mgcdistpgm3pgm3.cpp

3D Game Engine Design Source Code非常棒

// Magic Software, Inc.
// http://www.magic-software.com
// Copyright (c) 2000, All Rights Reserved
//
// Source code from Magic Software is supplied under the terms of a license
// agreement and may not be copied or disclosed except in accordance with the
// terms of that agreement.  The various license agreements may be found at
// the Magic Software web site.  This file is subject to the license
//
// FREE SOURCE CODE
// http://www.magic-software.com/License/free.pdf

#include "MgcDistLin3Pgm3.h"
#include "MgcDistPgm3Pgm3.h"

//----------------------------------------------------------------------------
MgcReal MgcSqrDistance (const MgcParallelogram3& rkPgm0,
    const MgcParallelogram3& rkPgm1, MgcReal* pfPgm0P0, MgcReal* pfPgm0P1,
    MgcReal* pfPgm1P0, MgcReal* pfPgm1P1)
{
    MgcReal fS, fT, fS0, fT0;  // pgm0 parameters
    MgcReal fU, fV, fU0, fV0;  // pgm1 parameters
    MgcReal fSqrDist, fSqrDist0;
    MgcSegment3 kSeg;

    // compare edges of pgm0 against all of pgm1
    kSeg.Origin() = rkPgm0.Origin();
    kSeg.Direction() = rkPgm0.Edge0();
    fSqrDist = MgcSqrDistance(kSeg,rkPgm1,&fS,&fU,&fV);
    fT = 0.0;

    kSeg.Direction() = rkPgm0.Edge1();
    fSqrDist0 = MgcSqrDistance(kSeg,rkPgm1,&fT0,&fU0,&fV0);
    fS0 = 0.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Origin() = rkPgm0.Origin() + rkPgm0.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkPgm1,&fT0,&fU0,&fV0);
    fS0 = 1.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Origin() = rkPgm0.Origin() + rkPgm0.Edge1();
    kSeg.Direction() = rkPgm0.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkPgm1,&fS0,&fU0,&fV0);
    fT0 = 1.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    // compare edges of pgm1 against all of pgm0
    kSeg.Origin() = rkPgm1.Origin();
    kSeg.Direction() = rkPgm1.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkPgm0,&fU0,&fS0,&fT0);
    fV0 = 0.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Direction() = rkPgm1.Edge1();
    fSqrDist0 = MgcSqrDistance(kSeg,rkPgm0,&fV0,&fS0,&fT0);
    fU0 = 0.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Origin() = rkPgm1.Origin() + rkPgm1.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkPgm0,&fV0,&fS0,&fT0);
    fU0 = 1.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Origin() = rkPgm1.Origin() + rkPgm1.Edge1();
    kSeg.Direction() = rkPgm1.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkPgm0,&fU0,&fS0,&fT0);
    fV0 = 1.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    if ( pfPgm0P0 )
        *pfPgm0P0 = fS;

    if ( pfPgm0P1 )
        *pfPgm0P1 = fT;

    if ( pfPgm1P0 )
        *pfPgm1P0 = fU;

    if ( pfPgm1P1 )
        *pfPgm1P1 = fV;

    return MgcMath::Abs(fSqrDist);
}
//----------------------------------------------------------------------------
MgcReal MgcDistance (const MgcParallelogram3& rkPgm0,
    const MgcParallelogram3& rkPgm1, MgcReal* pfPgm0P0, MgcReal* pfPgm0P1,
    MgcReal* pfPgm1P0, MgcReal* pfPgm1P1)
{
    return MgcMath::Sqrt(MgcSqrDistance(rkPgm0,rkPgm1,pfPgm0P0,pfPgm0P1,
        pfPgm1P0,pfPgm1P1));
}
//----------------------------------------------------------------------------