */
#ifndef AI_VTADJACENCY_H_INC
#define AI_VTADJACENCY_H_INC

#include "BaseProcess.h"
#include "../include/aiTypes.h"
#include "../include/aiAssert.h"

struct aiMesh;

namespace Assimp
{

// ---------------------------------------------------------------------------
/** The VertexTriangleAdjacency class computes a vertex-triangle
 *  adjacency map from a given index buffer.
 *
 *  @note The input data is expected to be triangulated.
 */
class ASSIMP_API VertexTriangleAdjacency
{
public:


	/** Construction from an existing index buffer
	 * @param pcFaces Index buffer
	 * @param iNumFaces Number of faces in the buffer
	 * @param iNumVertices Number of referenced vertices. This value
	 *   is computed automatically if 0 is specified.
	 * @param bComputeNumTriangles If you want the class to compute
	 *   a list which contains the number of referenced triangles
	 *   per vertex - pass true.
	 */
	VertexTriangleAdjacency(aiFace* pcFaces,unsigned int iNumFaces,
		unsigned int iNumVertices = 0,
		bool bComputeNumTriangles = true);


	/** Destructor
	 */
	~VertexTriangleAdjacency();


	/** Get all triangles adjacent to a vertex
	 * @param iVertIndex Index of the vertex
	 * @return A pointer to the adjacency list
	 */
	inline unsigned int* GetAdjacentTriangles(unsigned int iVertIndex) const
	{
		ai_assert(iVertIndex < iNumVertices);

		const unsigned int ofs = mOffsetTable[iVertIndex];
		return &mAdjacencyTable[ofs];
	}


	/** Get the number of triangles that are referenced by
	 *  a vertex. This function returns a reference that can be modified
	 * @param iVertIndex Index of the vertex
	 * @return Number of referenced triangles
	 */
	inline unsigned int& GetNumTrianglesPtr(unsigned int iVertIndex)
	{
		ai_assert(iVertIndex < iNumVertices && NULL != mLiveTriangles);
		return mLiveTriangles[iVertIndex];
	}


public:

	//! Offset table
	unsigned int* mOffsetTable;

	//! Adjacency table
	unsigned int* mAdjacencyTable;

	//! Table containing the number of referenced triangles per vertex
	unsigned int* mLiveTriangles;

	//! Debug: Number of referenced vertices
	unsigned int iNumVertices;

};
}

#endif // !! AI_VTADJACENCY_H_INC