mgccontcylinder.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 "MgcContCylinder.h"
#include "MgcDistVec3Lin3.h"
#include "MgcLineFit.h"

//----------------------------------------------------------------------------
MgcCylinder MgcContCylinder (int iQuantity, const MgcVector3* akPoint)
{
    MgcCylinder kCylinder;

    MgcLine3 kLine;
    MgcOrthogonalLineFit(iQuantity,akPoint,kLine.Origin(),kLine.Direction());

    MgcReal fMaxRadiusSqr = 0.0;
    int i;
    for (i = 0; i < iQuantity; i++)
    {
        MgcReal fRadiusSqr = MgcSqrDistance(akPoint[i],kLine);
        if ( fRadiusSqr > fMaxRadiusSqr )
            fMaxRadiusSqr = fRadiusSqr;
    }

    MgcVector3 kDiff = akPoint[0] - kLine.Origin();
    MgcReal fWMin = kLine.Direction().Dot(kDiff), fWMax = fWMin;
    for (i = 1; i < iQuantity; i++)
    {
        kDiff = akPoint[i] - kLine.Origin();
        MgcReal fW = kLine.Direction().Dot(kDiff);
        if ( fW < fWMin )
            fWMin = fW;
        else if ( fW > fWMax )
            fWMax = fW;
    }

    kCylinder.Center() = kLine.Origin() +
        (0.5*(fWMax+fWMin))*kLine.Direction();
    kCylinder.Direction() = kLine.Direction();
    kCylinder.Radius() = MgcMath::Sqrt(fMaxRadiusSqr);
    kCylinder.Height() = fWMax - fWMin;

    return kCylinder;
}
//----------------------------------------------------------------------------