mgcintrplnsphr.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 "MgcIntrPlnSphr.h"

//----------------------------------------------------------------------------
bool MgcTestIntersection (const MgcPlane& rkPlane, const MgcSphere& rkSphere,
    bool bUnitNormal)
{
    MgcVector3 kNormal = rkPlane.Normal();
    MgcReal fConstant = rkPlane.Constant();
    if ( !bUnitNormal )
    {
        MgcReal fLength = kNormal.Unitize();
        fConstant /= fLength;
    }

    MgcReal fPseudoDistance = kNormal.Dot(rkSphere.Center()) - fConstant;
    return MgcMath::Abs(fPseudoDistance) <= rkSphere.Radius();
}
//----------------------------------------------------------------------------
bool MgcCulled (const MgcPlane& rkPlane, const MgcSphere& rkSphere,
    bool bUnitNormal)
{
    MgcVector3 kNormal = rkPlane.Normal();
    MgcReal fConstant = rkPlane.Constant();
    if ( !bUnitNormal )
    {
        MgcReal fLength = kNormal.Unitize();
        fConstant /= fLength;
    }

    MgcReal fTmp = kNormal.Dot(rkSphere.Center()) - fConstant;
    return fTmp <= -rkSphere.Radius();
}
//----------------------------------------------------------------------------