4853788370

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github

Committed by Alexander V. Wolf

Commit Message

Special patch for John Simple

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/src/core/StelPainter.cpp

/*
 * Stellarium
 * Copyright (C) 2008 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.
 */

#include "StelPainter.hpp"

#include "StelApp.hpp"
#include "StelMainView.hpp"
#include "StelLocaleMgr.hpp"
#include "StelProjector.hpp"
#include "StelProjectorClasses.hpp"
#include "StelUtils.hpp"
#include "StelTextureMgr.hpp"
#include "SaturationShader.hpp"

#include <QDebug>
#include <QString>
#include <QSettings>
#include <QPainter>
#include <QMutex>
#include <QVarLengthArray>
#include <QPaintEngine>
#include <QCache>
#include <QOpenGLVertexArrayObject>
#include <QOpenGLPaintDevice>
#include <QOpenGLBuffer>
#include <QOpenGLShader>
#include <QOpenGLTexture>
#include <QApplication>

static const int TEX_CACHE_LIMIT = 7000000;

#ifndef NDEBUG
QMutex* StelPainter::globalMutex = new QMutex();
#endif

QCache<QByteArray, StringTexture> StelPainter::texCache(TEX_CACHE_LIMIT);
QOpenGLShaderProgram* StelPainter::texturesShaderProgram=Q_NULLPTR;
QOpenGLShaderProgram* StelPainter::basicShaderProgram=Q_NULLPTR;
QOpenGLShaderProgram* StelPainter::colorShaderProgram=Q_NULLPTR;
QOpenGLShaderProgram* StelPainter::texturesColorShaderProgram=Q_NULLPTR;
QOpenGLShaderProgram* StelPainter::wideLineShaderProgram=Q_NULLPTR;
QOpenGLShaderProgram* StelPainter::colorfulWideLineShaderProgram=Q_NULLPTR;
StelPainter::BasicShaderVars StelPainter::basicShaderVars;
StelPainter::TexturesShaderVars StelPainter::texturesShaderVars;
StelPainter::BasicShaderVars StelPainter::colorShaderVars;
StelPainter::TexturesColorShaderVars StelPainter::texturesColorShaderVars;
StelPainter::WideLineShaderVars StelPainter::wideLineShaderVars;
StelPainter::ColorfulWideLineShaderVars StelPainter::colorfulWideLineShaderVars;
bool StelPainter::multisamplingEnabled=false;

StelPainter::GLState::GLState(QOpenGLFunctions* gl)
        : blend(false),
          blendSrc(GL_SRC_ALPHA), blendDst(GL_ONE_MINUS_SRC_ALPHA),
          depthTest(false),
          depthMask(false),
          cullFace(false),
          lineSmooth(false),
          lineWidth(1.0f),
          gl(gl)
{
}

void StelPainter::GLState::apply()
{
        if(blend)
                gl->glEnable(GL_BLEND);
        else
                gl->glDisable(GL_BLEND);
        gl->glBlendFunc(blendSrc,blendDst);
        if(depthTest)
                gl->glEnable(GL_DEPTH_TEST);
        else
                gl->glDisable(GL_DEPTH_TEST);
        gl->glDepthMask(depthMask);
        if(cullFace)
                gl->glEnable(GL_CULL_FACE);
        else
                gl->glDisable(GL_CULL_FACE);
#ifdef GL_LINE_SMOOTH
        if(!QOpenGLContext::currentContext()->isOpenGLES())
        {
                if (lineSmooth)
                        gl->glEnable(GL_LINE_SMOOTH);
                else
                        gl->glDisable(GL_LINE_SMOOTH);
        }
#endif
}

void StelPainter::GLState::reset()
{
        *this = GLState(gl);
        apply();
}

bool StelPainter::linkProg(QOpenGLShaderProgram* prog, const QString& name)
{
        bool ret = prog->link();
        QString log = prog->log();
        if (!ret || (!log.isEmpty() && !log.contains("Link was successful") && !(log=="No errors."))) //"No errors." returned on some Intel drivers
                qWarning().noquote() << QString("StelPainter: Warnings while linking %1 shader program:\n%2").arg(name, prog->log());
        return ret;
}

StelPainter::StelPainter(const StelProjectorP& proj)
        : QOpenGLFunctions(QOpenGLContext::currentContext())
        , glState(this)
        , vao(new QOpenGLVertexArrayObject)
        , verticesVBO(new QOpenGLBuffer(QOpenGLBuffer::VertexBuffer))
        , indicesVBO(new QOpenGLBuffer(QOpenGLBuffer::IndexBuffer))
{
        Q_ASSERT(proj);

#ifndef NDEBUG
        Q_ASSERT(globalMutex);
        
        GLenum er = glGetError();
        if (er!=GL_NO_ERROR)
        {
                if (er==GL_INVALID_OPERATION)
                        qFatal("Invalid openGL operation. It is likely that you used openGL calls without having a valid instance of StelPainter");
        }

        // Lock the global mutex ensuring that no other instances of StelPainter are currently being used
        if (globalMutex->tryLock()==false)
        {
                qFatal("There can be only 1 instance of StelPainter at a given time");
        }
#endif

        //TODO: is this still required, and is there some Qt way to fix it? 0x11111111 is a bit peculiar, how was it chosen?
        // Fix some problem when using Qt OpenGL2 engine
        glStencilMask(0x11111111);
        glState.apply(); //apply default OpenGL state
        setProjector(proj);

        vao->create();
        indicesVBO->create();
        indicesVBO->setUsagePattern(QOpenGLBuffer::StreamDraw);
        verticesVBO->create();
        verticesVBO->setUsagePattern(QOpenGLBuffer::StreamDraw);
}

void StelPainter::setProjector(const StelProjectorP& p)
{
        prj=p;
        // Init GL viewport to current projector values
        glViewport(prj->viewportXywh[0], prj->viewportXywh[1], prj->viewportXywh[2], prj->viewportXywh[3]);
        glFrontFace(prj->needGlFrontFaceCW()?GL_CW:GL_CCW);
}

StelPainter::~StelPainter()
{
        //reset opengl state
        glState.reset();

#ifndef NDEBUG
        GLenum er = glGetError();
        if (er!=GL_NO_ERROR)
        {
                if (er==GL_INVALID_OPERATION)
                        qFatal("Invalid openGL operation detected in ~StelPainter()");
        }

        // We are done with this StelPainter
        globalMutex->unlock();
#endif
}


void StelPainter::setFont(const QFont& font)
{
        currentFont = font;
}

void StelPainter::setColor(float r, float g, float b, float a)
{
        currentColor.set(r,g,b,a);
}

void StelPainter::setColor(Vec3f rgb, float a)
{
        currentColor.set(rgb[0],rgb[1],rgb[2],a);
}

void StelPainter::setColor(Vec4f rgba)
{
        currentColor=rgba;
}

Vec4f StelPainter::getColor() const
{
        return currentColor;
}

QFontMetrics StelPainter::getFontMetrics() const
{
        return QFontMetrics(currentFont);
}

void StelPainter::setBlending(bool enableBlending, GLenum blendSrc, GLenum blendDst)
{
        if(enableBlending != glState.blend)
        {
                glState.blend = enableBlending;
                if(enableBlending)
                        glEnable(GL_BLEND);
                else
                        glDisable(GL_BLEND);
        }
        if(enableBlending)
        {
                if(blendSrc!=glState.blendSrc||blendDst!=glState.blendDst)
                {
                        glState.blendSrc = blendSrc;
                        glState.blendDst = blendDst;
                        glBlendFunc(blendSrc,blendDst);
                }
        }
}

bool StelPainter::getBlending(GLenum *src, GLenum *dst) const
{
        if (dst!=Q_NULLPTR)
                *dst=glState.blendDst;
        if (src!=Q_NULLPTR)
                *src=glState.blendSrc;
        return glState.blend;
}

void StelPainter::setDepthTest(bool enable)
{
        if(glState.depthTest != enable)
        {
                glState.depthTest = enable;
                if(enable)
                        glEnable(GL_DEPTH_TEST);
                else
                        glDisable(GL_DEPTH_TEST);
        }
}

void StelPainter::setDepthMask(bool enable)
{
        if(glState.depthMask != enable)
        {
                glState.depthMask = enable;
                if(enable)
                        glDepthMask(GL_TRUE);
                else
                        glDepthMask(GL_FALSE);
        }
}

void StelPainter::setCullFace(bool enable)
{
        if(glState.cullFace!=enable)
        {
                glState.cullFace = enable;
                if(enable)
                        glEnable(GL_CULL_FACE);
                else
                        glDisable(GL_CULL_FACE);
        }
}

void StelPainter::setLineSmooth(bool enable)
{
#ifdef GL_LINE_SMOOTH
        if (!QOpenGLContext::currentContext()->isOpenGLES() && enable!=glState.lineSmooth)
        {
                glState.lineSmooth = enable;
                if(enable)
                        glEnable(GL_LINE_SMOOTH);
                else
                        glDisable(GL_LINE_SMOOTH);
        }
#else
        Q_UNUSED(enable); //noop
#endif
}

void StelPainter::setLineWidth(float width)
{
        if(fabs(glState.lineWidth - width) < 1.e-10f)
                return;

        glState.lineWidth = width;

        if(width > 1 && StelMainView::getInstance().getGLInformation().isCoreProfile)
                return;

        glLineWidth(width);
}

///////////////////////////////////////////////////////////////////////////
// Standard methods for drawing primitives

// Fill with black around the circle
void StelPainter::drawViewportShape(void)
{
        if (prj->maskType != StelProjector::MaskDisk)
                return;

        bool oldBlendState = glState.blend;
        glDisable(GL_BLEND);
        setColor(0.f,0.f,0.f);

        GLfloat innerRadius = 0.5f*static_cast<float>(prj->viewportFovDiameter);
        GLfloat outerRadius = static_cast<float>(prj->getViewportWidth()+prj->getViewportHeight());
        GLint slices = 239;

        GLfloat sinCache[240];
        GLfloat cosCache[240];
        GLfloat vertices[(240+1)*2][3];
        GLfloat deltaRadius;
        GLfloat radiusHigh;

        if (outerRadius<=0.0f || innerRadius<0.0f ||innerRadius > outerRadius)
        {
                Q_ASSERT(0);
                return;
        }

        /* Compute length (needed for normal calculations) */
        deltaRadius=outerRadius-innerRadius;

        /* Cache is the vertex locations cache */
        for (int i=0; i<=slices; i++)
        {
                GLfloat angle=(M_PIf*2.0f)*static_cast<float>(i)/static_cast<float>(slices);
                sinCache[i]=static_cast<GLfloat>(sin(angle));
                cosCache[i]=static_cast<GLfloat>(cos(angle));
        }

        sinCache[slices]=sinCache[0];
        cosCache[slices]=cosCache[0];

        /* Enable arrays */
        enableClientStates(true);
        setVertexPointer(3, GL_FLOAT, vertices);

        radiusHigh=outerRadius-deltaRadius;
        for (int i=0; i<=slices; i++)
        {
                vertices[i*2][0]= static_cast<float>(prj->viewportCenter[0]) + outerRadius*sinCache[i];
                vertices[i*2][1]= static_cast<float>(prj->viewportCenter[1]) + outerRadius*cosCache[i];
                vertices[i*2][2] = 0.0f;
                vertices[i*2+1][0]= static_cast<float>(prj->viewportCenter[0]) + radiusHigh*sinCache[i];
                vertices[i*2+1][1]= static_cast<float>(prj->viewportCenter[1]) + radiusHigh*cosCache[i];
                vertices[i*2+1][2] = 0.0f;
        }
        drawFromArray(TriangleStrip, (slices+1)*2, 0, false);
        enableClientStates(false);
        if(oldBlendState)
                glEnable(GL_BLEND);
}

void StelPainter::computeFanDisk(float radius, uint innerFanSlices, uint level, QVector<Vec3d>& vertexArr, QVector<Vec2f>& texCoordArr)
{
        Q_ASSERT(level<32);
        float rad[64];
        uint i,j;
        rad[level] = radius;
#pragma warning(suppress: 4146)
        for (i=level-1u;i!=-1u;--i)
        {
                rad[i] = rad[i+1]*(1.f-M_PIf/(innerFanSlices<<(i+1)))*2.f/3.f;
        }
        uint slices = innerFanSlices<<level;

        float* cos_sin_theta = StelUtils::ComputeCosSinTheta(static_cast<uint>(slices));
        float* cos_sin_theta_p;
        uint slices_step = 2;
        float x,y,xa,ya;
        radius*=2.f;
        vertexArr.resize(0);
        texCoordArr.resize(0);
        for (i=level;i>0;--i,slices_step<<=1)
        {
                for (j=0,cos_sin_theta_p=cos_sin_theta; j<slices-1; j+=slices_step,cos_sin_theta_p+=2*slices_step)
                {
                        xa = rad[i]*cos_sin_theta_p[slices_step];
                        ya = rad[i]*cos_sin_theta_p[slices_step+1];
                        texCoordArr << Vec2f(0.5f+xa/radius, 0.5f+ya/radius);
                        vertexArr << Vec3d(static_cast<double>(xa), static_cast<double>(ya), 0);

                        x = rad[i]*cos_sin_theta_p[2*slices_step];
                        y = rad[i]*cos_sin_theta_p[2*slices_step+1];
                        texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                        vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);

                        x = rad[i-1]*cos_sin_theta_p[2*slices_step];
                        y = rad[i-1]*cos_sin_theta_p[2*slices_step+1];
                        texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                        vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);

                        texCoordArr << Vec2f(0.5f+xa/radius, 0.5f+ya/radius);
                        vertexArr << Vec3d(static_cast<double>(xa), static_cast<double>(ya), 0);
                        texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                        vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);

                        x = rad[i-1]*cos_sin_theta_p[0];
                        y = rad[i-1]*cos_sin_theta_p[1];
                        texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                        vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);

                        texCoordArr << Vec2f(0.5f+xa/radius, 0.5f+ya/radius);
                        vertexArr << Vec3d(static_cast<double>(xa), static_cast<double>(ya), 0);
                        texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                        vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);

