mgcdistrct3rct3.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 "MgcDistLin3Rct3.h"
#include "MgcDistRct3Rct3.h"

//----------------------------------------------------------------------------
MgcReal MgcSqrDistance (const MgcRectangle3& rkRct0,
    const MgcRectangle3& rkRct1, MgcReal* pfRct0P0, MgcReal* pfRct0P1,
    MgcReal* pfRct1P0, MgcReal* pfRct1P1)
{
    MgcReal fS, fT, fS0, fT0;  // rct0 parameters
    MgcReal fU, fV, fU0, fV0;  // rct1 parameters
    MgcReal fSqrDist, fSqrDist0;
    MgcSegment3 kSeg;

    // compare edges of rct0 against all of rct1
    kSeg.Origin() = rkRct0.Origin();
    kSeg.Direction() = rkRct0.Edge0();
    fSqrDist = MgcSqrDistance(kSeg,rkRct1,&fS,&fU,&fV);
    fT = 0.0;

    kSeg.Direction() = rkRct0.Edge1();
    fSqrDist0 = MgcSqrDistance(kSeg,rkRct1,&fT0,&fU0,&fV0);
    fS0 = 0.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Origin() = rkRct0.Origin() + rkRct0.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkRct1,&fT0,&fU0,&fV0);
    fS0 = 1.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Origin() = rkRct0.Origin() + rkRct0.Edge1();
    kSeg.Direction() = rkRct0.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkRct1,&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() = rkRct1.Origin();
    kSeg.Direction() = rkRct1.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkRct0,&fU0,&fS0,&fT0);
    fV0 = 0.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Direction() = rkRct1.Edge1();
    fSqrDist0 = MgcSqrDistance(kSeg,rkRct0,&fV0,&fS0,&fT0);
    fU0 = 0.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Origin() = rkRct1.Origin() + rkRct1.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkRct0,&fV0,&fS0,&fT0);
    fU0 = 1.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    kSeg.Origin() = rkRct1.Origin() + rkRct1.Edge1();
    kSeg.Direction() = rkRct1.Edge0();
    fSqrDist0 = MgcSqrDistance(kSeg,rkRct0,&fU0,&fS0,&fT0);
    fV0 = 1.0;
    if ( fSqrDist0 < fSqrDist )
    {
        fSqrDist = fSqrDist0;
        fS = fS0;
        fT = fT0;
        fU = fU0;
        fV = fV0;
    }

    if ( pfRct0P0 )
        *pfRct0P0 = fS;

    if ( pfRct0P1 )
        *pfRct0P1 = fT;

    if ( pfRct1P0 )
        *pfRct1P0 = fU;

    if ( pfRct1P1 )
        *pfRct1P1 = fV;

    return MgcMath::Abs(fSqrDist);
}
//----------------------------------------------------------------------------
MgcReal MgcDistance (const MgcRectangle3& rkRct0, const MgcRectangle3& rkRct1,
    MgcReal* pfRct0P0, MgcReal* pfRct0P1, MgcReal* pfRct1P0,
    MgcReal* pfRct1P1)
{
    return MgcMath::Sqrt(MgcSqrDistance(rkRct0,rkRct1,pfRct0P0,pfRct0P1,
        pfRct1P0,pfRct1P1));
}
//----------------------------------------------------------------------------