wmldistlin3rct3.cpp

3D Game Engine Design Source Code非常棒

                {
                    // min on face s=0 or t=0 or r=1
                    kSegPgm.Origin() = rkRct.Origin();
                    kSegPgm.Direction() = rkRct.Edge1();
                    fSqrDist = SqrDistance(rkSeg,kSegPgm,&fR,&fT);
                    fS = (Real)0.0;
                    kSegPgm.Origin() = rkRct.Origin();
                    kSegPgm.Direction() = rkRct.Edge0();
                    fSqrDist0 = SqrDistance(rkSeg,kSegPgm,&fR0,&fS0);
                    fT0 = (Real)0.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                    kPt = rkSeg.Origin()+rkSeg.Direction();
                    fSqrDist0 = SqrDistance(kPt,rkRct,&fS0,&fT0);
                    fR0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                }
                else if ( fT <= (Real)1.0 )  // region 5p
                {
                    // min on face s=0 or r=1
                    kSegPgm.Origin() = rkRct.Origin();
                    kSegPgm.Direction() = rkRct.Edge1();
                    fSqrDist = SqrDistance(rkSeg,kSegPgm,&fR,&fT);
                    fS = (Real)0.0;
                    fSqrDist0 = SqrDistance(rkSeg.Origin(),rkRct,&fS0,&fT0);
                    kPt = rkSeg.Origin()+rkSeg.Direction();
                    fSqrDist0 = SqrDistance(kPt,rkRct,&fS0,&fT0);
                    fR0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                }
                else  // region 4p
                {
                    // min on face s=0 or t=1 or r=1
                    kSegPgm.Origin() = rkRct.Origin();
                    kSegPgm.Direction() = rkRct.Edge1();
                    fSqrDist = SqrDistance(rkSeg,kSegPgm,&fR,&fT);
                    fS = (Real)0.0;
                    kSegPgm.Origin() = rkRct.Origin()+rkRct.Edge1();
                    kSegPgm.Direction() = rkRct.Edge0();
                    fSqrDist0 = SqrDistance(rkSeg,kSegPgm,&fR0,&fS0);
                    fT0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                    kPt = rkSeg.Origin()+rkSeg.Direction();
                    fSqrDist0 = SqrDistance(kPt,rkRct,&fS0,&fT0);
                    fR0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                }
            }
            else if ( fS <= (Real)1.0 )
            {
                if ( fT < (Real)0.0 )  // region 7p
                {
                    // min on face t=0 or r=1
                    kSegPgm.Origin() = rkRct.Origin();
                    kSegPgm.Direction() = rkRct.Edge0();
                    fSqrDist = SqrDistance(rkSeg,kSegPgm,&fR,&fS);
                    fT = (Real)0.0;
                    kPt = rkSeg.Origin()+rkSeg.Direction();
                    fSqrDist0 = SqrDistance(kPt,rkRct,&fS0,&fT0);
                    fR0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                }
                else if ( fT <= (Real)1.0 )  // region 0p
                {
                    // min on face r=1
                    kPt = rkSeg.Origin()+rkSeg.Direction();
                    fSqrDist = SqrDistance(kPt,rkRct,&fS,&fT);
                    fR = (Real)1.0;
                }
                else  // region 3p
                {
                    // min on face t=1 or r=1
                    kSegPgm.Origin() = rkRct.Origin()+rkRct.Edge1();
                    kSegPgm.Direction() = rkRct.Edge0();
                    fSqrDist = SqrDistance(rkSeg,kSegPgm,&fR,&fS);
                    fT = (Real)1.0;
                    kPt = rkSeg.Origin()+rkSeg.Direction();
                    fSqrDist0 = SqrDistance(kPt,rkRct,&fS0,&fT0);
                    fR0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                }
            }
            else
            {
                if ( fT < (Real)0.0 )  // region 8p
                {
                    // min on face s=1 or t=0 or r=1
                    kSegPgm.Origin() = rkRct.Origin()+rkRct.Edge0();
                    kSegPgm.Direction() = rkRct.Edge1();
                    fSqrDist = SqrDistance(rkSeg,kSegPgm,&fR,&fT);
                    fS = (Real)1.0;
                    kSegPgm.Origin() = rkRct.Origin();
                    kSegPgm.Direction() = rkRct.Edge0();
                    fSqrDist0 = SqrDistance(rkSeg,kSegPgm,&fR0,&fS0);
                    fT0 = (Real)0.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                    kPt = rkSeg.Origin()+rkSeg.Direction();
                    fSqrDist0 = SqrDistance(kPt,rkRct,&fS0,&fT0);
                    fR0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                }
                else if ( fT <= (Real)1.0 )  // region 1p
                {
                    // min on face s=1 or r=1
                    kSegPgm.Origin() = rkRct.Origin()+rkRct.Edge0();
                    kSegPgm.Direction() = rkRct.Edge1();
                    fSqrDist = SqrDistance(rkSeg,kSegPgm,&fR,&fT);
                    fS = (Real)1.0;
                    kPt = rkSeg.Origin()+rkSeg.Direction();
                    fSqrDist0 = SqrDistance(kPt,rkRct,&fS0,&fT0);
                    fR0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                }
                else  // region 2p
                {
                    // min on face s=1 or t=1 or r=1
                    kSegPgm.Origin() = rkRct.Origin()+rkRct.Edge0();
                    kSegPgm.Direction() = rkRct.Edge1();
                    fSqrDist = SqrDistance(rkSeg,kSegPgm,&fR,&fT);
                    fS = (Real)1.0;
                    kSegPgm.Origin() = rkRct.Origin()+rkRct.Edge1();
                    kSegPgm.Direction() = rkRct.Edge0();
                    fSqrDist0 = SqrDistance(rkSeg,kSegPgm,&fR0,&fS0);
                    fT0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                    kPt = rkSeg.Origin()+rkSeg.Direction();
                    fSqrDist0 = SqrDistance(kPt,rkRct,&fS0,&fT0);
                    fR0 = (Real)1.0;
                    if ( fSqrDist0 < fSqrDist )
                    {
                        fSqrDist = fSqrDist0;
                        fR = fR0;
                        fS = fS0;
                        fT = fT0;
                    }
                }
            }
        }
    }
    else
    {
        // segment and rectangle are parallel
        kSegPgm.Origin() = rkRct.Origin();
        kSegPgm.Direction() = rkRct.Edge0();
        fSqrDist = SqrDistance(rkSeg,kSegPgm,&fR,&fS);
        fT = (Real)0.0;

