skyglpainter.cpp

/*
    SPDX-FileCopyrightText: 2010 Henry de Valence <hdevalence@gmail.com>
 
    SPDX-License-Identifier: GPL-2.0-or-later
*/
 
#ifdef _WIN32
#include <windows.h>
#endif
#include "skyglpainter.h"
 
#include <cstddef>
#include <Eigen/Geometry>
 
#include <GL/gl.h>
#include <QGLWidget>
 
#include "skymap.h"
#include "kstarsdata.h"
#include "Options.h"
 
#include "texturemanager.h"
 
#include "skycomponents/linelist.h"
#include "skycomponents/skiphashlist.h"
#include "skycomponents/linelistlabel.h"
#include "skycomponents/skymapcomposite.h"
#include "skycomponents/flagcomponent.h"
#include "skycomponents/satellitescomponent.h"
#include "skycomponents/supernovaecomponent.h"
#include "skycomponents/constellationartcomponent.h"
#include "skyobjects/kscomet.h"
#include "skyobjects/ksasteroid.h"
#include "skyobjects/trailobject.h"
#include "skyobjects/satellite.h"
#include "skyobjects/supernova.h"
#include "skyobjects/constellationsart.h"
 
Eigen::Vector2f SkyGLPainter::m_vertex[NUMTYPES][6 * BUFSIZE];
Eigen::Vector2f SkyGLPainter::m_texcoord[NUMTYPES][6 * BUFSIZE];
Eigen::Vector3f SkyGLPainter::m_color[NUMTYPES][6 * BUFSIZE];
int SkyGLPainter::m_idx[NUMTYPES];
bool SkyGLPainter::m_init = false;
 
SkyGLPainter::SkyGLPainter(QGLWidget *widget) : SkyPainter()
{
    m_widget = widget;
    if (!m_init)
    {
        qDebug() << "Initializing texcoord arrays...\n";
        for (int i = 0; i < NUMTYPES; ++i)
        {
            m_idx[i] = 0;
            for (int j = 0; j < BUFSIZE; ++j)
            {
                m_texcoord[i][6 * j + 0] = Eigen::Vector2f(0, 0);
                m_texcoord[i][6 * j + 1] = Eigen::Vector2f(1, 0);
                m_texcoord[i][6 * j + 2] = Eigen::Vector2f(0, 1);
                m_texcoord[i][6 * j + 3] = Eigen::Vector2f(0, 1);
                m_texcoord[i][6 * j + 4] = Eigen::Vector2f(1, 0);
                m_texcoord[i][6 * j + 5] = Eigen::Vector2f(1, 1);
            }
        }
        //Generate textures that were loaded before the SkyMap was
        m_init = true;
    }
}
 
void SkyGLPainter::drawBuffer(int type)
{
    // Prevent crash if type > UNKNOWN
    if (type > SkyObject::TYPE_UNKNOWN)
        type = SkyObject::TYPE_UNKNOWN;
 
    //printf("Drawing buffer for type %d, has %d objects\n", type, m_idx[type]);
    if (m_idx[type] == 0)
        return;
 
    glEnable(GL_TEXTURE_2D);
    switch (type)
    {
        case 3:
        case 13:
            TextureManager::bindTexture("open-cluster", m_widget);
            break;
        case 4:
            TextureManager::bindTexture("globular-cluster", m_widget);
            break;
        case 6:
            TextureManager::bindTexture("planetary-nebula", m_widget);
            break;
        case 5:
        case 7:
        case 15:
            TextureManager::bindTexture("gaseous-nebula", m_widget);
            break;
        case 8:
        case 16:
            TextureManager::bindTexture("galaxy", m_widget);
            break;
        case 14:
            TextureManager::bindTexture("galaxy-cluster", m_widget);
            break;
        case 0:
        case 1:
        default:
            TextureManager::bindTexture("star", m_widget);
            break;
    }
 
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
    glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_COLOR_ARRAY);
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
 
    glVertexPointer(2, GL_FLOAT, 0, &m_vertex[type]);
    glTexCoordPointer(2, GL_FLOAT, 0, &m_texcoord[type]);
    glColorPointer(3, GL_FLOAT, 0, &m_color[type]);
 
    glDrawArrays(GL_TRIANGLES, 0, 6 * m_idx[type]);
    m_idx[type] = 0;
 
    glDisableClientState(GL_VERTEX_ARRAY);
    glDisableClientState(GL_COLOR_ARRAY);
    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
 
bool SkyGLPainter::addItem(SkyPoint *p, int type, float width, char sp)
{
    bool visible = false;
    Eigen::Vector2f vec = m_proj->toScreenVec(p, true, &visible);
    if (!visible)
        return false;
 