                        x = rad[i]*cos_sin_theta_p[0];
                        y = rad[i]*cos_sin_theta_p[1];
                        texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                        vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);
                }
        }
        // draw the inner polygon
        slices_step>>=1;
        cos_sin_theta_p=cos_sin_theta;

        if (slices==1)
        {
                x = rad[0]*cos_sin_theta_p[0];
                y = rad[0]*cos_sin_theta_p[1];
                texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);
                cos_sin_theta_p+=2*slices_step;
                x = rad[0]*cos_sin_theta_p[0];
                y = rad[0]*cos_sin_theta_p[1];
                texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);
                cos_sin_theta_p+=2*slices_step;
                x = rad[0]*cos_sin_theta_p[0];
                y = rad[0]*cos_sin_theta_p[1];
                texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);
        }
        else
        {
                j=0;
                while (j<slices)
                {
                        texCoordArr << Vec2f(0.5f, 0.5f);
                        vertexArr << Vec3d(0, 0, 0);
                        x = rad[0]*cos_sin_theta_p[0];
                        y = rad[0]*cos_sin_theta_p[1];
                        texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                        vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);
                        j+=slices_step;
                        cos_sin_theta_p+=2*slices_step;
                        x = rad[0]*cos_sin_theta_p[0];
                        y = rad[0]*cos_sin_theta_p[1];
                        texCoordArr << Vec2f(0.5f+x/radius, 0.5f+y/radius);
                        vertexArr << Vec3d(static_cast<double>(x), static_cast<double>(y), 0);
                }
        }
}

static void sSphereMapTexCoordFast(float rho_div_fov, const float costheta, const float sintheta, QVector<float>& out)
{
        if (rho_div_fov>0.5f)
                rho_div_fov=0.5f;
        out << 0.5f + rho_div_fov * costheta << 0.5f + rho_div_fov * sintheta;
}

void StelPainter::sSphereMap(double radius, unsigned int slices, unsigned int stacks, float textureFov, int orientInside)
{
        float rho;
        double x,y,z;
        unsigned int i, j;
        const float* cos_sin_rho = StelUtils::ComputeCosSinRho(stacks);
        const float* cos_sin_rho_p;

        const float* cos_sin_theta = StelUtils::ComputeCosSinTheta(slices);
        const float* cos_sin_theta_p;

        float drho = M_PIf / static_cast<float>(stacks);
        drho/=textureFov;

        // texturing: s goes from 0.0/0.25/0.5/0.75/1.0 at +y/+x/-y/-x/+y axis
        // t goes from -1.0/+1.0 at z = -radius/+radius (linear along longitudes)
        // cannot use triangle fan on texturing (s coord. at top/bottom tip varies)

        const unsigned int imax = stacks;

        static QVector<double> vertexArr;
        static QVector<float> texCoordArr;

        // draw intermediate stacks as quad strips
        // LGTM comments: the floats are always <=1. We still prefer float multiplication (with insignificant accuracy loss) for speed.
        if (!orientInside) // nsign==1
        {
                for (i = 0,cos_sin_rho_p=cos_sin_rho,rho=0.f; i < imax; ++i,cos_sin_rho_p+=2,rho+=drho)
                {
                        vertexArr.resize(0);
                        texCoordArr.resize(0);
                        for (j=0,cos_sin_theta_p=cos_sin_theta;j<=slices;++j,cos_sin_theta_p+=2)
                        {
                                x = static_cast<double>(-cos_sin_theta_p[1] * cos_sin_rho_p[1]);
                                y = static_cast<double>(cos_sin_theta_p[0] * cos_sin_rho_p[1]);
                                z = static_cast<double>(cos_sin_rho_p[0]);
                                sSphereMapTexCoordFast(rho, cos_sin_theta_p[0], cos_sin_theta_p[1], texCoordArr);
                                vertexArr << x*radius << y*radius << z*radius;

                                x = static_cast<double>(-cos_sin_theta_p[1] * cos_sin_rho_p[3]);
                                y = static_cast<double>(cos_sin_theta_p[0] * cos_sin_rho_p[3]);
                                z = static_cast<double>(cos_sin_rho_p[2]);
                                sSphereMapTexCoordFast(rho + drho, cos_sin_theta_p[0], cos_sin_theta_p[1], texCoordArr);
                                vertexArr << x*radius << y*radius << z*radius;
                        }
                        setArrays(reinterpret_cast<const Vec3d*>(vertexArr.constData()), reinterpret_cast<const Vec2f*>(texCoordArr.constData()));
                        drawFromArray(TriangleStrip, vertexArr.size()/3);
                }
        }
        else
        {
                for (i = 0,cos_sin_rho_p=cos_sin_rho,rho=0.f; i < imax; ++i,cos_sin_rho_p+=2,rho+=drho)
                {
                        vertexArr.resize(0);
                        texCoordArr.resize(0);
                        for (j=0,cos_sin_theta_p=cos_sin_theta;j<=slices;++j,cos_sin_theta_p+=2)
                        {
                                x = static_cast<double>(-cos_sin_theta_p[1] * cos_sin_rho_p[3]);
                                y = static_cast<double>(cos_sin_theta_p[0] * cos_sin_rho_p[3]);
                                z = static_cast<double>(cos_sin_rho_p[2]);
                                sSphereMapTexCoordFast(rho + drho, cos_sin_theta_p[0], -cos_sin_theta_p[1], texCoordArr);
                                vertexArr << x*radius << y*radius << z*radius;

                                x = static_cast<double>(-cos_sin_theta_p[1] * cos_sin_rho_p[1]);
                                y = static_cast<double>(cos_sin_theta_p[0] * cos_sin_rho_p[1]);
                                z = static_cast<double>(cos_sin_rho_p[0]);
                                sSphereMapTexCoordFast(rho, cos_sin_theta_p[0], -cos_sin_theta_p[1], texCoordArr);
                                vertexArr << x*radius << y*radius << z*radius;
                        }
                        setArrays(reinterpret_cast<const Vec3d*>(vertexArr.constData()), reinterpret_cast<const Vec2f*>(texCoordArr.constData()));
                        drawFromArray(TriangleStrip, vertexArr.size()/3);
                }
        }
}

void StelPainter::drawTextGravity180(float x, float y, const QString& ws, float xshift, float yshift)
{
        float dx, dy, d, theta, theta_o, psi, width;
        dx = x - static_cast<float>(prj->viewportCenter[0]);
        dy = y - static_cast<float>(prj->viewportCenter[1]);
        d = std::sqrt(dx*dx + dy*dy);
        float limit = 120.;

        // If the text is too far away to be visible in the screen return
        if (d>qMax(prj->viewportXywh[3], prj->viewportXywh[2])*2 || ws.isEmpty())
                return;

        float ppx = static_cast<float>(prj->getDevicePixelsPerPixel());
        float cWidth = static_cast<float>(getFontMetrics().boundingRect(ws).width())/ws.length();
        float stdWidth = static_cast<float>(getFontMetrics().boundingRect("a").width());
        theta = std::atan2(dy - 1, dx);
        theta_o = M_PIf + std::atan2(dx, dy - 1);        
        psi = std::atan2(ppx*cWidth, d + 1) * M_180_PIf;
        if (psi>5)
                psi = 5;

        float xVc = static_cast<float>(prj->viewportCenter[0]) + xshift;
        float yVc = static_cast<float>(prj->viewportCenter[1]) + yshift;
        const float cosr = std::cos(-theta_o * M_PI_180f);
        const float sinr = std::sin(-theta_o * M_PI_180f);
        float xom = x + xshift*cosr - yshift*sinr;
        float yom = y + yshift*sinr + yshift*cosr;

        if (!StelApp::getInstance().getLocaleMgr().isAppRTL())
        {
                for (int i=0; i<ws.length(); ++i)
                {
                        if (d<limit)
                        {
                                drawText(xom, yom, ws[i], -theta_o*M_180_PIf+psi*static_cast<float>(i), 0., 0.);
                                xom += cWidth*std::cos(-theta_o+psi*static_cast<float>(i) * M_PI_180f);
                                yom += cWidth*std::sin(-theta_o+psi*static_cast<float>(i) * M_PI_180f);
                        }
                        else
                        {
                                x = d * std::cos(theta) + xVc ;
                                y = d * std::sin(theta) + yVc ;
                                drawText(x, y, ws[i], 90.f + theta*M_180_PIf, 0., 0.);
                                // Compute how much the character contributes to the angle
                                if (ws[i].isSpace())
                                        width = stdWidth;
                                else
                                        width = static_cast<float>(getFontMetrics().boundingRect(ws[i]).width());
                                theta += psi * M_PI_180f * (1 + (width - cWidth)/ cWidth);
                        }
                }
        }
        else
        {
                int slen = ws.length();
                for (int i=0;i<slen;i++)
                {
                        if (d<limit)
                        {
                                drawText(xom, yom, ws[slen-1-i], -theta_o*M_180_PIf+psi*static_cast<float>(i), 0., 0.);
                                xom += cWidth*std::cos(-theta_o+psi*static_cast<float>(i) * M_PI_180f);
                                yom += cWidth*std::sin(-theta_o+psi*static_cast<float>(i) * M_PI_180f);
                        }
                        else
                        {
                                x = d * std::cos(theta) + xVc;
                                y = d * std::sin(theta) + yVc;
                                drawText(x, y, ws[slen-1-i], 90.f + theta*M_180_PIf, 0., 0.);
                                if (ws[slen-1-i].isSpace())
                                        width = stdWidth;
                                else
                                        width = static_cast<float>(getFontMetrics().boundingRect(ws[slen-1-i]).width());
                                theta += psi * M_PI_180f * (1 + (width - cWidth)/ cWidth);
                        }
                }
        }
}

void StelPainter::drawText(const Vec3d& v, const QString& str, float angleDeg, float xshift, float yshift, bool noGravity)
{
        Vec3d win;
        if (prj->project(v, win))
                drawText(static_cast<float>(win[0]), static_cast<float>(win[1]), str, angleDeg, xshift, yshift, noGravity);
}

/*************************************************************************
 Draw the string at the given position and angle with the given font
*************************************************************************/

// Methods taken from text-use-opengl-buffer
// Container for one cached string texture
struct StringTexture
{
        QOpenGLTexture* texture;
        QSize size;
        QSizeF getTexSize() const {
                return QSizeF(static_cast<qreal>(size.width())  / static_cast<qreal>(texture->width()),
                              static_cast<qreal>(size.height()) / static_cast<qreal>(texture->height()));
        }

        StringTexture(QOpenGLTexture* tex, const QSize& size) :
             texture(tex), size(size) {}
        ~StringTexture() {delete texture;}
};

StringTexture* StelPainter::getTexTexture(const QString& str, int pixelSize) const
{
        // Render first the text into a QPixmap, then create a QOpenGLTexture
        // from it.  We could optimize by directly using a QImage, but for some
        // reason the result is not exactly the same than with a QPixmap.
        QByteArray hash = str.toUtf8() + QByteArray::number(pixelSize);
        StringTexture* cachedTex = texCache.object(hash);
        if (cachedTex)
                return cachedTex;
        QFont tmpFont = currentFont;
        tmpFont.setPixelSize(currentFont.pixelSize()*static_cast<int>(static_cast<float>(prj->getDevicePixelsPerPixel())*StelApp::getInstance().getGlobalScalingRatio()));
        QRect strRect = QFontMetrics(tmpFont).boundingRect(str);
        int w = strRect.width()+1+static_cast<int>(0.02f*strRect.width());
        int h = strRect.height();

        QPixmap strImage = QPixmap(StelUtils::getBiggerPowerOfTwo(w), StelUtils::getBiggerPowerOfTwo(h));
        strImage.fill(Qt::transparent);
        QPainter painter(&strImage);
        tmpFont.setStyleStrategy(QFont::NoAntialias);
        painter.setFont(tmpFont);
        //painter.setRenderHints(QPainter::TextAntialiasing);
        painter.setPen(Qt::white);
        painter.drawText(-strRect.x(), -strRect.y(), str);
        StringTexture* newTex = new StringTexture(new QOpenGLTexture(strImage.toImage()), QSize(w, h));
        texCache.insert(hash, newTex, 3*w*h);
        // simply returning newTex is dangerous as the object is owned by the cache now. (Coverity Scan barks.)
        return texCache.object(hash);
}

void StelPainter::drawText(float x, float y, const QString& str, float angleDeg, float xshift, float yshift, bool noGravity)
{
        if (prj->gravityLabels && !noGravity)
        {
                drawTextGravity180(x, y, str, xshift, yshift);
        }
        else if (qApp->property("text_texture")==true) // CLI option -t given?
        {
                //qDebug() <<  "Text texture" << str;
                // This is taken from branch text-use-opengl-buffer. This is essential on devices like Raspberry Pi (2016-03).
                StringTexture* tex = getTexTexture(str, currentFont.pixelSize());
                Q_ASSERT(tex);
                if (!noGravity)
                        angleDeg += prj->defaultAngleForGravityText;
                tex->texture->bind();

                static float vertexData[8];
                // compute the vertex coordinates applying the translation and the rotation
                static const float vertexBase[] = {0., 0., 1., 0., 0., 1., 1., 1.};
                if (std::fabs(angleDeg)>1.f*M_PI_180f)
                {
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
                        const float cosr = std::cos(angleDeg * M_PI_180f);
                        const float sinr = std::sin(angleDeg * M_PI_180f);
                        for (int i = 0; i < 8; i+=2)
                        {
                                vertexData[i]   = int(x + (tex->size.width()*vertexBase[i]+xshift) * cosr - (tex->size.height()*vertexBase[i+1]+yshift) * sinr);
                                vertexData[i+1] = int(y + (tex->size.width()*vertexBase[i]+xshift) * sinr + (tex->size.height()*vertexBase[i+1]+yshift) * cosr);
                        }
                }
                else
                {
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
                        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
                        for (int i = 0; i < 8; i+=2)
                        {
                                vertexData[i]   = int(x + tex->size.width()*vertexBase[i]+xshift);
                                vertexData[i+1] = int(y + tex->size.height()*vertexBase[i+1]+yshift);
                        }
                }

                float* texCoords = new float[8];
                for (int i=0;i<4;i++)
                {
                        texCoords[i*2+0] = static_cast<float>(tex->getTexSize().width()) * (i % 2);
                        texCoords[i*2+1] = static_cast<float>(tex->getTexSize().height()) * (1 - static_cast<float>(i) / 2);
                }
                setTexCoordPointer(2, GL_FLOAT, texCoords);

                //text drawing requires blending, but we reset GL state afterwards if necessary
                bool oldBlending = glState.blend;
                GLenum oldSrc = glState.blendSrc, oldDst = glState.blendDst;
                setBlending(true);
                enableClientStates(true, true);
                setVertexPointer(2, GL_FLOAT, vertexData);
                drawFromArray(TriangleStrip, 4, 0, false);
                setBlending(oldBlending, oldSrc, oldDst);
                enableClientStates(false, false);
                tex->texture->release();
                delete[] texCoords;
        }
        else
        {
                QOpenGLPaintDevice device;
                device.setSize(QSize(prj->getViewportWidth(), prj->getViewportHeight()));
                // This doesn't seem to work correctly, so implement the hack below instead.
                // Maybe check again later, or check on mac with retina..
                // device.setDevicePixelRatio(prj->getDevicePixelsPerPixel());
                // painter.setFont(currentFont);
                
                QPainter painter(&device);
                
                QFont tmpFont = currentFont;
                tmpFont.setPixelSize(currentFont.pixelSize()*static_cast<int>(static_cast<float>(prj->getDevicePixelsPerPixel())*StelApp::getInstance().getGlobalScalingRatio()));
                painter.setFont(tmpFont);
                painter.setPen(currentColor.toQColor());
                
                float scaleRatio = StelApp::getInstance().getGlobalScalingRatio();
                xshift*=scaleRatio;
                yshift*=scaleRatio;
                
                y = prj->getViewportHeight()-y;
                yshift = -yshift;

