StelSkyDrawer.hpp

/*
 * Stellarium
 * Copyright (C) 2007 Fabien Chereau
 *
 * 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 _STELSKYDRAWER_HPP_
#define _STELSKYDRAWER_HPP_

#include "RefractionExtinction.hpp"
#include "StelTextureTypes.hpp"
#include "StelProjectorType.hpp"
#include "VecMath.hpp"

#include <QObject>

class StelToneReproducer;
class StelCore;
class StelPainter;

struct RCMag
{
    float radius;
    float luminance;
};

class StelSkyDrawer : public QObject
{
    Q_OBJECT
public:

    StelSkyDrawer(StelCore* core);
    ~StelSkyDrawer();

    void init();

    void update(double deltaTime);

    void preDrawPointSource(StelPainter* p);

    void postDrawPointSource(StelPainter* sPainter);

    bool drawPointSource(StelPainter* sPainter, const Vec3f& v, const RCMag &rcMag, unsigned int bV, bool checkInScreen=false)
    {
        return drawPointSource(sPainter, v, rcMag, colorTable[bV], checkInScreen);
    }

    bool drawPointSource(StelPainter* sPainter, const Vec3f& v, const RCMag &rcMag, const Vec3f& bcolor, bool checkInScreen=false);

    void postDrawSky3dModel(StelPainter* p, const Vec3f& v, float illuminatedArea, float mag, const Vec3f& color = Vec3f(1.f,1.f,1.f));

    bool computeRCMag(float mag, RCMag*) const;

    void reportLuminanceInFov(float lum, bool fastAdaptation=false);

    void preDraw();

    static float surfacebrightnessToLuminance(float sb);
    static float luminanceToSurfacebrightness(float lum);

    static inline float indexToBV(unsigned char bV)
    {
        return (float)bV*(4.f/127.f)-0.5f;
    }

    static inline const Vec3f& indexToColor(unsigned char bV)
    {
        return colorTable[bV];
    }

public slots:
    void setRelativeStarScale(double b=1.0) {starRelativeScale=b;}
    float getRelativeStarScale() const {return starRelativeScale;}

    void setAbsoluteStarScale(double b=1.0) {starAbsoluteScaleF=b;}
    float getAbsoluteStarScale() const {return starAbsoluteScaleF;}

    void setTwinkleAmount(double b) {twinkleAmount=b;}
    float getTwinkleAmount() const {return twinkleAmount;}

    void setFlagTwinkle(bool b) {flagStarTwinkle=b;}
    bool getFlagTwinkle() const {return flagStarTwinkle;}

    void setBortleScaleIndex(int index);
    int getBortleScaleIndex() const {return bortleScaleIndex;}

    float getLimitMagnitude() const {return limitMagnitude;}

    // FIXME: Exposed to scripts - make sure it synchs with the GUI. --BM
    void setFlagStarMagnitudeLimit(bool b) {flagStarMagnitudeLimit = b;}
    // FIXME: Exposed to scripts - make sure it synchs with the GUI. --BM
    void setFlagNebulaMagnitudeLimit(bool b) {flagNebulaMagnitudeLimit = b;}
    bool getFlagStarMagnitudeLimit() const {return flagStarMagnitudeLimit;}
    bool getFlagNebulaMagnitudeLimit() const {return flagNebulaMagnitudeLimit;}

    float getCustomStarMagnitudeLimit() const {return customStarMagLimit;}
    void setCustomStarMagnitudeLimit(double limit) {customStarMagLimit=limit;}
    float getCustomNebulaMagnitudeLimit() const {return customNebulaMagLimit;}
    void setCustomNebulaMagnitudeLimit(double limit) {customNebulaMagLimit=limit;}

    float getLimitLuminance() const {return limitLuminance;}

    void setFlagLuminanceAdaptation(bool b) {flagLuminanceAdaptation=b;}
    bool getFlagLuminanceAdaptation() const {return flagLuminanceAdaptation;}

    void setFlagHasAtmosphere(bool b) {flagHasAtmosphere=b;}
    bool getFlagHasAtmosphere() const {return flagHasAtmosphere;}

    void setExtinctionCoefficient(double extCoeff) {extinction.setExtinctionCoefficient(extCoeff);}
    double getExtinctionCoefficient() const {return extinction.getExtinctionCoefficient();}
    void setAtmosphereTemperature(double celsius) {refraction.setTemperature(celsius);}
    double getAtmosphereTemperature() const {return refraction.getTemperature();}
    void setAtmospherePressure(double mbar) {refraction.setPressure(mbar);}
    double getAtmospherePressure() const {return refraction.getPressure();}

    const Extinction& getExtinction() const {return extinction;}
    const Refraction& getRefraction() const {return refraction;}

    float getBig3dModelHaloRadius() const {return big3dModelHaloRadius;}
    void setBig3dModelHaloRadius(float r) {big3dModelHaloRadius=r;}
    
private:
    // Debug
    float reverseComputeRCMag(float rmag) const;

    float computeLimitMagnitude() const;

    float computeLimitLuminance() const;

    float getMaxAdaptFov(void) const {return maxAdaptFov;}
    void setMaxAdaptFov(float fov) {maxAdaptFov = (fov < 60.f) ? 60.f : fov;}

    float getMinAdaptFov(void) const {return minAdaptFov;}
    void setMinAdaptFov(float fov) {minAdaptFov = (fov > 60.f) ? 60.f : fov;}

    void setInputScale(float in) {inScale = in;}
    float getInputScale() const {return inScale;}

    inline float pointSourceMagToLuminance(float mag) const {return std::exp(pointSourceMagToLnLuminance(mag));}

    float pointSourceLuminanceToMag(float lum);

    float pointSourceMagToLnLuminance(float mag) const;

    float findWorldLumForMag(float mag, float targetRadius);

    StelCore* core;
    StelToneReproducer* eye;

    Extinction extinction;
    Refraction refraction;

    float maxAdaptFov, minAdaptFov, lnfovFactor;
    bool flagStarTwinkle;
    float twinkleAmount;

    bool flagHasAtmosphere;

    bool flagStarMagnitudeLimit;
    bool flagNebulaMagnitudeLimit;

    float starRelativeScale;
    float starAbsoluteScaleF;

    float starLinearScale;  // optimization variable

    float limitMagnitude;

    float limitLuminance;

    float customStarMagLimit;
    float customNebulaMagLimit;

    StelTextureSP texHalo;

    void initColorTableFromConfigFile(class QSettings* conf);

    static Vec3f colorTable[128];

    int bortleScaleIndex;

    float inScale;

    // Variables used for GL optimization when displaying point sources
    struct StarVertex {
        Vec2f pos;
        unsigned char color[4];
    };
    
    StarVertex* vertexArray;

    unsigned char* textureCoordArray;
    
    class QOpenGLShaderProgram* starShaderProgram;
    struct StarShaderVars {
        int projectionMatrix;
        int texCoord;
        int pos;
        int color;
        int texture;
    };
    StarShaderVars starShaderVars;
    
    unsigned int nbPointSources;
    unsigned int maxPointSources;

    float maxLum;
    float oldLum;

    StelTextureSP texBigHalo;
    StelTextureSP texSunHalo;

    bool flagLuminanceAdaptation;

    float big3dModelHaloRadius;
};

#endif // _STELSKYDRAWER_HPP_