mgcparametricsurface.h

《3D游戏引擎设计》的源码

// 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

#ifndef MGCPARAMETRICSURFACE_H
#define MGCPARAMETRICSURFACE_H

#include "MgcSurface.h"
#include "MgcVector3.h"


class MgcParametricSurface : public MgcSurface
{
public:
    // position and derivatives up to second order
    virtual MgcVector3 GetPosition (MgcReal fU, MgcReal fV) const = 0;
    virtual MgcVector3 GetDerivativeU (MgcReal fU, MgcReal fV) const = 0;
    virtual MgcVector3 GetDerivativeV (MgcReal fU, MgcReal fV) const = 0;
    virtual MgcVector3 GetDerivativeUU (MgcReal fU, MgcReal fV) const = 0;
    virtual MgcVector3 GetDerivativeUV (MgcReal fU, MgcReal fV) const = 0;
    virtual MgcVector3 GetDerivativeVV (MgcReal fU, MgcReal fV) const = 0;

    // coordinate frame values
    MgcVector3 GetTangent0 (MgcReal fU, MgcReal fV) const;
    MgcVector3 GetTangent1 (MgcReal fU, MgcReal fV) const;
    MgcVector3 GetNormal (MgcReal fU, MgcReal fV) const;
    void GetFrame (MgcReal fU, MgcReal fV, MgcVector3& kPosition,
        MgcVector3& kTangent0, MgcVector3& kTangent1,
        MgcVector3& kNormal) const;

    // differential geometric quantities
    void ComputePrincipalCurvatureInfo (MgcReal fU, MgcReal fV,
        MgcReal& rfCurv0, MgcReal& rfCurv1, MgcVector3& rkDir0,
        MgcVector3& rkDir1);
};

#endif