                // Translate/rotate
                if (!noGravity)
                        angleDeg += prj->defaultAngleForGravityText;

                if (std::fabs(angleDeg)>1.f)
                {
                        QTransform m;
                        m.translate(static_cast<qreal>(x), static_cast<qreal>(y));
                        m.rotate(static_cast<qreal>(-angleDeg));
                        painter.setTransform(m);
                        painter.drawText(qRound(xshift), qRound(yshift), str);
                }
                else
                {
                        painter.drawText(qRound(x+xshift), qRound(y+yshift), str);
                }
                
                //important to call this before GL state restore
                painter.end();

                //fix for bug 1628072 caused by QTBUG-56798
#ifndef QT_NO_DEBUG
                StelOpenGL::clearGLErrors();
#endif

                //QPainter messes up some GL state, begin/endNativePainting or save/restore does not help
                glState.apply();
        }
}

// Recursive method cutting a small circle in small segments
inline void fIter(const StelProjectorP& prj, const Vec3d& p1, const Vec3d& p2, Vec3d& win1, Vec3d& win2, std::list<Vec3d>& vertexList, const std::list<Vec3d>::const_iterator& iter, double radius, const Vec3d& center, int nbI=0, bool checkCrossDiscontinuity=true)
{
        const bool crossDiscontinuity = checkCrossDiscontinuity && prj->intersectViewportDiscontinuity(p1+center, p2+center);
        if (crossDiscontinuity && nbI>=10)
        {
                win1[2]=-2.;
                win2[2]=-2.;
                vertexList.insert(iter, win1);
                vertexList.insert(iter, win2);
                return;
        }

        Vec3d newVertex(p1); newVertex+=p2;
        newVertex.normalize();
        newVertex*=radius;
        Vec3d win3(newVertex[0]+center[0], newVertex[1]+center[1], newVertex[2]+center[2]);
        const bool isValidVertex = prj->projectInPlace(win3);

        const float v10=static_cast<float>(win1[0]-win3[0]);
        const float v11=static_cast<float>(win1[1]-win3[1]);
        const float v20=static_cast<float>(win2[0]-win3[0]);
        const float v21=static_cast<float>(win2[1]-win3[1]);

        const float dist = std::sqrt((v10*v10+v11*v11)*(v20*v20+v21*v21));
        const float cosAngle = (v10*v20+v11*v21)/dist;
        if ((cosAngle>-0.999f || dist>50*50 || crossDiscontinuity) && nbI<10)
        {
                // Use the 3rd component of the vector to store whether the vertex is valid
                win3[2]= isValidVertex ? 1.0 : -1.;
                fIter(prj, p1, newVertex, win1, win3, vertexList, vertexList.insert(iter, win3), radius, center, nbI+1, crossDiscontinuity || dist>50*50);
                fIter(prj, newVertex, p2, win3, win2, vertexList, iter, radius, center, nbI+1, crossDiscontinuity || dist>50*50 );
        }
}

// Used by the method below
QVector<Vec3f> StelPainter::smallCircleVertexArray;
QVector<Vec4f> StelPainter::smallCircleColorArray;

void StelPainter::drawSmallCircleVertexArray()
{
        if (smallCircleVertexArray.size() == 1)
        {
                smallCircleVertexArray.resize(0);
                smallCircleColorArray.resize(0);
                return;
        }
        if (smallCircleVertexArray.isEmpty())
                return;

        enableClientStates(true, false, !smallCircleColorArray.isEmpty());
        setVertexPointer(3, GL_FLOAT, smallCircleVertexArray.constData());
        if (!smallCircleColorArray.isEmpty())
                setColorPointer(4, GL_FLOAT, smallCircleColorArray.constData());
        drawFromArray(LineStrip, smallCircleVertexArray.size(), 0, false);
        enableClientStates(false);
        smallCircleVertexArray.resize(0);
        smallCircleColorArray.resize(0);
}

void StelPainter::drawGreatCircleArc(const Vec3d& start, const Vec3d& stop, const SphericalCap* clippingCap,
        void (*viewportEdgeIntersectCallback)(const Vec3d& screenPos, const Vec3d& direction, void* userData), void* userData)
 {
         if (clippingCap)
         {
                 Vec3d pt1=start;
                 Vec3d pt2=stop;
                 if (clippingCap->clipGreatCircle(pt1, pt2))
                 {
                        drawSmallCircleArc(pt1, pt2, Vec3d(0.), viewportEdgeIntersectCallback, userData);
                 }
                 return;
        }
        drawSmallCircleArc(start, stop, Vec3d(0.), viewportEdgeIntersectCallback, userData);
 }

/*************************************************************************
 Draw a small circle arc in the current frame
*************************************************************************/
void StelPainter::drawSmallCircleArc(const Vec3d& start, const Vec3d& stop, const Vec3d& rotCenter, void (*viewportEdgeIntersectCallback)(const Vec3d& screenPos, const Vec3d& direction, void* userData), void* userData)
{
        Q_ASSERT(smallCircleVertexArray.empty());

        std::list<Vec3d> tessArc;        // Contains the list of projected points from the tesselated arc. (QLinkedList no longer available in Qt6.)
        Vec3d win1, win2;
        win1[2] = prj->project(start, win1) ? 1.0 : -1.;
        win2[2] = prj->project(stop, win2) ? 1.0 : -1.;
        tessArc.push_back(win1);


        if (rotCenter.normSquared()<1e-11)
        {
                // Great circle
                // Perform the tesselation of the arc in small segments in a way so that the lines look smooth
                fIter(prj, start, stop, win1, win2, tessArc, tessArc.insert(tessArc.end(), win2), 1, rotCenter);
        }
        else
        {
                Vec3d tmp = (rotCenter^start)/rotCenter.norm();
                const double radius = fabs(tmp.norm());
                // Perform the tesselation of the arc in small segments in a way so that the lines look smooth
                fIter(prj, start-rotCenter, stop-rotCenter, win1, win2, tessArc, tessArc.insert(tessArc.end(), win2), radius, rotCenter);
        }

        // And draw.
        std::list<Vec3d>::const_iterator i = tessArc.cbegin();
        //while (i<tessArc.cend())
        while (std::next(i, 1) != tessArc.cend())
        {
                const Vec3d& p1 = *i;
                const Vec3d& p2 = *(++i);
                const bool p1InViewport = prj->checkInViewport(p1);
                const bool p2InViewport = prj->checkInViewport(p2);
                if ((p1[2]>0 && p1InViewport) || (p2[2]>0 && p2InViewport))
                {
                        smallCircleVertexArray.append(p1.toVec3f()); //Vec3f(static_cast<float>(p1[0]), static_cast<float>(p1[1]), static_cast<float>(p1[2])));
                        if (std::next(i,1)==tessArc.cend())
                        {
                                smallCircleVertexArray.append(p2.toVec3f()); //Vec3f(static_cast<float>(p2[0]), static_cast<float>(p2[1]), static_cast<float>(p2[2])));
                                drawSmallCircleVertexArray();
                        }
                        if (viewportEdgeIntersectCallback && p1InViewport!=p2InViewport)
                        {
                                // We crossed the edge of the view port
                                if (p1InViewport)
                                        viewportEdgeIntersectCallback(prj->viewPortIntersect(p1, p2), p2-p1, userData);
                                else
                                        viewportEdgeIntersectCallback(prj->viewPortIntersect(p2, p1), p1-p2, userData);
                        }
                }
                else
                {
                        // Break the line, draw the stored vertex and flush the list
                        if (!smallCircleVertexArray.isEmpty())
                                smallCircleVertexArray.append(Vec3f(static_cast<float>(p1[0]), static_cast<float>(p1[1]), static_cast<float>(p1[2])));
                        drawSmallCircleVertexArray();
                }
        }
        Q_ASSERT(smallCircleVertexArray.isEmpty());
}

void StelPainter::drawPath(const QVector<Vec3d> &points, const QVector<Vec4f> &colors)
{
        // Because the path may intersect a viewport discontinuity, we cannot render
        // it in one OpenGL drawing call.
        Q_ASSERT(smallCircleVertexArray.isEmpty());
        Q_ASSERT(smallCircleColorArray.isEmpty());
        Q_ASSERT(points.size() == colors.size());
        Vec3d win;

        // In general we should add all the points, even if they are hidden, since otherwise we don't
        // have proper clipping on the sides.  We make an exception for the orthographic projection because
        // its clipping doesn't work well.  A better solution would be to use a culling test I think.
        bool skipHiddenPoints = dynamic_cast<StelProjectorOrthographic*>(prj.data());

        for (int i = 0; i+1 != points.size(); i++)
        {
                const Vec3d p1 = points[i];
                const Vec3d p2 = points[i + 1];
                if (!prj->intersectViewportDiscontinuity(p1, p2))
                {
                        bool visible = prj->project(p1, win);

                        if (!visible && skipHiddenPoints)
                        {
                                drawSmallCircleVertexArray();
                                continue;
                        }

                        smallCircleVertexArray.append(Vec3f(static_cast<float>(win[0]), static_cast<float>(win[1]), static_cast<float>(win[2])));
                        smallCircleColorArray.append(colors[i]);
                        if (i+2==points.size())
                        {
                                prj->project(p2, win);
                                smallCircleVertexArray.append(Vec3f(static_cast<float>(win[0]), static_cast<float>(win[1]), static_cast<float>(win[2])));
                                smallCircleColorArray.append(colors[i + 1]);
                                drawSmallCircleVertexArray();
                        }
                }
                else
                {
                        // Break the line, draw the stored vertex and flush the list
                        if (!smallCircleVertexArray.isEmpty())
                        {
                                prj->project(p1, win);
                                smallCircleVertexArray.append(Vec3f(static_cast<float>(win[0]), static_cast<float>(win[1]), static_cast<float>(win[2])));
                                smallCircleColorArray.append(colors[i]);
                        }
                        drawSmallCircleVertexArray();
                }
        }
        Q_ASSERT(smallCircleVertexArray.isEmpty());
        Q_ASSERT(smallCircleColorArray.isEmpty());
}

// Project the passed triangle on the screen ensuring that it will look smooth, even for non linear distortion
// by splitting it into subtriangles.
void StelPainter::projectSphericalTriangle(const SphericalCap* clippingCap, const Vec3d* vertices, QVarLengthArray<Vec3f, 4096>* outVertices,
        const Vec2f* texturePos, QVarLengthArray<Vec2f, 4096>* outTexturePos, const Vec3f *colors, QVarLengthArray<Vec3f, 4096> *outColors,
        double maxSqDistortion, int nbI, bool checkDisc1, bool checkDisc2, bool checkDisc3) const
{
        Q_ASSERT(fabs(vertices[0].norm()-1.)<0.00001);
        Q_ASSERT(fabs(vertices[1].norm()-1.)<0.00001);
        Q_ASSERT(fabs(vertices[2].norm()-1.)<0.00001);
        if (clippingCap && clippingCap->containsTriangle(vertices))
                clippingCap = Q_NULLPTR;
        if (clippingCap && !clippingCap->intersectsTriangle(vertices))
                return;
        bool cDiscontinuity1 = checkDisc1 && prj->intersectViewportDiscontinuity(vertices[0], vertices[1]);
        bool cDiscontinuity2 = checkDisc2 && prj->intersectViewportDiscontinuity(vertices[1], vertices[2]);
        bool cDiscontinuity3 = checkDisc3 && prj->intersectViewportDiscontinuity(vertices[0], vertices[2]);
        const bool cd1=cDiscontinuity1;
        const bool cd2=cDiscontinuity2;
        const bool cd3=cDiscontinuity3;

        Vec3d e0=vertices[0];
        Vec3d e1=vertices[1];
        Vec3d e2=vertices[2];
        bool valid = prj->projectInPlace(e0);
        valid = prj->projectInPlace(e1) || valid;
        valid = prj->projectInPlace(e2) || valid;
        // Clip polygons behind the viewer
        if (!valid)
                return;

        if (checkDisc1 && cDiscontinuity1==false)
        {
                // If the distortion at segment e0,e1 is too big, flags it for subdivision
                Vec3d win3 = vertices[0]; win3+=vertices[1];
                prj->projectInPlace(win3);
                win3[0]-=(e0[0]+e1[0])*0.5; win3[1]-=(e0[1]+e1[1])*0.5;
                cDiscontinuity1 = (win3[0]*win3[0]+win3[1]*win3[1])>maxSqDistortion;
        }
        if (checkDisc2 && cDiscontinuity2==false)
        {
                // If the distortion at segment e1,e2 is too big, flags it for subdivision
                Vec3d win3 = vertices[1]; win3+=vertices[2];
                prj->projectInPlace(win3);
                win3[0]-=(e2[0]+e1[0])*0.5; win3[1]-=(e2[1]+e1[1])*0.5;
                cDiscontinuity2 = (win3[0]*win3[0]+win3[1]*win3[1])>maxSqDistortion;
        }
        if (checkDisc3 && cDiscontinuity3==false)
        {
                // If the distortion at segment e2,e0 is too big, flags it for subdivision
                Vec3d win3 = vertices[2]; win3+=vertices[0];
                prj->projectInPlace(win3);
                win3[0] -= (e0[0]+e2[0])*0.5;
                win3[1] -= (e0[1]+e2[1])*0.5;
                cDiscontinuity3 = (win3[0]*win3[0]+win3[1]*win3[1])>maxSqDistortion;
        }

        if (!cDiscontinuity1 && !cDiscontinuity2 && !cDiscontinuity3)
        {
                // The triangle is clean, appends it
                outVertices->append(e0.toVec3f()); outVertices->append(e1.toVec3f()); outVertices->append(e2.toVec3f());
                if (outTexturePos)
                        outTexturePos->append(texturePos,3);
                if (outColors)
                        outColors->append(colors,3);
                return;
        }

        if (nbI > 4)
        {
                // If we reached the limit number of iterations and still have a discontinuity,
                // discards the triangle.
                if (cd1 || cd2 || cd3)
                        return;

                // Else display it, it will be suboptimal though.
                outVertices->append(e0.toVec3f()); outVertices->append(e1.toVec3f()); outVertices->append(e2.toVec3f());
                if (outTexturePos)
                        outTexturePos->append(texturePos,3);
                if (outColors)
                        outColors->append(colors,3);
                return;
        }

