CEGUI (Crazy Eddie's GUI) Forums

So I've got CEGUI rendering, but it only renders the first frame of my application. After that it's as though the window is destroyed.

If I turn off my render loop, I can see my window, but as soon as I render my second frame, the CEGUI window goes away. With the render loop running I see a flash of the window before it disappears.

I have the call to CEGUI::System::getSingleton().renderAllGUIContexts() as the last thing in my render funtion before the buffer swap, what's the dumb mistake I'm making?

CEGUI log file:

How do you render? We need to see your loop from which you call CEGUI.

What is important to know is if any state changes you make could affect CEGUI. Does CEGUI render correctly if you just make a loop containing the CEGUI update and render call?

Lucebac made application templates, you might wanna compare the loops based on those:
SDL2: https://bitbucket.org/lucebac/cegui/src ... s/SDL2.cpp
GLFW3: https://bitbucket.org/lucebac/cegui/src ... /glfw3.cpp

ok, relevent bits of my code:



I'm not sure how much of that is relevent though, as I render CEGUI last, and it does render the first time through.

If I comment out all of from the pre-draw loops to the post-draw loops then CEGUI does seem to render ok.

So, what am I not turning off?

Illiander wrote:If I comment out all of from the pre-draw loops to the post-draw loops then CEGUI does seem to render ok.

So, what am I not turning off?

If you only render CEGUI and it renders fine (not just one frame but permanently - which you know once you render the mouse cursor or interact with CEGUI visibly) then the issue is your OpenGL states.


OpenGL has a lot of states and with every new OpenGL version there are new ones. Therefore we cannot possibly set all of them back for you. You need to do that yourself. Also if we did that the costs would be ridiculous.

You can use gdebugger to debug OpenGL. THis allows you to check what states you change after rendering. Once you know what you change from its default, you will know what might need to be changed back to default for CEGUI. You seem to use vbos but not vaos, is that correct? If yes please use vao, thats cleaner.
Try the following things:
before rendering CEGUI, order shouldnt matter:


Report any changes

No changes with that.

I'm pretty sure it's not an OpenGL state issue I'm getting, as when I set one of my key handlers to create a CEGUI window, then that one also shows up for exactly one frame (if I create a new window every frame, then it looks like I've got it sticking around, until I look at my memory usage)

I haven't gotten to the bit of the tutorials where you inject inputs yet, so I can't see the CEGUI cursor.

But you said if you comment out all other rendering stuff then CEGUI renders fine. So either CEGUI is effectively not re-rendered ever or I dont understand what is going on. Are you updating it correctly? You need to inject time to System and GUIContext if I remember right: consult the api docs: http://static.cegui.org.uk/docs/0.8.4/i ... orial.html

If I comment out all the other rendering stuff then I get a CEGUI window on my screen in the right place, and it redraws when I resize the window.

If I only render the first frame, then I get a CEGUI window over my scene looking correct, but it doesn't redraw when I resize the window.

If I have everything there, then I get a CEGUI window for the first frame (I slowed down my framerate to check) then the CEGUI window disappears. If I have an event create another CEGUI window, then that one also appears for a single frame.

I was under the impression that CEGUI would render correctly without needing any inputs injecting, including time. If I need to inject time in order to get things to show up for more than one frame, I can do that, I was just trying to get one thing working before I started on the next.

Injecting time pulses should be enough, this is basically the update-call. You do not need to inject inputs. You can also inject 0.f as timepulse. Please tell me if it changes anything.

Injecting a time pulse of 0 every frame does the job.

Thanks.