        kSegPgm.Direction() = rkRct.Edge1();
        fSqrDist0 = SqrDistance(rkSeg,kSegPgm,&fR0,&fT0);
        fS0 = (Real)0.0;
        if ( fSqrDist0 < fSqrDist )
        {
            fSqrDist = fSqrDist0;
            fR = fR0;
            fS = fS0;
            fT = fT0;
        }

        kSegPgm.Origin() = rkRct.Origin()+rkRct.Edge1();
        kSegPgm.Direction() = rkRct.Edge0();
        fSqrDist0 = SqrDistance(rkSeg,kSegPgm,&fR0,&fS0);
        fT0 = (Real)1.0;
        if ( fSqrDist0 < fSqrDist )
        {
            fSqrDist = fSqrDist0;
            fR = fR0;
            fS = fS0;
            fT = fT0;
        }

        kSegPgm.Origin() = rkRct.Origin()+rkRct.Edge0();
        kSegPgm.Direction() = rkRct.Edge1();
        fSqrDist0 = SqrDistance(rkSeg,kSegPgm,&fR0,&fT0);
        fS0 = (Real)1.0;
        if ( fSqrDist0 < fSqrDist )
        {
            fSqrDist = fSqrDist0;
            fR = fR0;
            fS = fS0;
            fT = fT0;
        }