    // Prevent crash if type > UNKNOWN
    if (type > SkyObject::TYPE_UNKNOWN)
        type = SkyObject::TYPE_UNKNOWN;
 
    //If the buffer is full, flush it
    if (m_idx[type] == BUFSIZE)
    {
        drawBuffer(type);
    }
 
    int i   = 6 * m_idx[type];
    float w = width / 2.;
 
    m_vertex[type][i + 0] = vec + Eigen::Vector2f(-w, -w);
    m_vertex[type][i + 1] = vec + Eigen::Vector2f(w, -w);
    m_vertex[type][i + 2] = vec + Eigen::Vector2f(-w, w);
    m_vertex[type][i + 3] = vec + Eigen::Vector2f(-w, w);
    m_vertex[type][i + 4] = vec + Eigen::Vector2f(w, -w);
    m_vertex[type][i + 5] = vec + Eigen::Vector2f(w, w);
 
    Eigen::Vector3f c(1., 1., 1.);
    if (sp != 'x' && Options::starColorMode() != 0)
    {
        // We have a star and aren't drawing real star colors
        switch (Options::starColorMode())
        {
            case 1: // solid red
                c = Eigen::Vector3f(255. / 255., 0., 0.);
                break;
            case 2: // solid black
                c = Eigen::Vector3f(0., 0., 0.);
                break;
            case 3: // Solid white
                c = Eigen::Vector3f(1., 1., 1.);
                break;
        }
    }
    else
    {
        QColor starColor;
 
        // Set RGB values into QColor
        switch (sp)
        {
            case 'o':
            case 'O':
                starColor.setRgb(153, 153, 255);
                break;
            case 'b':
            case 'B':
                starColor.setRgb(151, 233, 255);
                break;
            case 'a':
            case 'A':
                starColor.setRgb(153, 255, 255);
                break;
            case 'f':
            case 'F':
                starColor.setRgb(219, 255, 135);
                break;
            case 'g':
            case 'G':
                starColor.setRgb(255, 255, 153);
                break;
            case 'k':
            case 'K':
                starColor.setRgb(255, 193, 153);
                break;
            case 'm':
            case 'M':
                starColor.setRgb(255, 153, 153);
                break;
            case 'x':
                starColor.setRgb(m_pen[0] * 255, m_pen[1] * 255, m_pen[2] * 255);
                break;
            default:
                starColor.setRgb(153, 255, 255);
                break; // If we don't know what spectral type, we use the same as 'A' (See SkyQPainter)
        }
 
        // Convert to HSV space using QColor's methods and adjust saturation.
        int h, s, v;
        starColor.getHsv(&h, &s, &v);
        s = (Options::starColorIntensity() / 10.) *
            200.; // Rewrite the saturation based on the star color intensity setting, 200 is the hard-wired max saturation, just to approximately match up with QPainter mode.
        starColor.setHsv(h, s, v);
 
        // Get RGB ratios and put them in 'c'
        c = Eigen::Vector3f(starColor.redF(), starColor.greenF(), starColor.blueF());
    }
    for (int j = 0; j < 6; ++j)
    {
        m_color[type][i + j] = c;
    }
 
    ++m_idx[type];
    return true;
}
 
void SkyGLPainter::drawTexturedRectangle(const QImage &img, const Eigen::Vector2f &pos, const float angle, const float sizeX,
                                         const float sizeY)
{
    // Set up texture
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
    glEnable(GL_TEXTURE_2D);
    TextureManager::bindFromImage(img, m_widget);
 
    // Render rectangle
    glPushMatrix();
    glTranslatef(pos.x(), pos.y(), 0);
    glRotatef(angle, 0, 0, 1);
    glScalef(sizeX, sizeY, 1);
 
    glBegin(GL_QUADS);
    // Note! Y coordinate of texture is mirrored w.r.t. to
    // vertex coordinates to account for difference between
    // OpenGL and QPainter coordinate system.
    // Otherwise image would appear mirrored
    glTexCoord2f(0, 1);
    glVertex2f(-0.5, -0.5);
 
    glTexCoord2f(1, 1);
    glVertex2f(0.5, -0.5);
 
    glTexCoord2f(1, 0);
    glVertex2f(0.5, 0.5);
 