        // Recursively splits the triangle into sub triangles.
        // Depending on which combination of sides of the triangle has to be split a different strategy is used.
        Vec3d va[3];
        Vec2f ta[3];
        Vec3f ca[3];
        // Only 1 side has to be split: split the triangle in 2
        if (cDiscontinuity1 && !cDiscontinuity2 && !cDiscontinuity3)
        {
                va[0]=vertices[0];
                va[1]=vertices[0];va[1]+=vertices[1];
                va[1].normalize();
                va[2]=vertices[2];
                if (outTexturePos)
                {
                        ta[0]=texturePos[0];
                        ta[1]=(texturePos[0]+texturePos[1])*0.5;
                        ta[2]=texturePos[2];
                }
                if (outColors)
                {
                        ca[0]=colors[0];
                        ca[1]=(colors[0]+colors[1])*0.5;
                        ca[2]=colors[2];
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1, true, true, false);

                //va[0]=vertices[0]+vertices[1];
                //va[0].normalize();
                va[0]=va[1];
                va[1]=vertices[1];
                va[2]=vertices[2];
                if (outTexturePos)
                {
                        ta[0]=(texturePos[0]+texturePos[1])*0.5;
                        ta[1]=texturePos[1];
                        ta[2]=texturePos[2];
                }
                if (outColors)
                {
                        ca[0]=(colors[0]+colors[1])*0.5;
                        ca[1]=colors[1];
                        ca[2]=colors[2];
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1, true, false, true);
                return;
        }

        if (!cDiscontinuity1 && cDiscontinuity2 && !cDiscontinuity3)
        {
                va[0]=vertices[0];
                va[1]=vertices[1];
                va[2]=vertices[1];va[2]+=vertices[2];
                va[2].normalize();
                if (outTexturePos)
                {
                        ta[0]=texturePos[0];
                        ta[1]=texturePos[1];
                        ta[2]=(texturePos[1]+texturePos[2])*0.5;
                }
                if (outColors)
                {
                        ca[0]=colors[0];
                        ca[1]=colors[1];
                        ca[2]=(colors[1]+colors[2])*0.5;
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1, false, true, true);

                va[0]=vertices[0];
                //va[1]=vertices[1]+vertices[2];
                //va[1].normalize();
                va[1]=va[2];
                va[2]=vertices[2];
                if (outTexturePos)
                {
                        ta[0]=texturePos[0];
                        ta[1]=(texturePos[1]+texturePos[2])*0.5;
                        ta[2]=texturePos[2];
                }
                if (outColors)
                {
                        ca[0]=colors[0];
                        ca[1]=(colors[1]+colors[2])*0.5;
                        ca[2]=colors[2];
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1, true, true, false);
                return;
        }

        if (!cDiscontinuity1 && !cDiscontinuity2 && cDiscontinuity3)
        {
                va[0]=vertices[0];
                va[1]=vertices[1];
                va[2]=vertices[0];va[2]+=vertices[2];
                va[2].normalize();
                if (outTexturePos)
                {
                        ta[0]=texturePos[0];
                        ta[1]=texturePos[1];
                        ta[2]=(texturePos[0]+texturePos[2])*0.5;
                }
                if (outColors)
                {
                        ca[0]=colors[0];
                        ca[1]=colors[1];
                        ca[2]=(colors[0]+colors[2])*0.5;
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1, false, true, true);

                //va[0]=vertices[0]+vertices[2];
                //va[0].normalize();
                va[0]=va[2];
                va[1]=vertices[1];
                va[2]=vertices[2];
                if (outTexturePos)
                {
                        ta[0]=(texturePos[0]+texturePos[2])*0.5;
                        ta[1]=texturePos[1];
                        ta[2]=texturePos[2];
                }
                if (outColors)
                {
                        ca[0]=(colors[0]+colors[2])*0.5;
                        ca[1]=colors[1];
                        ca[2]=colors[2];
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1, true, false, true);
                return;
        }

        // 2 sides have to be split: split the triangle in 3
        if (cDiscontinuity1 && cDiscontinuity2 && !cDiscontinuity3)
        {
                va[0]=vertices[0];
                va[1]=vertices[0];va[1]+=vertices[1];
                va[1].normalize();
                va[2]=vertices[1];va[2]+=vertices[2];
                va[2].normalize();
                if (outTexturePos)
                {
                        ta[0]=texturePos[0];
                        ta[1]=(texturePos[0]+texturePos[1])*0.5;
                        ta[2]=(texturePos[1]+texturePos[2])*0.5;
                }
                if (outColors)
                {
                        ca[0]=colors[0];
                        ca[1]=(colors[0]+colors[1])*0.5;
                        ca[2]=(colors[1]+colors[2])*0.5;
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);

                //va[0]=vertices[0]+vertices[1];
                //va[0].normalize();
                va[0]=va[1];
                va[1]=vertices[1];
                //va[2]=vertices[1]+vertices[2];
                //va[2].normalize();
                if (outTexturePos)
                {
                        ta[0]=(texturePos[0]+texturePos[1])*0.5;
                        ta[1]=texturePos[1];
                        ta[2]=(texturePos[1]+texturePos[2])*0.5;
                }
                if (outColors)
                {
                        ca[0]=(colors[0]+colors[1])*0.5;
                        ca[1]=colors[1];
                        ca[2]=(colors[1]+colors[2])*0.5;
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);

                va[0]=vertices[0];
                //va[1]=vertices[1]+vertices[2];
                //va[1].normalize();
                va[1]=va[2];
                va[2]=vertices[2];
                if (outTexturePos)
                {
                        ta[0]=texturePos[0];
                        ta[1]=(texturePos[1]+texturePos[2])*0.5;
                        ta[2]=texturePos[2];
                }
                if (outColors)
                {
                        ca[0]=colors[0];
                        ca[1]=(colors[1]+colors[2])*0.5;
                        ca[2]=colors[2];
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1, true, true, false);
                return;
        }
        if (cDiscontinuity1 && !cDiscontinuity2 && cDiscontinuity3)
        {
                va[0]=vertices[0];
                va[1]=vertices[0];va[1]+=vertices[1];
                va[1].normalize();
                va[2]=vertices[0];va[2]+=vertices[2];
                va[2].normalize();
                if (outTexturePos)
                {
                        ta[0]=texturePos[0];
                        ta[1]=(texturePos[0]+texturePos[1])*0.5;
                        ta[2]=(texturePos[0]+texturePos[2])*0.5;
                }
                if (outColors)
                {
                        ca[0]=colors[0];
                        ca[1]=(colors[0]+colors[1])*0.5;
                        ca[2]=(colors[0]+colors[2])*0.5;
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);

                //va[0]=vertices[0]+vertices[1];
                //va[0].normalize();
                va[0]=va[1];
                va[1]=vertices[2];
                //va[2]=vertices[0]+vertices[2];
                //va[2].normalize();
                if (outTexturePos)
                {
                        ta[0]=(texturePos[0]+texturePos[1])*0.5;
                        ta[1]=texturePos[2];
                        ta[2]=(texturePos[0]+texturePos[2])*0.5;
                }
                if (outColors)
                {
                        ca[0]=(colors[0]+colors[1])*0.5;
                        ca[1]=colors[2];
                        ca[2]=(colors[0]+colors[2])*0.5;
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);


                //va[0]=vertices[0]+vertices[1];
                //va[0].normalize();
                va[1]=vertices[1];
                va[2]=vertices[2];
                if (outTexturePos)
                {
                        ta[0]=(texturePos[0]+texturePos[1])*0.5;
                        ta[1]=texturePos[1];
                        ta[2]=texturePos[2];
                }
                if (outColors)
                {
                        ca[0]=(colors[0]+colors[1])*0.5;
                        ca[1]=colors[1];
                        ca[2]=colors[2];
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1, true, false, true);

                return;
        }
        if (!cDiscontinuity1 && cDiscontinuity2 && cDiscontinuity3)
        {
                va[0]=vertices[0];
                va[1]=vertices[1];
                va[2]=vertices[1];va[2]+=vertices[2];
                va[2].normalize();
                if (outTexturePos)
                {
                        ta[0]=texturePos[0];
                        ta[1]=texturePos[1];
                        ta[2]=(texturePos[1]+texturePos[2])*0.5;
                }
                if (outColors)
                {
                        ca[0]=colors[0];
                        ca[1]=colors[1];
                        ca[2]=(colors[1]+colors[2])*0.5;
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1, false, true, true);

                //va[0]=vertices[1]+vertices[2];
                //va[0].normalize();
                va[0]=va[2];
                va[1]=vertices[2];
                va[2]=vertices[0];va[2]+=vertices[2];
                va[2].normalize();
                if (outTexturePos)
                {
                        ta[0]=(texturePos[1]+texturePos[2])*0.5;
                        ta[1]=texturePos[2];
                        ta[2]=(texturePos[0]+texturePos[2])*0.5;
                }
                if (outColors)
                {
                        ca[0]=(colors[1]+colors[2])*0.5;
                        ca[1]=colors[2];
                        ca[2]=(colors[0]+colors[2])*0.5;
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);

                va[1]=va[0];
                va[0]=vertices[0];
                //va[1]=vertices[1]+vertices[2];
                //va[1].normalize();
                //va[2]=vertices[0]+vertices[2];
                //va[2].normalize();
                if (outTexturePos)
                {
                        ta[0]=texturePos[0];
                        ta[1]=(texturePos[1]+texturePos[2])*0.5;
                        ta[2]=(texturePos[0]+texturePos[2])*0.5;
                }
                if (outColors)
                {
                        ca[0]=colors[0];
                        ca[1]=(colors[1]+colors[2])*0.5;
                        ca[2]=(colors[0]+colors[2])*0.5;
                }
                projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);
                return;
        }

        // Last case: the 3 sides have to be split: cut in 4 triangles a' la HTM
        va[0]=vertices[0];va[0]+=vertices[1];
        va[0].normalize();
        va[1]=vertices[1];va[1]+=vertices[2];
        va[1].normalize();
        va[2]=vertices[0];va[2]+=vertices[2];
        va[2].normalize();
        if (outTexturePos)
        {
                ta[0]=(texturePos[0]+texturePos[1])*0.5;
                ta[1]=(texturePos[1]+texturePos[2])*0.5;
                ta[2]=(texturePos[0]+texturePos[2])*0.5;
        }
        if (outColors)
        {
                ca[0]=(colors[0]+colors[1])*0.5;
                ca[1]=(colors[1]+colors[2])*0.5;
                ca[2]=(colors[0]+colors[2])*0.5;
        }
        projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);

        va[1]=va[0];
        va[0]=vertices[0];
        //va[1]=vertices[0]+vertices[1];
        //va[1].normalize();
        //va[2]=vertices[0]+vertices[2];
        //va[2].normalize();
        if (outTexturePos)
        {
                ta[0]=texturePos[0];
                ta[1]=(texturePos[0]+texturePos[1])*0.5;
                ta[2]=(texturePos[0]+texturePos[2])*0.5;
        }
        if (outColors)
        {
                ca[0]=colors[0];
                ca[1]=(colors[0]+colors[1])*0.5;
                ca[2]=(colors[0]+colors[2])*0.5;
        }
        projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);

        //va[0]=vertices[0]+vertices[1];
        //va[0].normalize();
        va[0]=va[1];
        va[1]=vertices[1];
        va[2]=vertices[1];va[2]+=vertices[2];
        va[2].normalize();
        if (outTexturePos)
        {
                ta[0]=(texturePos[0]+texturePos[1])*0.5;
                ta[1]=texturePos[1];
                ta[2]=(texturePos[1]+texturePos[2])*0.5;
        }
        if (outColors)
        {
                ca[0]=(colors[0]+colors[1])*0.5;
                ca[1]=colors[1];
                ca[2]=(colors[1]+colors[2])*0.5;
        }
        projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);

        va[0]=vertices[0];va[0]+=vertices[2];
        va[0].normalize();
        //va[1]=vertices[1]+vertices[2];
        //va[1].normalize();
        va[1]=va[2];
        va[2]=vertices[2];
        if (outTexturePos)
        {
                ta[0]=(texturePos[0]+texturePos[2])*0.5;
                ta[1]=(texturePos[1]+texturePos[2])*0.5;
                ta[2]=texturePos[2];
        }
        if (outColors)
        {
                ca[0]=(colors[0]+colors[2])*0.5;
                ca[1]=(colors[1]+colors[2])*0.5;
                ca[2]=colors[2];
        }
        projectSphericalTriangle(clippingCap, va, outVertices, ta, outTexturePos, ca, outColors, maxSqDistortion, nbI+1);

        return;
}

static QVarLengthArray<Vec3f, 4096> polygonVertexArray;
static QVarLengthArray<Vec2f, 4096> polygonTextureCoordArray;
static QVarLengthArray<Vec3f, 4096> polygonColorArray;
static QVarLengthArray<unsigned int, 4096> indexArray;

void StelPainter::drawGreatCircleArcs(const StelVertexArray& va, const SphericalCap* clippingCap)
{
        Q_ASSERT(va.vertex.size()!=1);
        Q_ASSERT(!va.isIndexed());        // Indexed unsupported yet
        switch (va.primitiveType)
        {
                case StelVertexArray::Lines:
                        Q_ASSERT(va.vertex.size()%2==0);
                        for (int i=0;i<va.vertex.size();i+=2)
                                drawGreatCircleArc(va.vertex.at(i), va.vertex.at(i+1), clippingCap);
                        return;
                case StelVertexArray::LineStrip:
                        for (int i=0;i<va.vertex.size()-1;++i)
                                drawGreatCircleArc(va.vertex.at(i), va.vertex.at(i+1), clippingCap);
                        return;
                case StelVertexArray::LineLoop:
                        for (int i=0;i<va.vertex.size()-1;++i)
                                drawGreatCircleArc(va.vertex.at(i), va.vertex.at(i+1), clippingCap);
                        drawGreatCircleArc(va.vertex.last(), va.vertex.first(), clippingCap);
                        return;
                default:
                        Q_ASSERT(0); // Unsupported primitive yype
        }
}

// The function object that we use as an interface between VertexArray::foreachTriangle and
// StelPainter::projectSphericalTriangle.
//
// This is used by drawSphericalTriangles to project all the triangles coordinates in a StelVertexArray into our global
// vertex array buffer.
class VertexArrayProjector
{
public:
        VertexArrayProjector(const StelVertexArray& ar, StelPainter* apainter, const SphericalCap* aclippingCap,
                                                 QVarLengthArray<Vec3f, 4096>* aoutVertices, QVarLengthArray<Vec2f, 4096>* aoutTexturePos=Q_NULLPTR, QVarLengthArray<Vec3f, 4096>* aoutColors=Q_NULLPTR, double amaxSqDistortion=5.)
                   : //vertexArray(ar),
                     painter(apainter), clippingCap(aclippingCap), outVertices(aoutVertices),
                         outColors(aoutColors), outTexturePos(aoutTexturePos), maxSqDistortion(amaxSqDistortion)
        {
                Q_UNUSED(ar)
        }

