Multisampling: QSurfaceformat::samples() always returns -1

sylorr

Hi all,

I am using QOpenGLWidget to render 3D scene and I want to turn on MSAA even before my App is running.

This is what I do now:

SurfaceFormat format;
format.setRenderableType(QSurfaceFormat::OpenGL);
format.setVersion(3, 3);
format.setProfile(QSurfaceFormat::CoreProfile);
format.setSwapBehavior(QSurfaceFormat::DoubleBuffer);
int samples = format.setSamples(8)
// int samples = format.samples()

However, either samples() or setSamples(int) returns -1. I wonder if I need to turn on something from OpenGL side. Therefore I did this before setting up format:

initializeOpenGLFunctions();
glEnable(GL_MULTISAMPLE);

As you may guess, setSamples(8) still returns -1. I begin to doubt if my system doesn't support MSAA at all. But I don't know how to check it. Could you please help me out? Either checking if my system could support multisampling or the correct way to use multisampling. Thanks

Note: Platform: Qt5.6 + Ubuntu16.04 + C++14