    glTexCoord2f(0, 0);
    glVertex2f(-0.5, 0.5);
    glEnd();
 
    glPopMatrix();
}
 
bool SkyGLPainter::drawPlanet(KSPlanetBase *planet)
{
    //If it's surely not visible, just stop now
    if (!m_proj->checkVisibility(planet))
        return false;
 
    float zoom         = Options::zoomFactor();
    float fakeStarSize = (10.0 + log10(zoom) - log10(MINZOOM)) * (10 - planet->mag()) / 10;
    fakeStarSize       = qMin(fakeStarSize, 20.f);
 
    float size = planet->angSize() * dms::PI * zoom / 10800.0;
    if (size < fakeStarSize || planet->image().isNull())
    {
        // Draw them as bright stars of appropriate color instead of images
        char spType;
        //FIXME: do these need i18n?
        if (planet->name() == xi18n("Sun"))
        {
            spType = 'G';
        }
        else if (planet->name() == xi18n("Mars"))
        {
            spType = 'K';
        }
        else if (planet->name() == xi18n("Jupiter") || planet->name() == xi18n("Mercury") ||
                 planet->name() == xi18n("Saturn"))
        {
            spType = 'F';
        }
        else
        {
            spType = 'B';
        }
        return addItem(planet, planet->type(), qMin(fakeStarSize, (float)20.), spType);
    }
    else
    {
        // Draw them as textures
        bool visible = false;
        Eigen::Vector2f pos = m_proj->toScreenVec(planet, true, &visible);
        if (!visible)
            return false;
 
        //Because Saturn has rings, we inflate its image size by a factor 2.5
        if (planet->name() == "Saturn")
            size *= 2.5;
 
        drawTexturedRectangle(planet->image(), pos, m_proj->findPA(planet, pos.x(), pos.y()), size, size);
        return true;
    }
}
 
bool SkyGLPainter::drawPointSource(const SkyPoint *loc, float mag, char sp)
{
    //If it's surely not visible, just stop now
    if (!m_proj->checkVisibility(loc))
        return false;
    return addItem(loc, SkyObject::STAR, starWidth(mag), sp);
}
 
void SkyGLPainter::drawSkyPolygon(LineList *list)
{
    SkyList *points = list->points();
    bool isVisible, isVisibleLast;
    SkyPoint *pLast = points->last();
    Eigen::Vector2f oLast  = m_proj->toScreenVec(pLast, true, &isVisibleLast);
    // & with the result of checkVisibility to clip away things below horizon
    isVisibleLast &= m_proj->checkVisibility(pLast);
 
    //Guess that we will require around the same number of items as in points.
    QVector<Eigen::Vector2f> polygon;
    polygon.reserve(points->size());
    for (int i = 0; i < points->size(); ++i)
    {
        SkyPoint *pThis = points->at(i);
        Eigen::Vector2f oThis  = m_proj->toScreenVec(pThis, true, &isVisible);
        // & with the result of checkVisibility to clip away things below horizon
        isVisible &= m_proj->checkVisibility(pThis);
 
        if (isVisible && isVisibleLast)
        {
            polygon << oThis;
        }
        else if (isVisibleLast)
        {
            Eigen::Vector2f oMid = m_proj->clipLineVec(pLast, pThis);
            polygon << oMid;
        }
        else if (isVisible)
        {
            Eigen::Vector2f oMid = m_proj->clipLineVec(pThis, pLast);
            polygon << oMid;
            polygon << oThis;
        }
 
        pLast         = pThis;
        oLast         = oThis;
        isVisibleLast = isVisible;
    }
 
// false -> makes kstars slower but is always accurate
// true -> faster but potentially results in incorrect rendering
#define KSTARS_ASSUME_CONVEXITY false
    if (polygon.size())
    {
        drawPolygon(polygon, KSTARS_ASSUME_CONVEXITY);
    }
}
 
void SkyGLPainter::drawPolygon(const QVector<Eigen::Vector2f> &polygon, bool convex, bool flush_buffers)
{
    //Flush all buffers
    if (flush_buffers)
    {
        for (int i = 0; i < NUMTYPES; ++i)
        {
            drawBuffer(i);
        }
    }
    glDisable(GL_TEXTURE_2D);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    if (!convex)
    {
        //Set up the stencil buffer and disable the color buffer
        glClear(GL_STENCIL_BUFFER_BIT);
        glColorMask(0, 0, 0, 0);
        glEnable(GL_STENCIL_TEST);
        glStencilFunc(GL_ALWAYS, 0, 0);
        glStencilOp(GL_INVERT, GL_INVERT, GL_INVERT);
        //Now draw a triangle fan. Because of the GL_INVERT,
        //this will fill the stencil buffer with odd-even fill.
        glEnableClientState(GL_VERTEX_ARRAY);
        glVertexPointer(2, GL_FLOAT, 0, polygon.data());
        glDrawArrays(GL_TRIANGLE_FAN, 0, polygon.size());
        glDisableClientState(GL_VERTEX_ARRAY);
 