        // Project a single triangle and add it into the output arrays
        inline void operator()(const Vec3d* v0, const Vec3d* v1, const Vec3d* v2,
                                                   const Vec2f* t0, const Vec2f* t1, const Vec2f* t2,
                                                   const Vec3f* c0, const Vec3f* c1, const Vec3f* c2,
                                                   unsigned int, unsigned int, unsigned) const
        {
                // XXX: we may optimize more by putting the declaration and the test outside of this method.
                Vec3d tmpVertex[3] = {*v0, *v1, *v2};
                // required, else assertion at begin of projectSphericalTriangle() fails!
                tmpVertex[0].normalize();
                tmpVertex[1].normalize();
                tmpVertex[2].normalize();
                if ( (outTexturePos) && (outColors))
                {
                        const Vec2f tmpTexture[3] = {*t0, *t1, *t2};
                        const Vec3f tmpColor[3] = {*c0, *c1, *c2};
                        painter->projectSphericalTriangle(clippingCap, tmpVertex, outVertices, tmpTexture, outTexturePos, tmpColor, outColors, maxSqDistortion);
                }
                else if (outTexturePos)
                {
                        const Vec2f tmpTexture[3] = {*t0, *t1, *t2};
                        painter->projectSphericalTriangle(clippingCap, tmpVertex, outVertices, tmpTexture, outTexturePos, Q_NULLPTR, Q_NULLPTR, maxSqDistortion);
                }
                else if (outColors)
                {
                        const Vec3f tmpColor[3] = {*c0, *c1, *c2};
                        painter->projectSphericalTriangle(clippingCap, tmpVertex, outVertices, Q_NULLPTR, Q_NULLPTR, tmpColor, outColors, maxSqDistortion);
                }
                else
                        painter->projectSphericalTriangle(clippingCap, tmpVertex, outVertices, Q_NULLPTR, Q_NULLPTR, Q_NULLPTR, Q_NULLPTR, maxSqDistortion);
        }

        // Draw the resulting arrays
        void drawResult()
        {
                painter->setVertexPointer(3, GL_FLOAT, outVertices->constData());
                if (outTexturePos)
                        painter->setTexCoordPointer(2, GL_FLOAT, outTexturePos->constData());
                if (outColors)
                        painter->setColorPointer(3, GL_FLOAT, outColors->constData());

                painter->enableClientStates(true, outTexturePos != Q_NULLPTR, outColors != Q_NULLPTR);
                painter->drawFromArray(StelPainter::Triangles, outVertices->size(), 0, false);
                painter->enableClientStates(false);
        }

private:
        StelPainter* painter;
        const SphericalCap* clippingCap;
        QVarLengthArray<Vec3f, 4096>* outVertices;
        QVarLengthArray<Vec3f, 4096>* outColors;
        QVarLengthArray<Vec2f, 4096>* outTexturePos;
        double maxSqDistortion;
};

void StelPainter::drawStelVertexArray(const StelVertexArray& arr, bool checkDiscontinuity, Vec3d aberration)
{
        if (checkDiscontinuity && prj->hasDiscontinuity())
        {
                // The projection has discontinuities, so we need to make sure that no triangle is crossing them.
                drawStelVertexArray(arr.removeDiscontinuousTriangles(this->getProjector().data()), false, aberration);
                return;
        }

        if (aberration==Vec3d(0.))
        {
                setVertexPointer(3, GL_DOUBLE, arr.vertex.constData());
        }
        else
        {
                QVector<Vec3d> aberredVertex(arr.vertex.size());
                for (int i=0; i<arr.vertex.size(); i++)
                {
                        Q_ASSERT(qFuzzyCompare(arr.vertex.at(i).normSquared(), 1.0));
                        Vec3d vec=arr.vertex.at(i)+aberration;
                        vec.normalize();
                        aberredVertex[i]=vec;
                }
                setVertexPointer(3, GL_DOUBLE, aberredVertex.constData());
        }
        if (arr.isTextured())
        {
                setTexCoordPointer(2, GL_FLOAT, arr.texCoords.constData());
                if (arr.isColored())
                {
                        setColorPointer(3, GL_FLOAT, arr.colors.constData());
                        enableClientStates(true, true, true);
                }
                else
                        enableClientStates(true, true, false);
        }
        else
        {
                if (arr.isColored())
                {
                        setColorPointer(3, GL_FLOAT, arr.colors.constData());
                        enableClientStates(true, false, true);
                }
                else
                        enableClientStates(true, false, false);
        }
        if (arr.isIndexed())
                drawFromArray(static_cast<StelPainter::DrawingMode>(arr.primitiveType), arr.indices.size(), 0, true, arr.indices.constData());
        else
                drawFromArray(static_cast<StelPainter::DrawingMode>(arr.primitiveType), arr.vertex.size());

        enableClientStates(false);
}

void StelPainter::drawSphericalTriangles(const StelVertexArray& va, bool textured, bool colored, const SphericalCap* clippingCap, bool doSubDivide, double maxSqDistortion)
{
        if (va.vertex.isEmpty())
                return;

        Q_ASSERT(va.vertex.size()>2);
        polygonVertexArray.clear();
        polygonTextureCoordArray.clear();

        indexArray.clear();

        if (!doSubDivide)
        {
                // The simplest case, we don't need to iterate through the triangles at all.
                drawStelVertexArray(va);
                return;
        }

        // the last case.  It is the slowest, it process the triangles one by one.
        {
                // Project all the triangles of the VertexArray into our buffer arrays.
                VertexArrayProjector result = va.foreachTriangle(VertexArrayProjector(va, this, clippingCap, &polygonVertexArray, textured ? &polygonTextureCoordArray : Q_NULLPTR, colored ? &polygonColorArray : Q_NULLPTR, maxSqDistortion));
                result.drawResult();
                return;
        }
}

// Draw the given SphericalPolygon.
void StelPainter::drawSphericalRegion(SphericalRegion* poly, SphericalPolygonDrawMode drawMode, const SphericalCap* clippingCap, const bool doSubDivise, const double maxSqDistortion, const Vec3d &observerVelocity)
{
        if (!prj->getBoundingCap().intersects(poly->getBoundingCap()))
                return;

        bool oldCullFace = glState.cullFace;

        switch (drawMode)
        {
                case SphericalPolygonDrawModeBoundary:
                        if (doSubDivise || prj->intersectViewportDiscontinuity(poly->getBoundingCap()))
                                drawGreatCircleArcs(poly->getOutlineVertexArray(), clippingCap);
                        else
                                drawStelVertexArray(poly->getOutlineVertexArray(), false);
                        break;
                case SphericalPolygonDrawModeFill:
                case SphericalPolygonDrawModeTextureFill:
                case SphericalPolygonDrawModeTextureFillColormodulated:
                        setCullFace(true);
                        // The polygon is already tessellated as triangles
                        if (doSubDivise || prj->intersectViewportDiscontinuity(poly->getBoundingCap()))
                                // flag for color-modulated textured mode (e.g. for Milky Way/extincted)
                                drawSphericalTriangles(poly->getFillVertexArray(observerVelocity), drawMode>=SphericalPolygonDrawModeTextureFill, drawMode==SphericalPolygonDrawModeTextureFillColormodulated, clippingCap, doSubDivise, maxSqDistortion);
                        else
                                drawStelVertexArray(poly->getFillVertexArray(observerVelocity), false);

                        setCullFace(oldCullFace);
                        break;
                default:
                        Q_ASSERT(0);
        }
}


/*************************************************************************
 draw a simple circle, 2d viewport coordinates in pixel
*************************************************************************/
void StelPainter::drawCircle(float x, float y, float r)
{
        if (r <= 1.0f)
                return;
        const Vec2f center(x,y);
        const Vec2f v_center(0.5f*prj->viewportXywh[2],0.5f*prj->viewportXywh[3]);
        const float R = v_center.norm();
        const float d = (v_center-center).norm();
        if (d > r+R || d < r-R)
                return;
        const int segments = 180;
        const float phi = 2.0f*M_PIf/segments;
        const float cp = std::cos(phi);
        const float sp = std::sin(phi);
        float dx = r;
        float dy = 0;
        static QVarLengthArray<Vec3f, 180> circleVertexArray(180);

        for (int i=0;i<segments;i++)
        {
                circleVertexArray[i].set(x+dx,y+dy,0);
                r = dx*cp-dy*sp;
                dy = dx*sp+dy*cp;
                dx = r;
        }
        enableClientStates(true);
        setVertexPointer(3, GL_FLOAT, circleVertexArray.data());
        drawFromArray(LineLoop, 180, 0, false);
        enableClientStates(false);
}

void StelPainter::drawSprite2dMode(float x, float y, float radius)
{
        static float vertexData[] = {-10.,-10.,10.,-10., 10.,10., -10.,10.};
        static const float texCoordData[] = {0.,0., 1.,0., 0.,1., 1.,1.};
        
        // Takes into account device pixel density and global scale ratio, as we are drawing 2D stuff.
        radius *= static_cast<float>(prj->getDevicePixelsPerPixel())*StelApp::getInstance().getGlobalScalingRatio();
        
        vertexData[0]=x-radius; vertexData[1]=y-radius;
        vertexData[2]=x+radius; vertexData[3]=y-radius;
        vertexData[4]=x-radius; vertexData[5]=y+radius;
        vertexData[6]=x+radius; vertexData[7]=y+radius;
        enableClientStates(true, true);
        setVertexPointer(2, GL_FLOAT, vertexData);
        setTexCoordPointer(2, GL_FLOAT, texCoordData);
        drawFromArray(TriangleStrip, 4, 0, false);
        enableClientStates(false);
}

void StelPainter::drawSprite2dModeNoDeviceScale(float x, float y, float radius)
{
        drawSprite2dMode(x, y, radius/(static_cast<float>(prj->getDevicePixelsPerPixel())*StelApp::getInstance().getGlobalScalingRatio()));
}

void StelPainter::drawSprite2dMode(const Vec3d& v, float radius)
{
        Vec3d win;
        if (prj->project(v, win))
                drawSprite2dMode(static_cast<float>(win[0]), static_cast<float>(win[1]), radius);
}

void StelPainter::drawSprite2dMode(float x, float y, float radius, float rotation)
{
        static float vertexData[8];
        static const float texCoordData[] = {0.f,0.f, 1.f,0.f, 0.f,1.f, 1.f,1.f};

        // compute the vertex coordinates applying the translation and the rotation
        static const float vertexBase[] = {-1., -1., 1., -1., -1., 1., 1., 1.};
        const float cosr = std::cos(rotation * M_PI_180f);
        const float sinr = std::sin(rotation * M_PI_180f);
        
        // Takes into account device pixel density and global scale ratio, as we are drawing 2D stuff.
        radius *= static_cast<float>(prj->getDevicePixelsPerPixel())*StelApp::getInstance().getGlobalScalingRatio();
        
        for (int i = 0; i < 8; i+=2)
        {
                vertexData[i] = x + radius * vertexBase[i] * cosr - radius * vertexBase[i+1] * sinr;
                vertexData[i+1] = y + radius * vertexBase[i] * sinr + radius * vertexBase[i+1] * cosr;
        }

        enableClientStates(true, true);
        setVertexPointer(2, GL_FLOAT, vertexData);
        setTexCoordPointer(2, GL_FLOAT, texCoordData);
        drawFromArray(TriangleStrip, 4, 0, false);
        enableClientStates(false);
}

void StelPainter::drawRect2d(float x, float y, float width, float height, bool textured)
{
        static float vertexData[] = {-10.,-10.,10.,-10., 10.,10., -10.,10.};
        static const float texCoordData[] = {0.,0., 1.,0., 0.,1., 1.,1.};
        vertexData[0]=x; vertexData[1]=y;
        vertexData[2]=x+width; vertexData[3]=y;
        vertexData[4]=x; vertexData[5]=y+height;
        vertexData[6]=x+width; vertexData[7]=y+height;
        if (textured)
        {
                enableClientStates(true, true);
                setVertexPointer(2, GL_FLOAT, vertexData);
                setTexCoordPointer(2, GL_FLOAT, texCoordData);
        }
        else
        {
                enableClientStates(true);
                setVertexPointer(2, GL_FLOAT, vertexData);
        }
        drawFromArray(TriangleStrip, 4, 0, false);
        enableClientStates(false);
}

/*************************************************************************
 Draw a GL_POINT at the given position
*************************************************************************/
void StelPainter::drawPoint2d(float x, float y)
{
        static float vertexData[] = {0.,0.};
        vertexData[0]=x;
        vertexData[1]=y;

        enableClientStates(true);
        setVertexPointer(2, GL_FLOAT, vertexData);
        drawFromArray(Points, 1, 0, false);
        enableClientStates(false);
}


/*************************************************************************
 Draw a line between the 2 points.
*************************************************************************/
void StelPainter::drawLine2d(const float x1, const float y1, const float x2, const float y2)
{
        static float vertexData[] = {0.,0.,0.,0.};
        vertexData[0]=x1;
        vertexData[1]=y1;
        vertexData[2]=x2;
        vertexData[3]=y2;

        enableClientStates(true);
        setVertexPointer(2, GL_FLOAT, vertexData);
        drawFromArray(Lines, 2, 0, false);
        enableClientStates(false);
}

///////////////////////////////////////////////////////////////////////////
// Drawing methods for general (non-linear) mode.
// This used to draw a full sphere. Since 0.13 it's possible to have a spherical zone only.
void StelPainter::sSphere(const double radius, const double oneMinusOblateness,
                          const unsigned int slices, const unsigned int stacks,
                          const bool orientInside, const bool flipTexture, const float topAngle, const float bottomAngle)
{
        double x, y, z;
        GLfloat s=0.f, t=0.f;
        GLfloat nsign;

        if (orientInside)
        {
                nsign = -1.f;
                t=0.f; // from inside texture is reversed
        }
        else
        {
                nsign = 1.f;
                t=1.f;
        }

        const float* cos_sin_rho = Q_NULLPTR;
        Q_ASSERT(topAngle<bottomAngle); // don't forget: These are opening angles counted from top.
        if ((bottomAngle>3.1415f) && (topAngle<0.0001f)) // safety margin.
                cos_sin_rho = StelUtils::ComputeCosSinRho(stacks);
        else
        {
                const float drho = (bottomAngle-topAngle) / static_cast<float>(stacks); // deltaRho:  originally just 180degrees/stacks, now the range clamped.
                cos_sin_rho = StelUtils::ComputeCosSinRhoZone(drho, stacks, M_PIf-bottomAngle);
        }
        // Allow parameters so that pole regions may remain free.
        const float* cos_sin_rho_p;

        const float* cos_sin_theta = StelUtils::ComputeCosSinTheta(slices);
        const float *cos_sin_theta_p;

        // texturing: s goes from 0.0/0.25/0.5/0.75/1.0 at +y/+x/-y/-x/+y axis
        // t goes from -1.0/+1.0 at z = -radius/+radius (linear along longitudes)
        // cannot use triangle fan on texturing (s coord. at top/bottom tip varies)
        // If the texture is flipped, we iterate the coordinates backward.
        const GLfloat ds = (flipTexture ? -1.f : 1.f) / static_cast<float>(slices);
        const GLfloat dt = nsign / static_cast<float>(stacks); // from inside texture is reversed

