Comet.hpp

/*
 * Stellarium
 * Copyright (C) 2010 Bogdan Marinov
 * Copyright (C) 2014 Georg Zotti (orbit fix, tails, speedup)
 *
 * This program 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.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA  02110-1335, USA.
 */
 
#ifndef _COMET_HPP_
#define _COMET_HPP_

#include "Planet.hpp"

class Comet : public Planet
{
public:
    friend class SolarSystem;               // Solar System initializes static constants.
    Comet(const QString& englishName,
          int flagLighting,
          double radius,
          double oblateness,
          Vec3f halocolor,
          float albedo,
          const QString& texMapName,
          posFuncType _coordFunc,
          void* userDataPtr,
          OsculatingFunctType *osculatingFunc,
          bool closeOrbit,
          bool hidden,
          const QString &pTypeStr,
          float dustTailWidthFact=1.5f,
          float dustTailLengthFact=0.4f,
          float dustTailBrightnessFact=1.5f
    );

    virtual ~Comet();

    //Inherited from StelObject via Planet
    //  - Size <- Size of what?
    virtual QString getInfoString(const StelCore *core, const InfoStringGroup &flags) const;
    virtual QVariantMap getInfoMap(const StelCore *core) const;
    //The Comet class inherits the "Planet" type because the SolarSystem class
    //was not designed to handle different types of objects.
    //virtual QString getType() const {return "Comet";}
    virtual float getVMagnitude(const StelCore* core) const;
    virtual void translateName(const StelTranslator& trans);
    virtual QString getEnglishName(void) const {return englishName;}
    virtual QString getNameI18n(void) const {return nameI18;}

    void setAbsoluteMagnitudeAndSlope(const double magnitude, const double slope);

    void setSemiMajorAxis(const double value);

    virtual double getSiderealPeriod() const;

    virtual void draw(StelCore* core, float maxMagLabels, const QFont& planetNameFont);

    // re-implementation of Planet's update() to prepare tails (extinction etc). @param deltaTime: ms (since last call)
    virtual void update(int deltaTime);

private:
    Vec2f getComaDiameterAndTailLengthAU();
    void drawTail(StelCore* core, StelProjector::ModelViewTranformP transfo, bool gas);
    void drawComa(StelCore* core, StelProjector::ModelViewTranformP transfo);

    void computeComa(const float diameter);

    void computeParabola(const float parameter, const float topradius, const float zshift, QVector<Vec3d>& vertexArr, QVector<float>& texCoordArr, QVector<unsigned short>& indices, const float xOffset=0.0f);

    double absoluteMagnitude;
    double slopeParameter;
    double semiMajorAxis;
    bool isCometFragment;
    bool nameIsProvisionalDesignation;

    //GZ Tail additions
    Vec2f tailFactors; // result of latest call to getComaDiameterAndTailLengthAU(); Results cached here for infostring. [0]=Coma diameter, [1] gas tail length.
    bool tailActive;        
    bool tailBright;        
    double deltaJDEtail;            
    double lastJDEtail;             
    Mat4d gasTailRot;       
    Mat4d dustTailRot;      
    float dustTailWidthFactor;      
    float dustTailLengthFactor;     
    float dustTailBrightnessFactor; 
    QVector<double> comaVertexArr;
    QVector<float> comaTexCoordArr; //  --> 2014-08: could also be declared static, but it is filled by StelPainter...

    // These are to avoid having index arrays for each comet when all are equal.
    static bool createTailIndices;
    static bool createTailTextureCoords;

    QVector<Vec3d> gastailVertexArr;  // computed frequently, describes parabolic shape (along z axis) of gas tail.
    QVector<Vec3d> dusttailVertexArr; // computed frequently, describes parabolic shape (along z axis) of dust tail.
    QVector<Vec3f> gastailColorArr;    // NEW computed for every 5 mins, modulates gas tail brightness for extinction
    QVector<Vec3f> dusttailColorArr;   // NEW computed for every 5 mins, modulates dust tail brightness for extinction
    static QVector<float> tailTexCoordArr; // computed only once for all comets!
    static QVector<unsigned short> tailIndices; // computed only once for all comets!
    static StelTextureSP comaTexture;
    static StelTextureSP tailTexture;      // it seems not really necessary to have different textures. gas tail is just painted blue.
};

#endif //_COMET_HPP_