mgcintrplnbox3.cpp

来自「《3D游戏引擎设计》的源码」· C++ 代码 · 共 48 行

// 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 "MgcIntrPlnBox3.h"

//----------------------------------------------------------------------------
bool MgcTestIntersection (const MgcPlane& rkPlane, const MgcBox3& rkBox)
{
    MgcReal fTmp[3] =
    {
        rkBox.Extent(0)*(rkPlane.Normal().Dot(rkBox.Axis(0))),
        rkBox.Extent(1)*(rkPlane.Normal().Dot(rkBox.Axis(1))),
        rkBox.Extent(2)*(rkPlane.Normal().Dot(rkBox.Axis(2)))
    };

    MgcReal fRadius = MgcMath::Abs(fTmp[0]) + MgcMath::Abs(fTmp[1]) +
        MgcMath::Abs(fTmp[2]);

    MgcReal fPseudoDistance = rkPlane.DistanceTo(rkBox.Center());
    return MgcMath::Abs(fPseudoDistance) <= fRadius;
}
//----------------------------------------------------------------------------
bool MgcCulled (const MgcPlane& rkPlane, const MgcBox3& rkBox)
{
    MgcReal fTmp[3] =
    {
        rkBox.Extent(0)*(rkPlane.Normal().Dot(rkBox.Axis(0))),
        rkBox.Extent(1)*(rkPlane.Normal().Dot(rkBox.Axis(1))),
        rkBox.Extent(2)*(rkPlane.Normal().Dot(rkBox.Axis(2)))
    };

    MgcReal fRadius = MgcMath::Abs(fTmp[0]) + MgcMath::Abs(fTmp[1]) +
        MgcMath::Abs(fTmp[2]);

    MgcReal fPseudoDistance = rkPlane.DistanceTo(rkBox.Center());
    return fPseudoDistance <= -fRadius;
}
//----------------------------------------------------------------------------