        // draw intermediate as quad strips
        static QVector<double> vertexArr;
        static QVector<float> texCoordArr;
        static QVector<float> colorArr;
        static QVector<unsigned short> indiceArr;

        texCoordArr.resize(0);
        vertexArr.resize(0);
        colorArr.resize(0);
        indiceArr.resize(0);

        // LGTM comments: the floats are always <=1. We still prefer float multiplication (with insignificant accuracy loss) for speed.
        uint i, j;
        for (i = 0,cos_sin_rho_p = cos_sin_rho; i < stacks; ++i,cos_sin_rho_p+=2)
        {
                s = flipTexture ? 1.f : 0.f;
                for (j = 0,cos_sin_theta_p = cos_sin_theta; j<=slices;++j,cos_sin_theta_p+=2)
                {
                        x = static_cast<double>(-cos_sin_theta_p[1] * cos_sin_rho_p[1]);
                        y = static_cast<double>(cos_sin_theta_p[0] * cos_sin_rho_p[1]);
                        z = static_cast<double>(nsign * cos_sin_rho_p[0]);
                        texCoordArr << s << t;
                        vertexArr << x * radius << y * radius << z * oneMinusOblateness * radius;
                        x = static_cast<double>(-cos_sin_theta_p[1] * cos_sin_rho_p[3]);
                        y = static_cast<double>(cos_sin_theta_p[0] * cos_sin_rho_p[3]);
                        z = static_cast<double>(nsign * cos_sin_rho_p[2]);
                        texCoordArr << s << t - dt;
                        vertexArr << x * radius << y * radius << z * oneMinusOblateness * radius;
                        s += ds;
                }
                unsigned int offset = i*(slices+1)*2;
                for (j = 2;j<slices*2+2;j+=2)
                {
                        indiceArr << static_cast<unsigned short>(offset+j-2) << static_cast<unsigned short>(offset+j-1) << static_cast<unsigned short>(offset+j);
                        indiceArr << static_cast<unsigned short>(offset+j) << static_cast<unsigned short>(offset+j-1) << static_cast<unsigned short>(offset+j+1);
                }
                t -= dt;
        }

        // Draw the array now
        setArrays(reinterpret_cast<const Vec3d*>(vertexArr.constData()), reinterpret_cast<const Vec2f*>(texCoordArr.constData()));
        drawFromArray(Triangles, indiceArr.size(), 0, true, indiceArr.constData());
}

StelVertexArray StelPainter::computeSphereNoLight(double radius, double oneMinusOblateness, unsigned int slices, unsigned int stacks,
                          int orientInside, bool flipTexture, float topAngle, float bottomAngle)
{
        StelVertexArray result(StelVertexArray::Triangles);
        double x, y, z;
        GLfloat s=0.f, t=0.f;
        GLuint i, j;
        GLfloat nsign;
        if (orientInside)
        {
                nsign = -1.f;
                t=0.f; // from inside texture is reversed
        }
        else
        {
                nsign = 1.f;
                t=1.f;
        }

        const float* cos_sin_rho = Q_NULLPTR; //StelUtils::ComputeCosSinRho(stacks);
        Q_ASSERT(topAngle<bottomAngle); // don't forget: These are opening angles counted from top.
        if ((bottomAngle>3.1415f) && (topAngle<0.0001f)) // safety margin.
                cos_sin_rho = StelUtils::ComputeCosSinRho(stacks);
        else
        {
                const float drho = (bottomAngle-topAngle) / static_cast<float>(stacks); // deltaRho:  originally just 180degrees/stacks, now the range clamped.
                cos_sin_rho = StelUtils::ComputeCosSinRhoZone(drho, stacks, M_PIf-bottomAngle);
        }
        // Allow parameters so that pole regions may remain free.
        const float* cos_sin_rho_p;

        const float* cos_sin_theta = StelUtils::ComputeCosSinTheta(slices);
        const float *cos_sin_theta_p;

        // texturing: s goes from 0.0/0.25/0.5/0.75/1.0 at +y/+x/-y/-x/+y axis
        // t goes from -1.0/+1.0 at z = -radius/+radius (linear along longitudes)
        // cannot use triangle fan on texturing (s coord. at top/bottom tip varies)
        // If the texture is flipped, we iterate the coordinates backward.
        const GLfloat ds = (flipTexture ? -1.f : 1.f) / static_cast<float>(slices);
        const GLfloat dt = nsign / static_cast<float>(stacks); // from inside texture is reversed

        // draw intermediate as quad strips
        // LGTM comments: the floats are always <=1. We still prefer float multiplication (with insignificant accuracy loss) for speed.
        for (i = 0,cos_sin_rho_p = cos_sin_rho; i < stacks; ++i,cos_sin_rho_p+=2)
        {
                s = !flipTexture ? 0.f : 1.f;
                for (j = 0,cos_sin_theta_p = cos_sin_theta; j<=slices;++j,cos_sin_theta_p+=2)
                {
                        x = static_cast<double>(-cos_sin_theta_p[1] * cos_sin_rho_p[1]);
                        y = static_cast<double>(cos_sin_theta_p[0] * cos_sin_rho_p[1]);
                        z = static_cast<double>(nsign * cos_sin_rho_p[0]);
                        result.texCoords << Vec2f(s,t);
                        result.vertex << Vec3d(x*radius, y*radius, z*oneMinusOblateness*radius);
                        x = static_cast<double>(-cos_sin_theta_p[1] * cos_sin_rho_p[3]);
                        y = static_cast<double>(cos_sin_theta_p[0] * cos_sin_rho_p[3]);
                        z = static_cast<double>(nsign * cos_sin_rho_p[2]);
                        result.texCoords << Vec2f(s, t-dt);
                        result.vertex << Vec3d(x*radius, y*radius, z*oneMinusOblateness*radius);
                        s += ds;
                }
                unsigned int offset = i*(slices+1)*2;
                for (j = 2;j<slices*2+2;j+=2)
                {
                        result.indices << static_cast<unsigned short>(offset+j-2) << static_cast<unsigned short>(offset+j-1) << static_cast<unsigned short>(offset+j);
                        result.indices << static_cast<unsigned short>(offset+j) << static_cast<unsigned short>(offset+j-1) << static_cast<unsigned short>(offset+j+1);
                }
                t -= dt;
        }
        return result;
}

// Reimplementation of gluCylinder : glu is overridden for non standard projection
void StelPainter::sCylinder(double radius, double height, int slices, int orientInside)
{
        if (orientInside)
                glCullFace(GL_FRONT);

        static QVarLengthArray<Vec2f, 512> texCoordArray;
        static QVarLengthArray<Vec3d, 512> vertexArray;
        texCoordArray.clear();
        vertexArray.clear();
        float s = 0.f;
        double x, y;
        const float ds = 1.f / static_cast<float>(slices);
        const double da = 2. * M_PI / slices;
        for (int i = 0; i <= slices; ++i)
        {
                x = std::sin(da*i);
                y = std::cos(da*i);
                texCoordArray.append(Vec2f(s, 0.f));
                vertexArray.append(Vec3d(x*radius, y*radius, 0.));
                texCoordArray.append(Vec2f(s, 1.f));
                vertexArray.append(Vec3d(x*radius, y*radius, height));
                s += ds;
        }
        setArrays(vertexArray.constData(), texCoordArray.constData());
        drawFromArray(TriangleStrip, vertexArray.size());

        if (orientInside)
                glCullFace(GL_BACK);
}

void StelPainter::initGLShaders()
{
        qDebug() << "Initializing basic GL shaders... ";
        // Basic shader: just vertex filled with plain color
        QOpenGLShader vshader3(QOpenGLShader::Vertex);
        const auto vsrc3 =
                StelOpenGL::globalShaderPrefix(StelOpenGL::VERTEX_SHADER) +
                "ATTRIBUTE mediump vec3 vertex;\n"
                "uniform mediump mat4 projectionMatrix;\n"
                "void main(void)\n"
                "{\n"
                "    gl_Position = projectionMatrix*vec4(vertex, 1.);\n"
                "}\n";
        vshader3.compileSourceCode(vsrc3);
        if (!vshader3.log().isEmpty())
                qWarning().noquote() << "StelPainter: Warnings while compiling vshader3: " << vshader3.log();
        QOpenGLShader fshader3(QOpenGLShader::Fragment);
        const auto fsrc3 =
                StelOpenGL::globalShaderPrefix(StelOpenGL::FRAGMENT_SHADER) +
                "uniform mediump vec4 color;\n"
                "void main(void)\n"
                "{\n"
                "    FRAG_COLOR = color;\n"
                "}\n";
        fshader3.compileSourceCode(fsrc3);
        if (!fshader3.log().isEmpty())
                qWarning().noquote() << "StelPainter: Warnings while compiling fshader3: " << fshader3.log();
        basicShaderProgram = new QOpenGLShaderProgram(QOpenGLContext::currentContext());
        basicShaderProgram->addShader(&vshader3);
        basicShaderProgram->addShader(&fshader3);
        linkProg(basicShaderProgram, "basicShaderProgram");
        basicShaderVars.projectionMatrix = basicShaderProgram->uniformLocation("projectionMatrix");
        basicShaderVars.color = basicShaderProgram->uniformLocation("color");
        basicShaderVars.vertex = basicShaderProgram->attributeLocation("vertex");
        

        // Basic shader: vertex filled with interpolated color
        QOpenGLShader vshaderInterpolatedColor(QOpenGLShader::Vertex);
        const auto vshaderInterpolatedColorSrc =
                StelOpenGL::globalShaderPrefix(StelOpenGL::VERTEX_SHADER) +
                "ATTRIBUTE mediump vec3 vertex;\n"
                "ATTRIBUTE mediump vec4 color;\n"
                "uniform mediump mat4 projectionMatrix;\n"
                "VARYING mediump vec4 fragcolor;\n"
                "void main(void)\n"
                "{\n"
                "    gl_Position = projectionMatrix*vec4(vertex, 1.);\n"
                "    fragcolor = color;\n"
                "}\n";
        vshaderInterpolatedColor.compileSourceCode(vshaderInterpolatedColorSrc);
        if (!vshaderInterpolatedColor.log().isEmpty()) {
          qWarning().noquote() << "StelPainter: Warnings while compiling vshaderInterpolatedColor: " << vshaderInterpolatedColor.log();
        }
        QOpenGLShader fshaderInterpolatedColor(QOpenGLShader::Fragment);
        const auto fshaderInterpolatedColorSrc =
                StelOpenGL::globalShaderPrefix(StelOpenGL::FRAGMENT_SHADER) +
                "VARYING mediump vec4 fragcolor;\n"
                "void main(void)\n"
                "{\n"
                "    FRAG_COLOR = fragcolor;\n"
                "}\n";
        fshaderInterpolatedColor.compileSourceCode(fshaderInterpolatedColorSrc);
        if (!fshaderInterpolatedColor.log().isEmpty()) {
          qWarning().noquote() << "StelPainter: Warnings while compiling fshaderInterpolatedColor: " << fshaderInterpolatedColor.log();
        }
        colorShaderProgram = new QOpenGLShaderProgram(QOpenGLContext::currentContext());
        colorShaderProgram->addShader(&vshaderInterpolatedColor);
        colorShaderProgram->addShader(&fshaderInterpolatedColor);
        linkProg(colorShaderProgram, "colorShaderProgram");
        colorShaderVars.projectionMatrix = colorShaderProgram->uniformLocation("projectionMatrix");
        colorShaderVars.color = colorShaderProgram->attributeLocation("color");
        colorShaderVars.vertex = colorShaderProgram->attributeLocation("vertex");
        
        // Basic texture shader program
        QOpenGLShader vshader2(QOpenGLShader::Vertex);
        const auto vsrc2 =
                StelOpenGL::globalShaderPrefix(StelOpenGL::VERTEX_SHADER) +
                "ATTRIBUTE highp vec3 vertex;\n"
                "ATTRIBUTE mediump vec2 texCoord;\n"
                "uniform mediump mat4 projectionMatrix;\n"
                "VARYING mediump vec2 texc;\n"
                "void main(void)\n"
                "{\n"
                "    gl_Position = projectionMatrix * vec4(vertex, 1.);\n"
                "    texc = texCoord;\n"
                "}\n";
        vshader2.compileSourceCode(vsrc2);
        if (!vshader2.log().isEmpty())
                qWarning().noquote() << "StelPainter: Warnings while compiling vshader2: " << vshader2.log();

        QOpenGLShader fshader2(QOpenGLShader::Fragment);
        const auto fsrc2 =
                StelOpenGL::globalShaderPrefix(StelOpenGL::FRAGMENT_SHADER) +
                makeDitheringShader()+
                "VARYING mediump vec2 texc;\n"
                "uniform sampler2D tex;\n"
                "uniform mediump vec4 texColor;\n"
                "void main(void)\n"
                "{\n"
                "    FRAG_COLOR = dither(texture2D(tex, texc)*texColor);\n"
                "}\n";
        fshader2.compileSourceCode(fsrc2);
        if (!fshader2.log().isEmpty())
                qWarning().noquote() << "StelPainter: Warnings while compiling fshader2: " << fshader2.log();

        texturesShaderProgram = new QOpenGLShaderProgram(QOpenGLContext::currentContext());
        texturesShaderProgram->addShader(&vshader2);
        texturesShaderProgram->addShader(&fshader2);
        linkProg(texturesShaderProgram, "texturesShaderProgram");
        texturesShaderVars.projectionMatrix = texturesShaderProgram->uniformLocation("projectionMatrix");
        texturesShaderVars.texCoord = texturesShaderProgram->attributeLocation("texCoord");
        texturesShaderVars.vertex = texturesShaderProgram->attributeLocation("vertex");
        texturesShaderVars.texColor = texturesShaderProgram->uniformLocation("texColor");
        texturesShaderVars.texture = texturesShaderProgram->uniformLocation("tex");
        texturesShaderVars.ditherPattern = texturesShaderProgram->uniformLocation("ditherPattern");
        texturesShaderVars.rgbMaxValue = texturesShaderProgram->uniformLocation("rgbMaxValue");

        // Texture shader program + interpolated color per vertex
        QOpenGLShader vshader4(QOpenGLShader::Vertex);
        const auto vsrc4 =
                StelOpenGL::globalShaderPrefix(StelOpenGL::VERTEX_SHADER) +
                "ATTRIBUTE highp vec3 vertex;\n"
                "ATTRIBUTE mediump vec2 texCoord;\n"
                "ATTRIBUTE mediump vec4 color;\n"
                "uniform mediump mat4 projectionMatrix;\n"
                "VARYING mediump vec2 texc;\n"
                "VARYING mediump vec4 outColor;\n"
                "void main(void)\n"
                "{\n"
                "    gl_Position = projectionMatrix * vec4(vertex, 1.);\n"
                "    texc = texCoord;\n"
                "    outColor = color;\n"
                "}\n";
        vshader4.compileSourceCode(vsrc4);
        if (!vshader4.log().isEmpty())
                qWarning().noquote() << "StelPainter: Warnings while compiling vshader4: " << vshader4.log();

