Opengl + text

[Srejv]

I was thinking of using SFML for help with text output when coding OpenGL programs,  but do I really have to initialize opengl at every frame if I want to use the sf::String and OpenGL? :S

I don't know how to explain my problem because it's just weird. Right now I'm initiating OpenGL and setting everything up outside the main loop inside "App.StartOpenGL()" and "App.EndOpenGL()" then I'm using the same for drawing geometry inside the main loop, but I don't get any output at all. :s

[Laurent]

I was thinking of using SFML for help with text output when coding OpenGL programs, but do I really have to initialize opengl at every frame if I want to use the sf::String and OpenGL?

Yes. I admit it's not an elegant way to integrate OpenGL stuff into a SFML rendering code ; I have to work more to improve it.

I don't know how to explain my problem because it's just weird. Right now I'm initiating OpenGL and setting everything up outside the main loop inside "App.StartOpenGL()" and "App.EndOpenGL()" then I'm using the same for drawing geometry inside the main loop, but I don't get any output at all. :s

It's often related to texture mapping. Try to reset your texture state before your OpenGL custom rendering.

[Srejv]

I don't know how to explain my problem because it's just weird. Right now I'm initiating OpenGL and setting everything up outside the main loop inside "App.StartOpenGL()" and "App.EndOpenGL()" then I'm using the same for drawing geometry inside the main loop, but I don't get any output at all. :s

It's often related to texture mapping. Try to reset your texture state before your OpenGL custom rendering.

But I'm not using any textures at all.  

[Laurent]

But I'm not using any textures at all

Yes but SFML uses it, so texture mapping is enabled
You should disable it by calling gldisable(GL_TEXTURE_2D) before your OpenGL rendering.

[Srejv]

But I'm not using any textures at all

Yes but SFML uses it, so texture mapping is enabled
You should disable it by calling gldisable(GL_TEXTURE_2D) before your OpenGL rendering.

Ahaa! Well that makes sense. Thanks!

[TMKCodes]

Sorry for bringing up such old topic, but has this had any improvements? I would so love having easy way of rendering text on OpenGL app with C.

[Laurent]

Yes of course. Use RenderWindow::PreserveOpenGLStates(true) to be able to mix SFML and OpenGL in a window.

Have a look at the OpenGL sample from the SDK if you want a working example.

[TMKCodes]

Nice.