        fSqrDist0 = SqrDistance(rkSeg.Origin(),rkRct,&fS0,&fT0);
        fR0 = (Real)0.0;
        if ( fSqrDist0 < fSqrDist )
        {
            fSqrDist = fSqrDist0;
            fR = fR0;
            fS = fS0;
            fT = fT0;
        }

        kPt = rkSeg.Origin()+rkSeg.Direction();
        fSqrDist0 = SqrDistance(kPt,rkRct,&fS0,&fT0);
        fR0 = (Real)1.0;
        if ( fSqrDist0 < fSqrDist )
        {
            fSqrDist = fSqrDist0;
            fR = fR0;
            fS = fS0;
            fT = fT0;
        }
    }

    if ( pfSegP )
        *pfSegP = fR;

    if ( pfRctP0 )
        *pfRctP0 = fS;

    if ( pfRctP1 )
        *pfRctP1 = fT;

    return Math<Real>::FAbs(fSqrDist);
}
//----------------------------------------------------------------------------
template <class Real>
Real Wml::Distance (const Line3<Real>& rkLine, const Rectangle3<Real>& rkRct,
    Real* pfLinP, Real* pfRctP0, Real* pfRctP1)
{
    return Math<Real>::Sqrt(SqrDistance(rkLine,rkRct,pfLinP,pfRctP0,pfRctP1));
}
//----------------------------------------------------------------------------
template <class Real>
Real Wml::Distance (const Ray3<Real>& rkRay, const Rectangle3<Real>& rkRct,
    Real* pfRayP, Real* pfRctP0, Real* pfRctP1)
{
    return Math<Real>::Sqrt(SqrDistance(rkRay,rkRct,pfRayP,pfRctP0,pfRctP1));
}
//----------------------------------------------------------------------------
template <class Real>
Real Wml::Distance (const Segment3<Real>& rkSeg,
    const Rectangle3<Real>& rkRct, Real* pfSegP, Real* pfRctP0, Real* pfRctP1)
{
    return Math<Real>::Sqrt(SqrDistance(rkSeg,rkRct,pfSegP,pfRctP0,pfRctP1));
}
//----------------------------------------------------------------------------

//----------------------------------------------------------------------------
// explicit instantiation
//----------------------------------------------------------------------------
namespace Wml
{
template WML_ITEM float SqrDistance<float> (const Line3<float>&,
    const Rectangle3<float>&, float*, float*, float*);
template WML_ITEM float SqrDistance<float> (const Ray3<float>&,
    const Rectangle3<float>&, float*, float*, float*);
template WML_ITEM float SqrDistance<float> (const Segment3<float>&,
    const Rectangle3<float>&, float*, float*, float*);
template WML_ITEM float Distance<float> (const Line3<float>&,
    const Rectangle3<float>&, float*, float*, float*);
template WML_ITEM float Distance<float> (const Ray3<float>&,
    const Rectangle3<float>&, float*, float*, float*);
template WML_ITEM float Distance<float> (const Segment3<float>&,
    const Rectangle3<float>&, float*, float*, float*);

template WML_ITEM double SqrDistance<double> (const Line3<double>&,
    const Rectangle3<double>&, double*, double*, double*);
template WML_ITEM double SqrDistance<double> (const Ray3<double>&,
    const Rectangle3<double>&, double*, double*, double*);
template WML_ITEM double SqrDistance<double> (const Segment3<double>&,
    const Rectangle3<double>&, double*, double*, double*);
template WML_ITEM double Distance<double> (const Line3<double>&,
    const Rectangle3<double>&, double*, double*, double*);
template WML_ITEM double Distance<double> (const Ray3<double>&,
    const Rectangle3<double>&, double*, double*, double*);
template WML_ITEM double Distance<double> (const Segment3<double>&,
    const Rectangle3<double>&, double*, double*, double*);
}
//----------------------------------------------------------------------------