        QOpenGLShader fshader4(QOpenGLShader::Fragment);
        const auto fsrc4 =
                StelOpenGL::globalShaderPrefix(StelOpenGL::FRAGMENT_SHADER) +
                makeDitheringShader()+
                makeSaturationShader()+
                "VARYING mediump vec2 texc;\n"
                "VARYING mediump vec4 outColor;\n"
                "uniform sampler2D tex;\n"
                "uniform lowp float saturation;\n"
                "void main(void)\n"
                "{\n"
                "    FRAG_COLOR = dither(texture2D(tex, texc)*outColor);\n"
                "    if (saturation != 1.0)\n"
                "        FRAG_COLOR.rgb = saturate(FRAG_COLOR.rgb, saturation);\n"
                "}\n";
        fshader4.compileSourceCode(fsrc4);
        if (!fshader4.log().isEmpty())
                qWarning().noquote() << "StelPainter: Warnings while compiling fshader4: " << fshader4.log();

        texturesColorShaderProgram = new QOpenGLShaderProgram(QOpenGLContext::currentContext());
        texturesColorShaderProgram->addShader(&vshader4);
        texturesColorShaderProgram->addShader(&fshader4);
        linkProg(texturesColorShaderProgram, "texturesColorShaderProgram");
        texturesColorShaderVars.projectionMatrix = texturesColorShaderProgram->uniformLocation("projectionMatrix");
        texturesColorShaderVars.texCoord = texturesColorShaderProgram->attributeLocation("texCoord");
        texturesColorShaderVars.vertex = texturesColorShaderProgram->attributeLocation("vertex");
        texturesColorShaderVars.color = texturesColorShaderProgram->attributeLocation("color");
        texturesColorShaderVars.texture = texturesColorShaderProgram->uniformLocation("tex");
        texturesColorShaderVars.ditherPattern = texturesColorShaderProgram->uniformLocation("ditherPattern");
        texturesColorShaderVars.rgbMaxValue = texturesColorShaderProgram->uniformLocation("rgbMaxValue");
        texturesColorShaderVars.saturation = texturesColorShaderProgram->uniformLocation("saturation");

        if(StelMainView::getInstance().getGLInformation().isCoreProfile)
        {
                // In Core profile wide lines (width>1px) are not supported, so this shader is used to render them with triangles.

                // Common template for the geometry shader
                const QByteArray geomSrc = 1+R"(
#version 330

layout(lines) in;
layout(triangle_strip, max_vertices=4) out;
uniform vec2 viewportSize;
uniform float lineWidth;
#if @VARYING_COLOR@
in vec4 varyingColor[2];
out vec4 geomColor;
#endif

void main()
{
        vec4 clip0 = gl_in[0].gl_Position;
        vec4 clip1 = gl_in[1].gl_Position;

        vec3 ndc0 = clip0.xyz / clip0.w;
        vec3 ndc1 = clip1.xyz / clip1.w;

        vec2 lineDir2d = normalize((ndc1.xy - ndc0.xy) * viewportSize);
        vec2 perpendicularDir2d = vec2(-lineDir2d.y, lineDir2d.x);

        vec2 offset2d = (lineWidth / viewportSize) * perpendicularDir2d;

        gl_Position = vec4(clip0.xy + offset2d*clip0.w, clip0.zw);
#if @VARYING_COLOR@
        geomColor = varyingColor[0];
#endif
        EmitVertex();

        gl_Position = vec4(clip0.xy - offset2d*clip0.w, clip0.zw);
#if @VARYING_COLOR@
        geomColor = varyingColor[0];
#endif
        EmitVertex();

        gl_Position = vec4(clip1.xy + offset2d*clip1.w, clip1.zw);
#if @VARYING_COLOR@
        geomColor = varyingColor[1];
#endif
        EmitVertex();

        gl_Position = vec4(clip1.xy - offset2d*clip1.w, clip1.zw);
#if @VARYING_COLOR@
        geomColor = varyingColor[1];
#endif
        EmitVertex();

        EndPrimitive();
}
)";

                // First a basic shader using constant line color
                QOpenGLShader wideLineVertShader(QOpenGLShader::Vertex);
                wideLineVertShader.compileSourceCode(1+R"(
#version 330
in vec3 vertex;
uniform mat4 projectionMatrix;
void main()
{
    gl_Position = projectionMatrix*vec4(vertex, 1.);
}
)");
                if (!wideLineVertShader.log().isEmpty())
                        qWarning().noquote() << "StelPainter: Warnings while compiling wide line vertex shader: " << wideLineVertShader.log();

                QOpenGLShader wideLineGeomShader(QOpenGLShader::Geometry);
                wideLineGeomShader.compileSourceCode(QByteArray(geomSrc).replace("@VARYING_COLOR@","0"));
                if (!wideLineGeomShader.log().isEmpty())
                        qWarning().noquote() << "StelPainter: Warnings while compiling wide line geometry shader: " << wideLineGeomShader.log();

                QOpenGLShader wideLineFragShader(QOpenGLShader::Fragment);
                wideLineFragShader.compileSourceCode(1+R"(
#version 330
uniform vec4 color;
out vec4 outputColor;
void main()
{
    outputColor = color;
}
)");
                if (!wideLineFragShader.log().isEmpty())
                        qWarning().noquote() << "StelPainter: Warnings while compiling wide line fragment shader: " << wideLineFragShader.log();
                wideLineShaderProgram = new QOpenGLShaderProgram(QOpenGLContext::currentContext());
                wideLineShaderProgram->addShader(&wideLineVertShader);
                wideLineShaderProgram->addShader(&wideLineGeomShader);
                wideLineShaderProgram->addShader(&wideLineFragShader);
                linkProg(wideLineShaderProgram, "wideLineShaderProgram");
                wideLineShaderVars.projectionMatrix = wideLineShaderProgram->uniformLocation("projectionMatrix");
                wideLineShaderVars.viewportSize     = wideLineShaderProgram->uniformLocation("viewportSize");
                wideLineShaderVars.lineWidth        = wideLineShaderProgram->uniformLocation("lineWidth");
                wideLineShaderVars.color            = wideLineShaderProgram->uniformLocation("color");
                wideLineShaderVars.vertex = wideLineShaderProgram->attributeLocation("vertex");

                // Now a version of the shader that supports color interpolated along the line
                QOpenGLShader colorfulWideLineVertShader(QOpenGLShader::Vertex);
                colorfulWideLineVertShader.compileSourceCode(1+R"(
#version 330
in vec3 vertex;
in vec4 color;
out vec4 varyingColor;
uniform mat4 projectionMatrix;
void main()
{
    gl_Position = projectionMatrix*vec4(vertex, 1.);
        varyingColor = color;
}
)");
                if (!colorfulWideLineVertShader.log().isEmpty())
                        qWarning().noquote() << "StelPainter: Warnings while compiling colorful wide line vertex shader: " << colorfulWideLineVertShader.log();

                QOpenGLShader colorfulWideLineGeomShader(QOpenGLShader::Geometry);
                colorfulWideLineGeomShader.compileSourceCode(QByteArray(geomSrc).replace("@VARYING_COLOR@","1"));
                if (!colorfulWideLineGeomShader.log().isEmpty())
                        qWarning().noquote() << "StelPainter: Warnings while compiling colorful wide line geometry shader: " << colorfulWideLineGeomShader.log();

                QOpenGLShader colorfulWideLineFragShader(QOpenGLShader::Fragment);
                colorfulWideLineFragShader.compileSourceCode(1+R"(
#version 330
in vec4 geomColor;
out vec4 outputColor;
void main()
{
    outputColor = geomColor;
}
)");
                if (!colorfulWideLineFragShader.log().isEmpty())
                        qWarning().noquote() << "StelPainter: Warnings while compiling colorful wide line fragment shader: " << colorfulWideLineFragShader.log();
                colorfulWideLineShaderProgram = new QOpenGLShaderProgram(QOpenGLContext::currentContext());
                colorfulWideLineShaderProgram->addShader(&colorfulWideLineVertShader);
                colorfulWideLineShaderProgram->addShader(&colorfulWideLineGeomShader);
                colorfulWideLineShaderProgram->addShader(&colorfulWideLineFragShader);
                linkProg(colorfulWideLineShaderProgram, "colorfulWideLineShaderProgram");
                colorfulWideLineShaderVars.projectionMatrix = colorfulWideLineShaderProgram->uniformLocation("projectionMatrix");
                colorfulWideLineShaderVars.viewportSize     = colorfulWideLineShaderProgram->uniformLocation("viewportSize");
                colorfulWideLineShaderVars.lineWidth        = colorfulWideLineShaderProgram->uniformLocation("lineWidth");
                colorfulWideLineShaderVars.color  = colorfulWideLineShaderProgram->attributeLocation("color");
                colorfulWideLineShaderVars.vertex = colorfulWideLineShaderProgram->attributeLocation("vertex");
        }

        multisamplingEnabled = StelApp::getInstance().getSettings()->value("video/multisampling", 0).toUInt() != 0;
}


void StelPainter::deinitGLShaders()
{
        delete basicShaderProgram;
        basicShaderProgram = Q_NULLPTR;
        delete colorShaderProgram;
        colorShaderProgram = Q_NULLPTR;
        delete texturesShaderProgram;
        texturesShaderProgram = Q_NULLPTR;
        delete texturesColorShaderProgram;
        texturesColorShaderProgram = Q_NULLPTR;
        delete wideLineShaderProgram;
        wideLineShaderProgram = Q_NULLPTR;
        delete colorfulWideLineShaderProgram;
        colorfulWideLineShaderProgram = Q_NULLPTR;
        texCache.clear();
}


void StelPainter::setArrays(const Vec3d* vertices, const Vec2f* texCoords, const Vec3f* colorArray, const Vec3f* normalArray)
{
        enableClientStates(vertices, texCoords, colorArray, normalArray);
        setVertexPointer(3, GL_DOUBLE, vertices);
        setTexCoordPointer(2, GL_FLOAT, texCoords);
        setColorPointer(3, GL_FLOAT, colorArray);
        setNormalPointer(GL_FLOAT, normalArray);
}

void StelPainter::setArrays(const Vec3f* vertices, const Vec2f* texCoords, const Vec3f* colorArray, const Vec3f* normalArray)
{
        enableClientStates(vertices, texCoords, colorArray, normalArray);
        setVertexPointer(3, GL_FLOAT, vertices);
        setTexCoordPointer(2, GL_FLOAT, texCoords);
        setColorPointer(3, GL_FLOAT, colorArray);
        setNormalPointer(GL_FLOAT, normalArray);
}

void StelPainter::enableClientStates(bool vertex, bool texture, bool color, bool normal)
{
        vertexArray.enabled = vertex;
        texCoordArray.enabled = texture;
        colorArray.enabled = color;
        normalArray.enabled = normal;
}

void StelPainter::drawFixedColorWideLinesAsQuads(const ArrayDesc& vertexArray, int count, int offset,
                                                                                                         const Mat4f& projMat, const DrawingMode mode)
{
        if(count < 2) return;

        GLint viewport[4] = {};
        glGetIntegerv(GL_VIEWPORT, viewport);
        const auto viewportSize = Vec2f(viewport[2], viewport[3]);

        std::vector<Vec4f> newVertices;
        if(mode == LineStrip)
                newVertices.reserve((count-1)*6);
        else
                newVertices.reserve(count*6);
        newVertices.resize((count-1)*6);
        assert(vertexArray.type == GL_FLOAT);
        const auto lineVertData = static_cast<const float*>(vertexArray.pointer) + vertexArray.size*offset;
        const int step = mode==Lines ? 2 : 1;
        for(int n = 0; n < count-1; n += step)
        {
                Vec4f in0;
                Vec4f in1;
                switch(vertexArray.size)
                {
                case 4:
                        in0 = Vec4f(lineVertData+4*(n+0));
                        in1 = Vec4f(lineVertData+4*(n+1));
                        break;
                case 3:
                        in0 = Vec4f(lineVertData[3*(n+0)], lineVertData[3*(n+0)+1], lineVertData[3*(n+0)+2], 1);
                        in1 = Vec4f(lineVertData[3*(n+1)], lineVertData[3*(n+1)+1], lineVertData[3*(n+1)+2], 1);
                        break;
                case 2:
                        in0 = Vec4f(lineVertData[2*(n+0)], lineVertData[2*(n+0)+1], 0, 1);
                        in1 = Vec4f(lineVertData[2*(n+1)], lineVertData[2*(n+1)+1], 0, 1);
                        break;
                case 1:
                        in0 = Vec4f(lineVertData[n+0], 0,0,1);
                        in1 = Vec4f(lineVertData[n+1], 0,0,1);
                        break;
                default:
                        in0 = Vec4f(0.f);
                        in1 = Vec4f(0.f);
                        assert(!"Bad number of elements in vertex array");
                }

                const Vec4f clip0 = projMat * Vec4f(in0);
                const Vec4f clip1 = projMat * Vec4f(in1);

                const Vec3f ndc0 = Vec3f(clip0.v) / clip0[3];
                const Vec3f ndc1 = Vec3f(clip1.v) / clip1[3];

                const Vec2f lineDir2d = normalize((Vec2f(ndc1.v) - Vec2f(ndc0.v)) * viewportSize);
                const Vec2f perpendicularDir2d = Vec2f(-lineDir2d[1], lineDir2d[0]);

                const Vec2f offset2d = (Vec2f(glState.lineWidth) / viewportSize) * perpendicularDir2d;

                // 2D screen coordinates of the new pairs (a,b) of vertices for each input vertex (0,1)
                const Vec2f v0a_xy = Vec2f(clip0.v) + offset2d*clip0[3];
                const Vec2f v0b_xy = Vec2f(clip0.v) - offset2d*clip0[3];
                const Vec2f v1a_xy = Vec2f(clip1.v) + offset2d*clip1[3];
                const Vec2f v1b_xy = Vec2f(clip1.v) - offset2d*clip1[3];