        //Now draw the stencil:
        glStencilFunc(GL_NOTEQUAL, 0, 0xffffffff);
        glColorMask(1, 1, 1, 1);
        glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
        glBegin(GL_QUADS);
        glVertex2f(0, 0);
        glVertex2f(0, m_widget->height());
        glVertex2f(m_widget->width(), m_widget->height());
        glVertex2f(m_widget->width(), 0);
        glEnd();
        glDisable(GL_STENCIL_TEST);
    }
    else
    {
        glEnableClientState(GL_VERTEX_ARRAY);
        glVertexPointer(2, GL_FLOAT, 0, polygon.data());
        glDrawArrays(GL_POLYGON, 0, polygon.size());
        glDisableClientState(GL_VERTEX_ARRAY);
    }
}
 
void SkyGLPainter::drawHorizon(bool filled, SkyPoint *labelPoint, bool *drawLabel)
{
    QVector<Eigen::Vector2f> ground = m_proj->groundPoly(labelPoint, drawLabel);
 
    if (ground.size())
    {
        if (filled)
        {
            glDisableClientState(GL_COLOR_ARRAY);
            drawPolygon(ground, false, false);
        }
        else
        {
            glDisable(GL_TEXTURE_2D);
            glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
            glEnableClientState(GL_VERTEX_ARRAY);
            glVertexPointer(2, GL_FLOAT, 0, ground.data());
            glDrawArrays(GL_LINE_LOOP, 0, ground.size());
            glDisableClientState(GL_VERTEX_ARRAY);
        }
    }
}
 
//This implementation is *correct* but slow.
void SkyGLPainter::drawSkyPolyline(LineList *list, SkipHashList *skipList, LineListLabel *label)
{
    glDisable(GL_TEXTURE_2D);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glBegin(GL_LINE_STRIP);
    SkyList *points = list->points();
    bool isVisible, isVisibleLast;
    Eigen::Vector2f oLast = m_proj->toScreenVec(points->first(), true, &isVisibleLast);
    // & with the result of checkVisibility to clip away things below horizon
    isVisibleLast &= m_proj->checkVisibility(points->first());
    if (isVisibleLast)
    {
        glVertex2fv(oLast.data());
    }
 
    for (int i = 1; i < points->size(); ++i)
    {
        Eigen::Vector2f oThis = m_proj->toScreenVec(points->at(i), true, &isVisible);
        // & with the result of checkVisibility to clip away things below horizon
        isVisible &= m_proj->checkVisibility(points->at(i));
 
        bool doSkip = (skipList ? skipList->skip(i) : false);
        //This tells us whether we need to end the current line or whether we
        //are to keep drawing into it. If we skip, then we are going to have to end.
        bool shouldEnd = doSkip;
 
        if (!doSkip)
        {
            if (isVisible && isVisibleLast)
            {
                glVertex2fv(oThis.data());
                if (label)
                {
                    label->updateLabelCandidates(oThis.x(), oThis.y(), list, i);
                }
            }
            else if (isVisibleLast)
            {
                Eigen::Vector2f oMid = m_proj->clipLineVec(points->at(i - 1), points->at(i));
                glVertex2fv(oMid.data());
                //If the last point was visible but this one isn't we are at
                //the end of a strip, so we need to end
                shouldEnd = true;
            }
            else if (isVisible)
            {
                Eigen::Vector2f oMid = m_proj->clipLineVec(points->at(i), points->at(i - 1));
                glVertex2fv(oMid.data());
                glVertex2fv(oThis.data());
            }
        }
 
        if (shouldEnd)
        {
            glEnd();
            glBegin(GL_LINE_STRIP);
            if (isVisible)
            {
                glVertex2fv(oThis.data());
            }
        }
 
        isVisibleLast = isVisible;
    }
    glEnd();
}
 
//FIXME: implement these two
 
void SkyGLPainter::drawObservingList(const QList<SkyObject *> &obs)
{
    // TODO: Generalize to drawTargetList or something like that. Make
    // texture changeable etc.
    // TODO: Draw labels when required
 
