Is it possible to use OpenGL in a window that is already using GDI+ ?

Question

Basically I am being called to render to an offscreen DC which is set up (I'm not sure how) to use GDI+. When I try to associate an OpenGL context with the DC, it just fails (i.e. returns zero but no error). SetPixelFormat also fails (probably because it is already set up?), again by returning zero, not an error.

Anyone know whether it is possible, given such a situation (i.e. offscreen context for a window into which someone else is using GDI+), to create an OpenGL context and use OpenGL for my own rendering? (And if it is possible, why might the wglCreateContext be failing?)

Answer 1

This article shows you all of the steps to hook up a GDI window: http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=01

Essentially, you have to:

1. Create a window
2. Register the window
3. Get the device context of the window's drawing area
4. Setup the pixel format for the device context
5. Call wglCreateContext
6. Call wglMakeCurrent
7. Display the window

If you already have access to the device context, skip the first two steps.

In your case, you might see if wglMakeCurrent is all you need. Otherwise, you might want to post more details about the errors and behaviors you are experiencing.