mesa3d-users

[Mesa3d-users] How do I copy a buffer from win32 window

[vinit b. <ban...@gm...>]

Hi,

I'm a novice to openGL. My objective is to create a win32 Window,
render some image onto it and want to copy it's framebuffer.

I followed some simple steps referring
http://msdn.microsoft.com/en-us/library/ms970779.aspx.
1) Got DC through GetDC() from win32 window.
2) Create Wgl context using that DC.
3) Make it the current rendering context using WglMakeCurrent.
4) Then I called some OpenGL calls.
5) After that I say WglSwapBuffer to display on that window.
Upto this point, there is no problem.

But i want to capture the framebuffer of that win32 window so that i
can copy it to another buffer.
Wgl doesnot provide any api like EGL does i.e. EglCopyBuffers().

How can I achieve this in case of WGL?

Re: [Mesa3d-users] How do I copy a buffer from win32 window

[tom f. <tf...@al...>]

vinit bansal <ban...@gm...> writes:
> I'm a novice to openGL. My objective is to create a win32 Window,
> render some image onto it and want to copy it's framebuffer.
[snip]
> But i want to capture the framebuffer of that win32 window so that i
> can copy it to another buffer.  Wgl doesnot provide any api like EGL
> does i.e. EglCopyBuffers().

You can do this in straight gl.   See `glReadPixels'.

Might want to look at framebuffer objects / renderbuffers if this is a
common use case for you.

-tom