StelProjectorClasses.hpp

/*
 * Stellarium
 * Copyright (C) 2008 Stellarium Developers
 *
 * 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 _STELPROJECTIONS_HPP_
#define _STELPROJECTIONS_HPP_

#include "StelProjector.hpp"

#include <limits>

class StelProjectorPerspective : public StelProjector
{
public:
    StelProjectorPerspective(ModelViewTranformP func) : StelProjector(func) {;}
    virtual QString getNameI18() const;
    virtual QString getDescriptionI18() const;
    virtual float getMaxFov() const {return 120.f;}
    bool forward(Vec3f &v) const
    {
        const float r = std::sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]);
        if (v[2] < 0) {
            v[0] /= (-v[2]);
            v[1] /= (-v[2]);
            v[2] = r;
            return true;
        }
        if (v[2] > 0) {
            v[0] /= v[2];
            v[1] /= v[2];
            v[2] = r;
            return false;
        }
        v[0] = std::numeric_limits<float>::max();
        v[1] = std::numeric_limits<float>::max();
        v[2] = r;
        return false;
    }
    bool backward(Vec3d &v) const;
    float fovToViewScalingFactor(float fov) const;
    float viewScalingFactorToFov(float vsf) const;
    float deltaZoom(float fov) const;
protected:
    virtual bool hasDiscontinuity() const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, const Vec3d&) const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, double) const {return false;}
};

class StelProjectorEqualArea : public StelProjector
{
public:
    StelProjectorEqualArea(ModelViewTranformP func) : StelProjector(func) {;}
    virtual QString getNameI18() const;
    virtual QString getDescriptionI18() const;
    virtual float getMaxFov() const {return 360.f;}
    bool forward(Vec3f &v) const
    {
        const float r = std::sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]);
        const float f = std::sqrt(2.f/(r*(r-v[2])));
        v[0] *= f;
        v[1] *= f;
        v[2] = r;
        return true;
    }
    bool backward(Vec3d &v) const;
    float fovToViewScalingFactor(float fov) const;
    float viewScalingFactorToFov(float vsf) const;
    float deltaZoom(float fov) const;
protected:
    virtual bool hasDiscontinuity() const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, const Vec3d&) const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, double) const {return false;}
};

class StelProjectorStereographic : public StelProjector
{
public:
    StelProjectorStereographic(ModelViewTranformP func) : StelProjector(func) {;}
    virtual QString getNameI18() const;
    virtual QString getDescriptionI18() const;
    virtual float getMaxFov() const {return 235.f;}
    bool forward(Vec3f &v) const
    {
        const float r = std::sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]);
        const float h = 0.5f*(r-v[2]);
        if (h <= 0.f) {
            v[0] = std::numeric_limits<float>::max();
            v[1] = std::numeric_limits<float>::max();
            v[2] = -std::numeric_limits<float>::min();
            return false;
        }
        const float f = 1.f / h;
        v[0] *= f;
        v[1] *= f;
        v[2] = r;
        return true;
    }

    virtual void project(int n, const Vec3d* in, Vec3f* out)
    {
        Vec3d v;
        for (int i = 0; i < n; ++i, ++out)
        {
            v = in[i];
            modelViewTransform->forward(v);
            out->set(v[0], v[1], v[2]);
            StelProjectorStereographic::forward(*out);
            out->set(viewportCenter[0] + flipHorz * pixelPerRad * (*out)[0],
                viewportCenter[1] + flipVert * pixelPerRad * (*out)[1],
                ((*out)[2] - zNear) * oneOverZNearMinusZFar);
        }
    }

    bool backward(Vec3d &v) const;
    float fovToViewScalingFactor(float fov) const;
    float viewScalingFactorToFov(float vsf) const;
    float deltaZoom(float fov) const;
protected:
    virtual bool hasDiscontinuity() const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, const Vec3d&) const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, double) const {return false;}
};

class StelProjectorFisheye : public StelProjector
{
public:
    StelProjectorFisheye(ModelViewTranformP func) : StelProjector(func) {;}
    virtual QString getNameI18() const;
    virtual QString getDescriptionI18() const;
    virtual float getMaxFov() const {return 180.00001f;}
    bool forward(Vec3f &v) const
    {
        const float rq1 = v[0]*v[0] + v[1]*v[1];
        if (rq1 > 0.f) {
            const float h = std::sqrt(rq1);
            const float f = std::atan2(h,-v[2]) / h;
            v[0] *= f;
            v[1] *= f;
            v[2] = std::sqrt(rq1 + v[2]*v[2]);
            return true;
        }
        if (v[2] < 0.f) {
            v[0] = 0.f;
            v[1] = 0.f;
            v[2] = 1.f;
            return true;
        }
        v[0] = std::numeric_limits<float>::max();
        v[1] = std::numeric_limits<float>::max();
        v[2] = std::numeric_limits<float>::min();
        return false;
    }
    bool backward(Vec3d &v) const;
    float fovToViewScalingFactor(float fov) const;
    float viewScalingFactorToFov(float vsf) const;
    float deltaZoom(float fov) const;
protected:
    virtual bool hasDiscontinuity() const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, const Vec3d&) const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, double) const {return false;}
};

