OpenGL Dynamic selected driver

QbProg

Hello,
is there a way to detect the current opengl implementation used between desktop , angle, software?
I see a way to force the selection (using attributes), but not a direct way to detected the selected implementation.

I would like to detect if I'm using desktop opengl because I need to workaround the fullscreen + dialogs bug.

Thank you
QbProg

ceora

If you are using QCoreApplication or QApplication, you can testit like this

@QCoreApplication a(argc,argv);//in main

bool test = a.testAttribute(Qt::AA_UseDesktopOpenGL);

//or somewhere else in the code:
bool test = qApp->testAttribute(Qt::AA_UseDesktopOpenGL);
@

QbProg

unfortunately that doesn't seem to work, as these flags are used to force the loading behavior, but when you read them they are always false (of course with a QML scene already loaded).

ceora

Strange, for me work(I don't use QML)... Which version of Qt do you have??
using this piece of code it give me true on test:

@
#include <QApplication>
#include <QOpenGLWidget>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
a.setAttribute(Qt::AA_UseDesktopOpenGL);

QSurfaceFormat fmt;
fmt.setDepthBufferSize(24);
fmt.setVersion(3, 2);
fmt.setProfile(QSurfaceFormat::CoreProfile);

QSurfaceFormat::setDefaultFormat(fmt);

bool test = a.testAttribute(Qt::AA_UseDesktopOpenGL);
QOpenGLWidget w;
w.show();

return a.exec();
}@

play with commenting , uncommenting the line with setAttribute, test give tru if the line is uncommented, false if is commented, as expected.

agocs

Query format() from the QOpenGLContext after create(). Then check renderableType() to differentiate between OpenGL and OpenGL ES (ANGLE).

As for differentiating between (non-ANGLE) OpenGL implementations, it's more tricky since there's no difference from Qt's point of view. However, you can still query strings like GL_RENDERER and look for "llvmpipe".

The example qtbase/examples/opengl/contextinfo may be a useful tool and reference for doing such checks.