                // Final 4D coordinates of the new vertices
                const auto v0a = Vec4f(v0a_xy[0], v0a_xy[1], clip0[2], clip0[3]);
                const auto v0b = Vec4f(v0b_xy[0], v0b_xy[1], clip0[2], clip0[3]);
                const auto v1a = Vec4f(v1a_xy[0], v1a_xy[1], clip1[2], clip1[3]);
                const auto v1b = Vec4f(v1b_xy[0], v1b_xy[1], clip1[2], clip1[3]);

                newVertices[6*n+0] = v0a;
                newVertices[6*n+1] = v0b;
                newVertices[6*n+2] = v1a;

                newVertices[6*n+3] = v1a;
                newVertices[6*n+4] = v0b;
                newVertices[6*n+5] = v1b;
        }
        if(mode == LineLoop)
        {
                // Connect the ends
                const auto lastN = newVertices.size()-1;
                assert(lastN >= 2);
                newVertices.push_back(newVertices[lastN-2]);
                newVertices.push_back(newVertices[lastN]);
                newVertices.push_back(newVertices[0]);

                newVertices.push_back(newVertices[0]);
                newVertices.push_back(newVertices[lastN]);
                newVertices.push_back(newVertices[1]);
        }
        vao->bind();
        verticesVBO->bind();

        verticesVBO->allocate(newVertices.data(), newVertices.size() * sizeof newVertices[0]);

        const auto& pr = basicShaderProgram;
        pr->bind();
        pr->setAttributeBuffer(basicShaderVars.vertex, vertexArray.type, 0, 4);
        pr->enableAttributeArray(basicShaderVars.vertex);
        pr->setUniformValue(basicShaderVars.projectionMatrix, QMatrix4x4{});
        pr->setUniformValue(basicShaderVars.color, currentColor.toQVector());

#ifdef GL_MULTISAMPLE
        const bool multisampleWasOn = multisamplingEnabled && glIsEnabled(GL_MULTISAMPLE);
        if(multisamplingEnabled && glState.lineSmooth)
                glEnable(GL_MULTISAMPLE);
#endif

        // TODO: convert this to a triangle strip, but mind the overlaps and gaps of non-parallel lines' corners
        glDrawArrays(GL_TRIANGLES, 0, newVertices.size());

        verticesVBO->release();
        vao->release();

        if (pr) pr->release();

#ifdef GL_MULTISAMPLE
        if(multisamplingEnabled && !multisampleWasOn && glState.lineSmooth)
                glDisable(GL_MULTISAMPLE);
#endif
}

void StelPainter::drawFromArray(DrawingMode mode, int count, int offset, bool doProj, const unsigned short* indices)
{
        if(!count) return;

        ArrayDesc projectedVertexArray = vertexArray;
        if (doProj)
        {
                // Project the vertex array using current projection
                if (indices)
                        projectedVertexArray = projectArray(vertexArray, 0, count, indices + offset);
                else
                        projectedVertexArray = projectArray(vertexArray, offset, count, Q_NULLPTR);
        }

        QOpenGLShaderProgram* pr=Q_NULLPTR;

        const Mat4f& m = getProjector()->getProjectionMatrix();
        const QMatrix4x4 qMat(m[0], m[4], m[8], m[12], m[1], m[5], m[9], m[13], m[2], m[6], m[10], m[14], m[3], m[7], m[11], m[15]);

        const bool lineMode = mode==LineStrip || mode==LineLoop || mode==Lines;
        const bool isCoreProfile = StelMainView::getInstance().getGLInformation().isCoreProfile;
        const bool isGLES = StelMainView::getInstance().getGLInformation().isGLES;
        const bool wideLineMode = lineMode && glState.lineWidth>1;
        if(wideLineMode && (isCoreProfile || isGLES) && projectedVertexArray.type == GL_FLOAT)
        {
                const bool fixedColor = !texCoordArray.enabled && !colorArray.enabled && !normalArray.enabled;
                if(fixedColor && !indices)
                {
                        // Optimized version that doesn't use geometry shader, which appears to be slow on some GPUs.
                        // Ideally, we'd like to get rid of the geometry shader completely,
                        // but this will result in more code for small performance gain.
                        drawFixedColorWideLinesAsQuads(projectedVertexArray, count, offset, m, mode);
                        return;
                }
        }
        const bool coreProfileWideLineMode = wideLineMode && isCoreProfile;

        vao->bind();
        verticesVBO->bind();
        GLsizeiptr numberOfVerticesToCopy = count + offset;
        if(indices)
        {
                indicesVBO->bind();
                indicesVBO->allocate(indices+offset, count * sizeof indices[0]);
                numberOfVerticesToCopy = 1 + *std::max_element(indices + offset, indices + offset + count);
        }

#ifdef GL_MULTISAMPLE
        const bool multisampleWasOn = multisamplingEnabled && glIsEnabled(GL_MULTISAMPLE);
#endif

        const auto core = StelApp::getInstance().getCore();
        const auto rgbMaxValue=calcRGBMaxValue(core->getDitheringMode());
        if (!texCoordArray.enabled && !colorArray.enabled && !normalArray.enabled)
        {
                pr = coreProfileWideLineMode ? wideLineShaderProgram : basicShaderProgram;
                pr->bind();

                verticesVBO->allocate(projectedVertexArray.pointer, projectedVertexArray.vertexSizeInBytes()*numberOfVerticesToCopy);

#ifdef GL_MULTISAMPLE
                if(multisamplingEnabled && glState.lineSmooth)
                        glEnable(GL_MULTISAMPLE);
#endif
                if(coreProfileWideLineMode)
                {
                        pr->setAttributeBuffer(wideLineShaderVars.vertex, projectedVertexArray.type, 0, projectedVertexArray.size);
                        pr->enableAttributeArray(wideLineShaderVars.vertex);
                        pr->setUniformValue(wideLineShaderVars.projectionMatrix, qMat);
                        pr->setUniformValue(wideLineShaderVars.color, currentColor.toQVector());
                        pr->setUniformValue(wideLineShaderVars.lineWidth, glState.lineWidth);
                        GLint viewport[4] = {};
                        glGetIntegerv(GL_VIEWPORT, viewport);
                        pr->setUniformValue(wideLineShaderVars.viewportSize, QVector2D(viewport[2], viewport[3]));
                }
                else
                {
                        pr->setAttributeBuffer(basicShaderVars.vertex, projectedVertexArray.type, 0, projectedVertexArray.size);
                        pr->enableAttributeArray(basicShaderVars.vertex);
                        pr->setUniformValue(basicShaderVars.projectionMatrix, qMat);
                        pr->setUniformValue(basicShaderVars.color, currentColor.toQVector());
                }
        }
        else if (texCoordArray.enabled && !colorArray.enabled && !normalArray.enabled && !wideLineMode)
        {
                pr = texturesShaderProgram;
                pr->bind();

                const auto bufferSize = projectedVertexArray.vertexSizeInBytes()*numberOfVerticesToCopy +
                                                                texCoordArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->allocate(bufferSize);
                const auto vertexDataSize = projectedVertexArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->write(0, projectedVertexArray.pointer, vertexDataSize);
                const auto texCoordDataOffset = vertexDataSize;
                const auto texCoordDataSize = texCoordArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->write(texCoordDataOffset, texCoordArray.pointer, texCoordDataSize);

                pr->setAttributeBuffer(texturesShaderVars.vertex, projectedVertexArray.type, 0, projectedVertexArray.size);
                pr->enableAttributeArray(texturesShaderVars.vertex);
                pr->setUniformValue(texturesShaderVars.projectionMatrix, qMat);
                pr->setUniformValue(texturesShaderVars.texColor, currentColor.toQVector());
                pr->setAttributeBuffer(texturesShaderVars.texCoord, texCoordArray.type, texCoordDataOffset, texCoordArray.size);
                pr->enableAttributeArray(texturesShaderVars.texCoord);
                //pr->setUniformValue(texturesShaderVars.texture, 0);    // use texture unit 0
                const int ditherTexSampler = 1;
                if(!ditherPatternTex)
                        ditherPatternTex = StelApp::getInstance().getTextureManager().getDitheringTexture(ditherTexSampler);
                else
                        ditherPatternTex->bind(ditherTexSampler);
                pr->setUniformValue(texturesShaderVars.ditherPattern, ditherTexSampler);
                pr->setUniformValue(texturesShaderVars.rgbMaxValue, rgbMaxValue[0], rgbMaxValue[1], rgbMaxValue[2]);
        }
        else if (texCoordArray.enabled && colorArray.enabled && !normalArray.enabled && !wideLineMode)
        {
                pr = texturesColorShaderProgram;
                pr->bind();

                const auto bufferSize = projectedVertexArray.vertexSizeInBytes()*numberOfVerticesToCopy +
                                                                texCoordArray.vertexSizeInBytes()*numberOfVerticesToCopy +
                                                                colorArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->allocate(bufferSize);
                const auto vertexDataSize = projectedVertexArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->write(0, projectedVertexArray.pointer, vertexDataSize);
                const auto texCoordDataOffset = vertexDataSize;
                const auto texCoordDataSize = texCoordArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->write(texCoordDataOffset, texCoordArray.pointer, texCoordDataSize);
                const auto colorDataOffset = vertexDataSize + texCoordDataSize;
                const auto colorDataSize = colorArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->write(colorDataOffset, colorArray.pointer, colorDataSize);

                pr->setAttributeBuffer(texturesColorShaderVars.vertex, projectedVertexArray.type, 0, projectedVertexArray.size);
                pr->enableAttributeArray(texturesColorShaderVars.vertex);
                pr->setUniformValue(texturesColorShaderVars.projectionMatrix, qMat);
                pr->setAttributeBuffer(texturesColorShaderVars.texCoord, texCoordArray.type, texCoordDataOffset, texCoordArray.size);
                pr->enableAttributeArray(texturesColorShaderVars.texCoord);
                pr->setAttributeBuffer(texturesColorShaderVars.color, colorArray.type, colorDataOffset, colorArray.size);
                pr->enableAttributeArray(texturesColorShaderVars.color);
                //pr->setUniformValue(texturesShaderVars.texture, 0);    // use texture unit 0
                const int ditherTexSampler = 1;
                if(!ditherPatternTex)
                        ditherPatternTex = StelApp::getInstance().getTextureManager().getDitheringTexture(ditherTexSampler);
                else
                        ditherPatternTex->bind(ditherTexSampler);
                pr->setUniformValue(texturesColorShaderVars.ditherPattern, ditherTexSampler);
                pr->setUniformValue(texturesColorShaderVars.rgbMaxValue, rgbMaxValue[0], rgbMaxValue[1], rgbMaxValue[2]);
                pr->setUniformValue(texturesColorShaderVars.saturation, saturation);
        }
        else if (!texCoordArray.enabled && colorArray.enabled && !normalArray.enabled)
        {
                pr = coreProfileWideLineMode ? colorfulWideLineShaderProgram : colorShaderProgram;
                pr->bind();

                const auto bufferSize = projectedVertexArray.vertexSizeInBytes()*numberOfVerticesToCopy +
                                                                colorArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->allocate(bufferSize);
                const auto vertexDataSize = projectedVertexArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->write(0, projectedVertexArray.pointer, vertexDataSize);
                const auto colorDataOffset = vertexDataSize;
                const auto colorDataSize = colorArray.vertexSizeInBytes()*numberOfVerticesToCopy;
                verticesVBO->write(colorDataOffset, colorArray.pointer, colorDataSize);

                if(coreProfileWideLineMode)
                {
                        pr->setAttributeBuffer(colorfulWideLineShaderVars.vertex, projectedVertexArray.type, 0, projectedVertexArray.size);
                        pr->enableAttributeArray(colorfulWideLineShaderVars.vertex);
                        pr->setAttributeBuffer(colorfulWideLineShaderVars.color, colorArray.type, colorDataOffset, colorArray.size);
                        pr->enableAttributeArray(colorfulWideLineShaderVars.color);
                        pr->setUniformValue(colorfulWideLineShaderVars.projectionMatrix, qMat);
                        pr->setUniformValue(colorfulWideLineShaderVars.lineWidth, glState.lineWidth);
                        GLint viewport[4] = {};
                        glGetIntegerv(GL_VIEWPORT, viewport);
                        pr->setUniformValue(colorfulWideLineShaderVars.viewportSize, QVector2D(viewport[2], viewport[3]));
                }
                else
                {
                        pr->setAttributeBuffer(colorShaderVars.vertex, projectedVertexArray.type, 0, projectedVertexArray.size);
                        pr->enableAttributeArray(colorShaderVars.vertex);
                        pr->setUniformValue(colorShaderVars.projectionMatrix, qMat);
                        pr->setAttributeBuffer(colorShaderVars.color, colorArray.type, colorDataOffset, colorArray.size);
                        pr->enableAttributeArray(colorShaderVars.color);
                }
#ifdef GL_MULTISAMPLE
                if(multisamplingEnabled && glState.lineSmooth)
                        glEnable(GL_MULTISAMPLE);
#endif
        }
        else
        {
                qDebug() << "Unhandled parameters." << texCoordArray.enabled << colorArray.enabled << normalArray.enabled << wideLineMode;
                Q_ASSERT(0);
                return;
        }
        
        if (indices)
                glDrawElements(mode, count, GL_UNSIGNED_SHORT, 0);
        else
                glDrawArrays(mode, offset, count);

        verticesVBO->release();
        indicesVBO->release();
        vao->release();

        if (pr)
                pr->release();

#ifdef GL_MULTISAMPLE
        if(multisamplingEnabled && !multisampleWasOn && wideLineMode && glState.lineSmooth)
                glDisable(GL_MULTISAMPLE);
#endif
}

size_t StelPainter::ArrayDesc::vertexSizeInBytes() const
{
        size_t elemSize = 1;
        switch(type)
        {
        case GL_SHORT:
                elemSize = sizeof(GLshort);
                break;
        case GL_INT:
                elemSize = sizeof(GLint);
                break;
        case GL_FLOAT:
                elemSize = sizeof(GLfloat);
                break;
#if GL_DOUBLE != GL_FLOAT // see StelOpenGL.hpp
        case GL_DOUBLE:
                elemSize = sizeof(GLdouble);
                break;
#endif
        default:
                Q_ASSERT_X(false, Q_FUNC_INFO, "Unexpected element type");
                break;
        }
        return elemSize * size;
}

StelPainter::ArrayDesc StelPainter::projectArray(const StelPainter::ArrayDesc& array, int offset, int count, const unsigned short* indices)
{
        // XXX: we should use a more generic way to test whether or not to do the projection.
        if (dynamic_cast<StelProjector2d*>(prj.data()))
        {
                return array;
        }

        Q_ASSERT(array.size == 3);
        Q_ASSERT(array.type == GL_DOUBLE);
        const Vec3d* vecArray = reinterpret_cast<const Vec3d *>(const_cast<void*>(array.pointer));

        // We have two different cases :
        // 1) We are not using an indice array.  In that case the size of the array is known
        // 2) We are using an indice array.  In that case we have to find the max value by iterating through the indices.
        if (!indices)
        {
                polygonVertexArray.resize(offset + count);
                prj->project(count, vecArray + offset, polygonVertexArray.data() + offset);
        } else
        {
                // we need to find the max value of the indices !
                unsigned short max = 0;
                for (int i = offset; i < offset + count; ++i)
                {
                        max = std::max(max, indices[i]);
                }
                polygonVertexArray.resize(max+1);
                prj->project(max + 1, vecArray + offset, polygonVertexArray.data() + offset);
        }

        ArrayDesc ret;
        ret.size = 3;
        ret.type = GL_FLOAT;
        ret.pointer = polygonVertexArray.constData();
        ret.enabled = array.enabled;
        return ret;
}


Stellarium / stellarium / 4853788370

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