class StelProjectorHammer : public StelProjector
{
public:
    StelProjectorHammer(ModelViewTranformP func) : StelProjector(func) {;}
    virtual QString getNameI18() const;
    virtual QString getDescriptionI18() const;
    virtual float getMaxFov() const {return 360.f;}
    virtual void project(int n, const Vec3d* in, Vec3f* out)
    {
        Vec3d v;
        for (int i = 0; i < n; ++i)
        {
            v = in[i];
            modelViewTransform->forward(v);
            out[i].set(v[0], v[1], v[2]);
            StelProjectorHammer::forward(out[i]);
            out[i][0] = viewportCenter[0] + flipHorz * pixelPerRad * out[i][0];
            out[i][1] = viewportCenter[1] + flipVert * pixelPerRad * out[i][1];
            out[i][2] = (out[i][2] - zNear) * oneOverZNearMinusZFar;
        }
    }
    bool forward(Vec3f &v) const
    {
        // Hammer Aitoff
        const float r = std::sqrt(v[0]*v[0] + v[1]*v[1] + v[2]*v[2]);
        const float alpha = std::atan2(v[0],-v[2]);
        const float cosDelta = std::sqrt(1.f-v[1]*v[1]/(r*r));
        float z = std::sqrt(1.+cosDelta*std::cos(alpha/2.f));
        v[0] = 2.f*M_SQRT2*cosDelta*std::sin(alpha/2.f)/z;
        v[1] = M_SQRT2*v[1]/r/z;
        v[2] = r;
        return true;
    }
    bool backward(Vec3d &v) const;
    float fovToViewScalingFactor(float fov) const;
    float viewScalingFactorToFov(float vsf) const;
    float deltaZoom(float fov) const;
protected:
    virtual bool hasDiscontinuity() const {return true;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d& p1, const Vec3d& p2) const {return p1[0]*p2[0]<0 && !(p1[2]<0 && p2[2]<0);}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d& capN, double capD) const
    {
        static const SphericalCap cap1(1,0,0);
        static const SphericalCap cap2(-1,0,0);
        static const SphericalCap cap3(0,0,-1);
        SphericalCap cap(capN, capD);
        return cap.intersects(cap1) && cap.intersects(cap2) && cap.intersects(cap3);
    }
};

class StelProjectorCylinder : public StelProjector
{
public:
    StelProjectorCylinder(ModelViewTranformP func) : StelProjector(func) {;}
    virtual QString getNameI18() const;
    virtual QString getDescriptionI18() const;
    virtual float getMaxFov() const {return 175.f * 4.f/3.f;} // assume aspect ration of 4/3 for getting a full 360 degree horizon
    bool forward(Vec3f &win) const;
    bool backward(Vec3d &v) const;
    float fovToViewScalingFactor(float fov) const;
    float viewScalingFactorToFov(float vsf) const;
    float deltaZoom(float fov) const;
protected:
    virtual bool hasDiscontinuity() const {return true;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d& p1, const Vec3d& p2) const
    {
        return p1[0]*p2[0]<0 && !(p1[2]<0 && p2[2]<0);
    }
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d& capN, double capD) const
    {
        static const SphericalCap cap1(1,0,0);
        static const SphericalCap cap2(-1,0,0);
        static const SphericalCap cap3(0,0,-1);
        SphericalCap cap(capN, capD);
        return cap.intersects(cap1) && cap.intersects(cap2) && cap.intersects(cap2);
    }
};

class StelProjectorMercator : public StelProjector
{
public:
    StelProjectorMercator(ModelViewTranformP func) : StelProjector(func) {;}
    virtual QString getNameI18() const;
    virtual QString getDescriptionI18() const;
    virtual float getMaxFov() const {return 175.f * 4.f/3.f;} // assume aspect ration of 4/3 for getting a full 360 degree horizon
    bool forward(Vec3f &win) const;
    bool backward(Vec3d &v) const;
    float fovToViewScalingFactor(float fov) const;
    float viewScalingFactorToFov(float vsf) const;
    float deltaZoom(float fov) const;
protected:
    virtual bool hasDiscontinuity() const {return true;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d& p1, const Vec3d& p2) const
    {
        return p1[0]*p2[0]<0 && !(p1[2]<0 && p2[2]<0);
    }
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d& capN, double capD) const
    {
        static const SphericalCap cap1(1,0,0);
        static const SphericalCap cap2(-1,0,0);
        static const SphericalCap cap3(0,0,-1);
        SphericalCap cap(capN, capD);
        return cap.intersects(cap1) && cap.intersects(cap2) && cap.intersects(cap2);
    }
};

class StelProjectorOrthographic : public StelProjector
{
public:
    StelProjectorOrthographic(ModelViewTranformP func) : StelProjector(func) {;}
    virtual QString getNameI18() const;
    virtual QString getDescriptionI18() const;
    virtual float getMaxFov() const {return 179.9999f;}
    bool forward(Vec3f &win) const;
    bool backward(Vec3d &v) const;
    float fovToViewScalingFactor(float fov) const;
    float viewScalingFactorToFov(float vsf) const;
    float deltaZoom(float fov) const;
protected:
    virtual bool hasDiscontinuity() const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, const Vec3d&) const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, double) const {return false;}
};

class StelProjector2d : public StelProjector
{
public:
    StelProjector2d() : StelProjector(ModelViewTranformP(new StelProjector::Mat4dTransform(Mat4d::identity()))) {;}
    virtual QString getNameI18() const;
    virtual QString getDescriptionI18() const;
    virtual float getMaxFov() const {return 360.f;}
    bool forward(Vec3f &win) const;
    bool backward(Vec3d &v) const;
    float fovToViewScalingFactor(float fov) const;
    float viewScalingFactorToFov(float vsf) const;
    float deltaZoom(float fov) const;
protected:
    virtual bool hasDiscontinuity() const {return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, const Vec3d&) const {Q_ASSERT(0); return false;}
    virtual bool intersectViewportDiscontinuityInternal(const Vec3d&, double) const {Q_ASSERT(0); return false;}
    virtual void computeBoundingCap() {;}
};

#endif // _STELPROJECTIONS_HPP_