Incorrect size of opengl viewport

[jonjenssen]

On Windows, if you have another DPI scaling than 100%, the opengl viewport gets wrong size.

[jonjenssen]

Need to scale raw coordinates in caf::Viewer, both for output and mouse input, like:

void RiuViewer::resizeGL( int width, int height )
{
    auto ratio = RiaGuiApplication::instance()->primaryScreen()->devicePixelRatio();
    caf::Viewer::resizeGL( width * ratio, height * ratio );
}

[jonjenssen]

Temporary fix to revert to Qt5 behaviour on Windows:

RiaMain.cpp:

#ifdef WIN32
    // Temporary workaround for incorrect scaling of opengl viewport on windows with dpi scaling != 100%
    // Reverts scaling behaviour to Qt5 style
    // Should be replaced by proper scaling of x and y coordinates in caf::Viewer
    qputenv( "QT_ENABLE_HIGHDPI_SCALING", "0" );
#endif

(Setting env variable before running executable gives mixed results)

[magnesj]

Maybe related to #11889