GameStar 2006 March/Gamestar_82_2006-03_dvd.iso/DVDStar/Editace/quake4_sdkv10.exe/source/idlib/geometry/Surface.h

C/C++ Source or Header | 2005-11-14 | 6KB | 207 lines

#ifndef __SURFACE_H__
#define __SURFACE_H__

/*
===============================================================================

    Surface base class.

    A surface is tesselated to a triangle mesh with each edge shared by
    at most two triangles.

===============================================================================
*/

typedef struct surfaceEdge_s {
    int                        verts[2];    // edge vertices always with ( verts[0] < verts[1] )
    int                        tris[2];    // edge triangles
} surfaceEdge_t;


class idSurface {
public:
                            idSurface( void );
                            explicit idSurface( const idSurface &surf );
                            explicit idSurface( const idDrawVert *verts, const int numVerts, const int *indexes, const int numIndexes );
                            ~idSurface( void );

    const idDrawVert &        operator[]( const int index ) const;
    idDrawVert &            operator[]( const int index );
    idSurface &                operator+=( const idSurface &surf );

    int                        GetNumIndexes( void ) const { return indexes.Num(); }
    const int *                GetIndexes( void ) const { return indexes.Ptr(); }
    int                        GetNumVertices( void ) const { return verts.Num(); }
    const idDrawVert *        GetVertices( void ) const { return verts.Ptr(); }
    const int *                GetEdgeIndexes( void ) const { return edgeIndexes.Ptr(); }
    const surfaceEdge_t *    GetEdges( void ) const { return edges.Ptr(); }

    void                    Clear( void );
    void                    SwapTriangles( idSurface &surf );
    void                    TranslateSelf( const idVec3 &translation );
    void                    RotateSelf( const idMat3 &rotation );

                            // splits the surface into a front and back surface, the surface itself stays unchanged
                            // frontOnPlaneEdges and backOnPlaneEdges optionally store the indexes to the edges that lay on the split plane
                            // returns a SIDE_?
    int                        Split( const idPlane &plane, const float epsilon, idSurface **front, idSurface **back, int *frontOnPlaneEdges = NULL, int *backOnPlaneEdges = NULL ) const;
                            // cuts off the part at the back side of the plane, returns true if some part was at the front
                            // if there is nothing at the front the number of points is set to zero
    bool                    ClipInPlace( const idPlane &plane, const float epsilon = ON_EPSILON, const bool keepOn = false );

                            // returns true if each triangle can be reached from any other triangle by a traversal
    bool                    IsConnected( void ) const;
                            // returns true if the surface is closed
    bool                    IsClosed( void ) const;
                            // returns true if the surface is a convex hull
    bool                    IsPolytope( const float epsilon = 0.1f ) const;

    float                    PlaneDistance( const idPlane &plane ) const;
    int                        PlaneSide( const idPlane &plane, const float epsilon = ON_EPSILON ) const;

                            // returns true if the line intersects one of the surface triangles
    bool                    LineIntersection( const idVec3 &start, const idVec3 &end, bool backFaceCull = false ) const;
                            // intersection point is start + dir * scale
    bool                    RayIntersection( const idVec3 &start, const idVec3 &dir, float &scale, bool backFaceCull = false ) const;

protected:
    idList<idDrawVert>        verts;            // vertices
    idList<int>                indexes;        // 3 references to vertices for each triangle
    idList<surfaceEdge_t>    edges;            // edges
    idList<int>                edgeIndexes;    // 3 references to edges for each triangle, may be negative for reversed edge

protected:
    void                    GenerateEdgeIndexes( void );
    int                        FindEdge( int v1, int v2 ) const;
};

/*
====================
idSurface::idSurface
====================
*/
ID_INLINE idSurface::idSurface( void ) {
}

/*
=================
idSurface::idSurface
=================
*/
ID_INLINE idSurface::idSurface( const idDrawVert *verts, const int numVerts, const int *indexes, const int numIndexes ) {
    assert( verts != NULL && indexes != NULL && numVerts > 0 && numIndexes > 0 );
    this->verts.SetNum( numVerts );
    memcpy( this->verts.Ptr(), verts, numVerts * sizeof( verts[0] ) );
    this->indexes.SetNum( numIndexes );
    memcpy( this->indexes.Ptr(), indexes, numIndexes * sizeof( indexes[0] ) );
    GenerateEdgeIndexes();
}

/*
====================
idSurface::idSurface
====================
*/
ID_INLINE idSurface::idSurface( const idSurface &surf ) {
    this->verts = surf.verts;
    this->indexes = surf.indexes;
    this->edges = surf.edges;
    this->edgeIndexes = surf.edgeIndexes;
}

/*
====================
idSurface::~idSurface
====================
*/
ID_INLINE idSurface::~idSurface( void ) {
}

/*
=================
idSurface::operator[]
=================
*/
ID_INLINE const idDrawVert &idSurface::operator[]( const int index ) const {
    return verts[ index ];
};

/*
=================
idSurface::operator[]
=================
*/
ID_INLINE idDrawVert &idSurface::operator[]( const int index ) {
    return verts[ index ];
};

/*
=================
idSurface::operator+=
=================
*/
ID_INLINE idSurface &idSurface::operator+=( const idSurface &surf ) {
    int i, m, n;
    n = verts.Num();
    m = indexes.Num();
    verts.Append( surf.verts );            // merge verts where possible ?
    indexes.Append( surf.indexes );
    for ( i = m; i < indexes.Num(); i++ ) {
        indexes[i] += n;
    }
    GenerateEdgeIndexes();
    return *this;
}

/*
=================
idSurface::Clear
=================
*/
ID_INLINE void idSurface::Clear( void ) {
    verts.Clear();
    indexes.Clear();
    edges.Clear();
    edgeIndexes.Clear();
}

/*
=================
idSurface::SwapTriangles
=================
*/
ID_INLINE void idSurface::SwapTriangles( idSurface &surf ) {
    verts.Swap( surf.verts );
    indexes.Swap( surf.indexes );
    edges.Swap( surf.edges );
    edgeIndexes.Swap( surf.edgeIndexes );
}

/*
=================
idSurface::TranslateSelf
=================
*/
ID_INLINE void idSurface::TranslateSelf( const idVec3 &translation ) {
    for ( int i = 0; i < verts.Num(); i++ ) {
        verts[i].xyz += translation;
    }
}

/*
=================
idSurface::RotateSelf
=================
*/
ID_INLINE void idSurface::RotateSelf( const idMat3 &rotation ) {
    for ( int i = 0; i < verts.Num(); i++ ) {
        verts[i].xyz *= rotation;
        verts[i].normal *= rotation;
        verts[i].tangents[0] *= rotation;
        verts[i].tangents[1] *= rotation;
    }
}

#endif /* !__SURFACE_H__ */