What disadvantages could I have using OpenGL for GUI design in a desktop application? [closed]

Question

There are tons of GUI libraries for C/C++, but very few of them are based on the idea that opengl is a rather multiplatform graphics library. Is there any big disadvantage on using this OpenGL for building my own minimal GUI in a portable application?

Blender is doing that, and it seems that it works well for it.

EDIT: The point of my question is not about using an external library or making my own. My main concern is about the use of libraries that use opengl as backend. Agar, CEGUI or Blender's GUI for instance.

Thanks.

Answer 1

Here's an oddball one that bit a large physics experiment I worked on: because an OpenGL GUI bypasses some of the usual graphics abstraction layers, it may defeat remote viewing applications.

In the particular instance I'm thinking of we wanted to allow remote shift operations over VNC. Everything worked fine except for the one program (which we only needed about once per hour, but we really needed) that used an OpenGL interface. We had to delay until a remote version of the OpenGL interface could be prepared.

Answer 2

You're losing the native platforms capabilities for accessibility. For example on Windows most controls provide information to screen readers or other tools supporting accessibility impaired users.

Basically unless you have a real reason to do this, you shouldn't.