Merge branch 'check_glcontext_on_startup' into 'master'

Check glcontext on startup

See merge request !94

OpenFlipper.cc

@@ -565,6 +565,38 @@ int main(int argc, char **argv)
     QOpenGLContext::globalShareContext()->makeCurrent(surface);
 
 
+    // The opengl surface properties that have actually been applied
+    // (does not necessarily match the requested properties)
+    QSurfaceFormat actuallyAppliedFormat = QOpenGLContext::globalShareContext()->format();
+    auto curVersion = actuallyAppliedFormat.version();
+
+    // Check whether the actually applied OpenGL context matches the requested one.
+    // If not, print some error to the console
+    if(curVersion.first != version.first ||
+       curVersion.second != version.second ||
+       format.profile() != actuallyAppliedFormat.profile())
+    {
+        auto reqProfileString = "None";
+        if(format.profile() == QSurfaceFormat::CoreProfile)
+            reqProfileString = "Core";
+        else if(format.profile() == QSurfaceFormat::CompatibilityProfile)
+            reqProfileString = "Compat";
+
+        auto curProfileString = "None";
+        if(actuallyAppliedFormat.profile() == QSurfaceFormat::CoreProfile)
+            curProfileString = "Core";
+        else if(actuallyAppliedFormat.profile() == QSurfaceFormat::CompatibilityProfile)
+            curProfileString = "Compat";
+
+        std::cerr << "Warning! OpenGL version " << version.first << "."
+                  << version.second << " (" << reqProfileString << ")"
+                  << " was requested, but version " << curVersion.first << "."
+                  << curVersion.second << " (" << curProfileString << ")"
+                  << " was applied." << std::endl;
+        std::cerr << "Please consider setting supported OpenGL version and context in the Options dialog." << std::endl;
+    }
+
+
     if ( !QGLFormat::hasOpenGL() ) {
       std::cerr << "This system has no OpenGL support.\n";
       return -1;