#include <QApplication>
#include <QMainWindow>
#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <QDebug>
#include <QLoggingCategory>
#include <QTimer>
#include <gl/GL.h>
#include <gl/GLU.h>

class GLWidget : public QOpenGLWidget {

public:
  GLWidget(QWidget *parent = NULL) : QOpenGLWidget(parent)
  {
  }

protected:
  void GLWidget::initializeGL()
  {
    glDisable(GL_TEXTURE_2D);
    glDisable(GL_DEPTH_TEST);
    glDisable(GL_COLOR_MATERIAL);
    glEnable(GL_BLEND);
    glEnable(GL_POLYGON_SMOOTH);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glClearColor(0, 0, 0, 0);

    GLboolean gbStereoEnabled = GL_FALSE;
    glGetBooleanv(GL_STEREO, &gbStereoEnabled);

    qDebug() << "initializeGL: glGetBooleanv(GL_STEREO) returned" << ((gbStereoEnabled != GL_FALSE) ? "TRUE" : "FALSE");
  }

  void GLWidget::resizeGL(int w, int h)
  {
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0, w, 0, h); // set origin to bottom left corner
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    GLboolean gbStereoEnabled = GL_FALSE;
    glGetBooleanv(GL_STEREO, &gbStereoEnabled);

    qDebug() << "resizeGL: glGetBooleanv(GL_STEREO) returned" << ((gbStereoEnabled != GL_FALSE) ? "TRUE" : "FALSE");
  }

  void GLWidget::paintGL()
  {
    glClear(GL_COLOR_BUFFER_BIT);
    glColor3f(1, 0, 0);
    glBegin(GL_POLYGON);
    glVertex2f(0, 0);
    glVertex2f(100, 500);
    glVertex2f(500, 100);
    glEnd();

    GLboolean gbStereoEnabled = GL_FALSE;
    glGetBooleanv(GL_STEREO, &gbStereoEnabled);

    qDebug() << "paintGL: glGetBooleanv(GL_STEREO) returned" << ((gbStereoEnabled != GL_FALSE) ? "TRUE" : "FALSE");
  }
};


int main(int argc, char** argv)
{
  QApplication app(argc, argv);

  QSurfaceFormat stereoFormat = QSurfaceFormat::defaultFormat();

  stereoFormat.setStereo(true);

  qDebug() << QT_VERSION_STR << "QSurfaceFormat::stereo for default=" << stereoFormat.stereo();

  QSurfaceFormat::setDefaultFormat(stereoFormat);

  stereoFormat.setStereo(true);

  qDebug() << "QSurfaceFormat::stereo" << stereoFormat.stereo();

  GLWidget window;

  window.setFormat(stereoFormat);

  window.setWindowTitle(QT_VERSION_STR);

  window.show();

  GLboolean gbStereoEnabled = GL_FALSE;

  QApplication::processEvents();

  glGetBooleanv(GL_STEREO, &gbStereoEnabled);

  qDebug() << "main: glGetBooleanv(GL_STEREO) returned" << ((gbStereoEnabled != GL_FALSE) ? "TRUE" : "FALSE");

  return app.exec();

}