Atmosphere.hpp

/*
 * Stellarium
 * Copyright (C) 2003 Fabien Chereau
 * Copyright (C) 2012 Timothy Reaves
 *
 * 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 _ATMOSTPHERE_HPP_
#define _ATMOSTPHERE_HPP_

#include "Skylight.hpp"
#include "VecMath.hpp"

#include "Skybright.hpp"
#include "StelFader.hpp"

#include <QOpenGLBuffer>

class StelProjector;
class StelToneReproducer;
class StelCore;

class Atmosphere
{
public:
    Atmosphere();
    virtual ~Atmosphere();
    
    void computeColor(double JD, Vec3d _sunPos, Vec3d moonPos, float moonPhase, StelCore* core,
        float latitude = 45.f, float altitude = 200.f,
        float temperature = 15.f, float relativeHumidity = 40.f);
    void draw(StelCore* core);
    void update(double deltaTime) {fader.update((int)(deltaTime*1000));}

    void setFadeDuration(float duration) {fader.setDuration((int)(duration*1000.f));}
    float getFadeDuration() {return (float)fader.getDuration()/1000.f;}

    void setFlagShow(bool b){fader = b;}
    bool getFlagShow() const {return fader;}

    float getRealDisplayIntensityFactor() const {return fader.getInterstate()*eclipseFactor;}

    // lets you know how far faded in or out the atmosphere is (0..1)
    float getFadeIntensity() const {return fader.getInterstate();}

    float getAverageLuminance() const {return averageLuminance;}

    void setAverageLuminance(float overrideLum);
    void setLightPollutionLuminance(float f) { lightPollutionLuminance = f; }
    float getLightPollutionLuminance() const { return lightPollutionLuminance; }

private:
    Vec4i viewport;
    Skylight sky;
    Skybright skyb;
    int skyResolutionY,skyResolutionX;

    Vec2f* posGrid;
    QOpenGLBuffer posGridBuffer;
    QOpenGLBuffer indicesBuffer;
    Vec4f* colorGrid;
    QOpenGLBuffer colorGridBuffer;

    float averageLuminance;
    bool overrideAverageLuminance; // if true, don't compute but keep value set via setAverageLuminance(float)
    float eclipseFactor;
    LinearFader fader;
    float lightPollutionLuminance;

    class QOpenGLShaderProgram* atmoShaderProgram;
    struct {
        int alphaWaOverAlphaDa;
        int oneOverGamma;
        int term2TimesOneOverMaxdLpOneOverGamma;
        int brightnessScale;
        int sunPos;
        int term_x, Ax, Bx, Cx, Dx, Ex;
        int term_y, Ay, By, Cy, Dy, Ey;
        int projectionMatrix;
        int skyVertex;
        int skyColor;
    } shaderAttribLocations;
};

#endif // _ATMOSTPHERE_HPP_