    foreach (SkyObject *obj, obs)
    {
        if (!m_proj->checkVisibility(obj))
            continue;
        bool visible;
        Eigen::Vector2f vec = m_proj->toScreenVec(obj, true, &visible);
        if (!visible || !m_proj->onScreen(vec))
            continue;
        const float size = 30.;
        QImage obsmarker = TextureManager::getImage("obslistsymbol");
        drawTexturedRectangle(obsmarker, vec, 0, size, size);
    }
}
 
void SkyGLPainter::drawFlags()
{
    KStarsData *data = KStarsData::Instance();
    SkyPoint *point;
    QImage image;
    const QString label;
    bool visible = false;
    Eigen::Vector2f vec;
    int i;
 
    for (i = 0; i < data->skyComposite()->flags()->size(); i++)
    {
        point = data->skyComposite()->flags()->pointList().at(i);
        image = data->skyComposite()->flags()->image(i);
 
        // Set Horizontal coordinates
        point->EquatorialToHorizontal(data->lst(), data->geo()->lat());
 
        // Get flag position on screen
        vec = m_proj->toScreenVec(point, true, &visible);
 
        // Return if flag is not visible
        if (!visible || !m_proj->onScreen(vec))
            continue;
 
        const QImage &img =
            data->skyComposite()->flags()->imageName(i) == "Default" ? TextureManager::getImage("defaultflag") : image;
 
        drawTexturedRectangle(img, vec, 0, img.width(), img.height());
        drawText(vec.x(), vec.y(), data->skyComposite()->flags()->label(i), QFont("Courier New", 10, QFont::Bold),
                 data->skyComposite()->flags()->labelColor(i));
    }
}
 
void SkyGLPainter::drawText(int x, int y, const QString text, QFont font, QColor color)
{
    // Return if text is empty
    if (text.isEmpty())
        return;
 
    int longest, tex_size = 2;
 
    // Get size of text
    QFontMetrics fm(font);
    const QRect bounding_rect = fm.boundingRect(text);
 
    // Compute texture size
    if (bounding_rect.width() > bounding_rect.height())
        longest = bounding_rect.width();
    else
        longest = bounding_rect.height();
 
    while (tex_size < longest)
    {
        tex_size *= 2;
    }
 
    // Create image of text
    QImage text_image(tex_size, tex_size, QImage::Format_ARGB32);
    text_image.fill(Qt::transparent);
    QPainter p(&text_image);
    p.setFont(font);
    p.setPen(color);
    p.drawText(0, tex_size / 2, text);
    p.end();
 
    // Create texture
    float w  = text_image.width();
    float h  = text_image.height();
    float vx = x + 0.5 * w + 10;
    float vy = y - 10;
    drawTexturedRectangle(text_image, Eigen::Vector2f(vx, vy), 0, w, h);
}
 
bool SkyGLPainter::drawConstellationArtImage(ConstellationsArt *obj)
{
}
 
void SkyGLPainter::drawSkyLine(SkyPoint *a, SkyPoint *b)
{
    bool aVisible, bVisible;
    Eigen::Vector2f aScreen = m_proj->toScreenVec(a, true, &aVisible);
    Eigen::Vector2f bScreen = m_proj->toScreenVec(b, true, &bVisible);
 
    glDisable(GL_TEXTURE_2D);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glBegin(GL_LINE_STRIP);
 
    //THREE CASES:
    if (aVisible && bVisible)
    {
        //Both a,b visible, so paint the line normally:
        glVertex2fv(aScreen.data());
        glVertex2fv(bScreen.data());
    }
    else if (aVisible)
    {
        //a is visible but b isn't:
        glVertex2fv(aScreen.data());
        glVertex2fv(m_proj->clipLineVec(a, b).data());
    }
    else if (bVisible)
    {
        //b is visible but a isn't:
        glVertex2fv(bScreen.data());
        glVertex2fv(m_proj->clipLineVec(b, a).data());
    } //FIXME: what if both are offscreen but the line isn't?
 
    glEnd();
}
 
void SkyGLPainter::drawSkyBackground()
{
    glDisable(GL_TEXTURE_2D);
    QColor bg = KStarsData::Instance()->colorScheme()->colorNamed("SkyColor");
    glClearColor(bg.redF(), bg.greenF(), bg.blueF(), bg.alphaF());
    glClear(GL_COLOR_BUFFER_BIT);
}
 
void SkyGLPainter::end()
{
    for (int i = 0; i < NUMTYPES; ++i)
    {
        drawBuffer(i);
    }
}
 
void SkyGLPainter::begin()
{
    m_proj = m_sm->projector();
 
