Launcher: quit if OpenGL 2.1 isn’t available

Avoid crashing if no OpenGL drivers are available, instead show a
warning message to alert the user.

Sentry-Id: FLIGHTGEAR-76

src/GUI/LauncherMainWindow.cxx

@@ -9,12 +9,13 @@
 #include <QMenu>
 #include <QMenuBar>
 
-#include <QQuickItem>
-#include <QQmlEngine>
+#include <QOpenGLContext>
 #include <QQmlComponent>
 #include <QQmlContext>
+#include <QQmlEngine>
 #include <QQmlError>
 #include <QQmlFileSelector>
+#include <QQuickItem>
 
 // launcher headers
 #include "AddOnsController.hxx"
@@ -30,6 +31,8 @@
 #include "UpdateChecker.hxx"
 #include "GettingStartedTip.hxx"
 
+#include <Main/sentryIntegration.hxx>
+
 //////////////////////////////////////////////////////////////////////////////
 
 LauncherMainWindow::LauncherMainWindow(bool inSimMode) : QQuickView()
@@ -39,6 +42,13 @@ LauncherMainWindow::LauncherMainWindow(bool inSimMode) : QQuickView()
     m_controller = new LauncherController(this, this);
     m_controller->initQML();
 
+    // use a direct connection to be notified synchronously when the render thread
+    // starts OpenGL. We use this to log the OpenGL information from the
+    // context at that time, for tracing purposes.
+    connect(this, &QQuickWindow::sceneGraphInitialized,
+            this, &LauncherMainWindow::renderTheadSceneGraphInitialized,
+            Qt::DirectConnection);
+
     if (!inSimMode) {
 #if defined(Q_OS_MAC)
         QMenuBar* mb = new QMenuBar();
@@ -195,3 +205,28 @@ bool LauncherMainWindow::execInApp()
     return m_controller->inAppResult();
 }
 
+// this slot runs in the context of the render thread. Don't modify
+void LauncherMainWindow::renderTheadSceneGraphInitialized()
+{
+    auto qContext = QOpenGLContext::currentContext();
+    if (!qContext) {
+        qWarning() << Q_FUNC_INFO << "No current OpenGL context";
+        return;
+    }
+
+    std::string renderer = (char*)glGetString(GL_RENDERER);
+    // capture this to help with debugging this crash:
+    // https://sentry.io/share/issue/f98e38dceb4241dbaeed944d6ce4d746/
+    // https://bugreports.qt.io/browse/QTBUG-69703
+    flightgear::addSentryTag("qt-gl-vendor", (char*)glGetString(GL_VENDOR));
+    flightgear::addSentryTag("qt-gl-renderer", renderer.c_str());
+    flightgear::addSentryTag("qt-gl-version", (char*)glGetString(GL_VERSION));
+    flightgear::addSentryTag("qt-glsl-version", (char*)glGetString(GL_SHADING_LANGUAGE_VERSION));
+
+    const char* gltype[] = {"Desktop", "GLES 2", "GLES 1"};
+    flightgear::addSentryTag("qt-gl-module-type", gltype[QOpenGLContext::openGLModuleType()]);
+
+    // if necessary, borrow more code from:
+    // https://code.qt.io/cgit/qt/qtbase.git/tree/examples/opengl/contextinfo/widget.cpp?h=5.15#n358
+    // to expand what this reports
+}

src/GUI/LauncherMainWindow.hxx

@@ -51,6 +51,7 @@ public:
 
 private slots:
     void onQuickStatusChanged(QQuickView::Status status);
+    void renderTheadSceneGraphInitialized();
 
 private:
     bool checkQQC2Availability();

src/GUI/QtLauncher.cxx

@@ -25,21 +25,23 @@
 #include <locale.h>
 
 // Qt
-#include <QtGlobal>
-#include <QString>
-#include <QProgressDialog>
+#include <QApplication>
+#include <QDebug>
 #include <QDir>
 #include <QFileInfo>
-#include <QTimer>
-#include <QDebug>
-#include <QSettings>
-#include <QUrl>
-#include <QApplication>
-#include <QThread>
-#include <QProcess>
-#include <QTranslator>
 #include <QMessageBox>
+#include <QOffscreenSurface>
+#include <QOpenGLContext>
 #include <QPointer>
+#include <QProcess>
+#include <QProgressDialog>
+#include <QSettings>
+#include <QString>
+#include <QThread>
+#include <QTimer>
+#include <QTranslator>
+#include <QUrl>
+#include <QtGlobal>
 
 // Simgear
 #include <simgear/timing/timestamp.hxx>
@@ -247,6 +249,35 @@ private:
     bool m_abandoned = false;
 };
 
+bool checkForWorkingOpenGL()
+{
+    QSurfaceFormat fmt;
+    fmt.setProfile(QSurfaceFormat::CompatibilityProfile);
+    fmt.setMajorVersion(2);
+    fmt.setMinorVersion(1);
+
+    QOpenGLContext ctx;
+    ctx.setFormat(fmt);
+    if (!ctx.create()) {
+        return false;
+    }
+
+    QOffscreenSurface offSurface;
+    offSurface.setFormat(ctx.format()); // ensure it's compatible
+    offSurface.create();
+    if (!ctx.makeCurrent(&offSurface)) {
+        return false;
+    }
+
+    std::string renderer = (char*)glGetString(GL_RENDERER);
+    if (renderer == "GDI Generic") {
+        flightgear::addSentryBreadcrumb("Detected GDI generic renderer", "info");
+        return false;
+    }
+
+    return true;
+}
+
 } // of anonymous namespace
 
 static void initQtResources()
@@ -411,6 +442,7 @@ void initQSettings()
         qRegisterMetaType<QuantityValue>();
         qRegisterMetaTypeStreamOperators<QuantityValue>("QuantityValue");
 
+
         qSettingsInitDone = true;
         string fgHome = globals->get_fg_home().utf8Str();
 
@@ -501,6 +533,13 @@ void launcherSetSceneryPaths()
 
 bool runLauncherDialog()
 {
+    if (!checkForWorkingOpenGL()) {
+        QMessageBox::critical(nullptr, "Failed to find graphics drivers",
+                              "This computer is missing suitable graphics drivers (OpenGL) to run FlightGear. "
+                              "Please download and install drivers from your graphics card vendor.");
+        return false;
+    }
+
     // Used for NavDataCache initialization: needed to find the apt.dat files
     launcherSetSceneryPaths();
     // startup the nav-cache now. This pre-empts normal startup of