SFML - How to put 2D UI over rendering

[mkawick]

I've done a lot of UI programming in the past and certainly a lot of OpenGL. But How would I combine images, buttons, and other UI elements over a rendered OpenGL scene?

Basically, I'd like to know whether to use RenderWindow or Window, how to layer this over a OpenGL scene, and any other relevant setup to combine the two.

Demos or source examples are very helpful. Also, when doing game state management, does the front end have one set of SFML objects that need to be created and deleted, or can I simply hide those layers as a player moves thought the UI.

[helios]

I don't know how it's done in SFML, but in OpenGL basically what you do is, after drawing the 3D portion of the image, reset the MODELVIEW matrix for 2D rendering. Most importantly, this involves setting the projection transformation to orthographic and setting the view frustum to coincide with the screen dimensions. This last detail is not required, but it helps to have view coordinates be the same as screen coordinates. After that, you just draw as you would normally draw in 2D.

See Beginning OpenGL Game Programming for more detailed information.