gravitation.h

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/* This file is part of StepCore library.
   Copyright (C) 2007 Vladimir Kuznetsov <ks.vladimir@gmail.com>

   StepCore library is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   StepCore library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with StepCore; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef STEPCORE_GRAVITATION_H
#define STEPCORE_GRAVITATION_H

#include "world.h"
#include "object.h"
#include "constants.h"

namespace StepCore
{

class GravitationForce;
class WeightForce;

class GravitationForceErrors: public ObjectErrors
{
    STEPCORE_OBJECT(GravitationForceErrors)

public:
    GravitationForceErrors(Item* owner = NULL)
        : ObjectErrors(owner), _gravitationConstVariance(0) {}

    GravitationForce* gravitationForce() const;

    double gravitationConstVariance() const { return _gravitationConstVariance; }
    void   setGravitationConstVariance(double gravitationConstVariance) {
        _gravitationConstVariance = gravitationConstVariance; }

protected:
    double _gravitationConstVariance;
    friend class GravitationForce;
};

class GravitationForce: public Item, public Force
{
    STEPCORE_OBJECT(GravitationForce)

public:
    GravitationForce(double gravitationConst = Constants::Gravitational);

    void calcForce(bool calcVariances);

    double gravitationConst() const { return _gravitationConst; }
    void   setGravitationConst(double gravitationConst) { _gravitationConst = gravitationConst; }

    GravitationForceErrors* gravitationForceErrors() {
        return static_cast<GravitationForceErrors*>(objectErrors()); }

protected:
    ObjectErrors* createObjectErrors() { return new GravitationForceErrors(this); }

    double _gravitationConst;
};

class WeightForceErrors: public ObjectErrors
{
    STEPCORE_OBJECT(WeightForceErrors)

public:
    WeightForceErrors(Item* owner = NULL)
        : ObjectErrors(owner), _weightConstVariance(0) {}

    WeightForce* weightForce() const;

    double weightConstVariance() const { return _weightConstVariance; }
    void   setWeightConstVariance(double weightConstVariance) {
        _weightConstVariance = weightConstVariance; }

protected:
    double _weightConstVariance;
    friend class WeightForce;
};

class WeightForce: public Item, public Force
{
    STEPCORE_OBJECT(WeightForce)

public:
    WeightForce(double weightConst = Constants::WeightAccel);

    void calcForce(bool calcVariances);

    double weightConst() const { return _weightConst; }
    void   setWeightConst(double weightConst) { _weightConst = weightConst; }

    WeightForceErrors* weightForceErrors() {
        return static_cast<WeightForceErrors*>(objectErrors()); }

protected:
    ObjectErrors* createObjectErrors() { return new WeightForceErrors(this); }

    double _weightConst;
};

} // namespace StepCore

#endif