When increasing QOpenGLWidget size to very large values the widget ceases to render.

This can be tested by running the OpenGLWindow example and calling resize() with high values.

On Mac with AMD Radeon R9 M395 with 2048 MB the max width is 8192 so this limit seems be be related to texture size (though GL Reports max texture size for the platform at 16384).

Could simply be that the limitation needs to be added to the documentation.