OnResize() is not using FramebufferSize property

[DigitalBox98]

The current samples are not handling correctly the resizing of the window :

Current code :
GL.Viewport(0, 0, Size.X, Size.Y);

Proposal for fix :
Vector2i fb = this.FramebufferSize;
GL.Viewport(0, 0, fb.X, fb.Y);

[NogginBops]

Thanks for the report! I had totally forgotten to do this.
Will make a PR for this soon.