    //Load ortho projection
    glViewport(0, 0, m_widget->width(), m_widget->height());
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glOrtho(0, m_widget->width(), m_widget->height(), 0, -1, 1);
 
    //reset modelview matrix
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
 
    //Set various parameters
    glDisable(GL_LIGHTING);
    glDisable(GL_COLOR_MATERIAL);
    glDisable(GL_CULL_FACE);
    glDisable(GL_DEPTH_TEST);
    glDepthMask(GL_FALSE);
    glPointSize(1.);
    glEnable(GL_POINT_SMOOTH);
    glEnable(GL_LINE_SMOOTH);
    glEnable(GL_POLYGON_SMOOTH);
    glLineStipple(1, 0xCCCC);
    glEnable(GL_BLEND);
 
    glClearStencil(0);
}
 
void SkyGLPainter::setBrush(const QBrush &brush)
{
    Q_UNUSED(brush);
    /*
    QColor c = brush.color();
    m_pen = Eigen::Vector4f( c.redF(), c.greenF(), c.blueF(), c.alphaF() );
    glColor4fv( m_pen.data() );
    */
}
 
void SkyGLPainter::setPen(const QPen &pen)
{
    QColor c = pen.color();
    m_pen    = Eigen::Vector4f(c.redF(), c.greenF(), c.blueF(), c.alphaF());
    glColor4fv(m_pen.data());
    glLineWidth(pen.widthF());
    if (pen.style() != Qt::SolidLine)
    {
        glEnable(GL_LINE_STIPPLE);
    }
    else
    {
        glDisable(GL_LINE_STIPPLE);
    }
}
 
void SkyGLPainter::drawSatellite(Satellite *sat)
{
    KStarsData *data = KStarsData::Instance();
    bool visible     = false;
    Eigen::Vector2f pos, vertex;
 
    sat->HorizontalToEquatorial(data->lst(), data->geo()->lat());
 
    pos = m_proj->toScreenVec(sat, true, &visible);
 
    if (!visible || !m_proj->onScreen(pos))
        return;
 
    if (Options::drawSatellitesLikeStars())
    {
        drawPointSource(sat, 3.5, 'B');
    }
    else
    {
        if (sat->isVisible())
            setPen(data->colorScheme()->colorNamed("VisibleSatColor"));
        else
            setPen(data->colorScheme()->colorNamed("SatColor"));
 
        glDisable(GL_TEXTURE_2D);
        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
        glBegin(GL_QUADS);
 
        vertex = pos + Eigen::Vector2f(-1.0, -1.0);
        glVertex2fv(vertex.data());
        vertex = pos + Eigen::Vector2f(1.0, -1.0);
        glVertex2fv(vertex.data());
        vertex = pos + Eigen::Vector2f(1.0, 1.0);
        glVertex2fv(vertex.data());
        vertex = pos + Eigen::Vector2f(-1.0, 1.0);
        glVertex2fv(vertex.data());
 
        glEnd();
    }
 
    if (Options::showSatellitesLabels())
        data->skyComposite()->satellites()->drawLabel(sat, QPointF(pos.x(), pos.y()));
}
 
bool SkyGLPainter::drawSupernova(Supernova *sup)
{
    KStarsData *data = KStarsData::Instance();
    bool visible     = false;
    Eigen::Vector2f pos, vertex;
 
    sup->HorizontalToEquatorial(data->lst(), data->geo()->lat());
 
    pos = m_proj->toScreenVec(sup, true, &visible);
 
    if (!visible || !m_proj->onScreen(pos))
        return false;
    setPen(data->colorScheme()->colorNamed("SupernovaColor"));
 
    glDisable(GL_TEXTURE_2D);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 
    glBegin(GL_LINES);
    vertex = pos + Eigen::Vector2f(2.0, 0.0);
    glVertex2fv(vertex.data());
    vertex = pos + Eigen::Vector2f(-2.0, 0.0);
    glVertex2fv(vertex.data());
    glEnd();
 
    glBegin(GL_LINES);
    vertex = pos + Eigen::Vector2f(0.0, 2.0);
    glVertex2fv(vertex.data());
    vertex = pos + Eigen::Vector2f(0.0, -2.0);
    glVertex2fv(vertex.data());
    glEnd();
 
    return true;
}