[PATCH] Add language about implicit flush and command completion

[Michel Dänzer]

On Fri, 2009-01-09 at 18:32 -0800, Ian Romanick wrote:
> Copied language from the glXSwapBuffers manual page about the implicit
> glFlush and expected command completion.  This just codifies what
> people already expect from glXCopySubBufferMESA.  The intention of
> this command is to work like glXSwapBuffers but on a sub-rectangle of
> the drawable.

[...]

> +    glXCopySubBufferMESA performs an implicit glFlush before it
> +    returns.  Subsequent OpenGL commands may be issued immediately
> +    after calling glXCopySubBufferMESA, but are not executed until the
> +    copy is completed. 

Note that the GLX spec is a little more complicated wrt this, it says:

        If dpy and draw are the display and drawable for the calling
        thread’s current context, glXSwapBuffers performs an implicit
        glFlush.

(I think the Mesa glXSwapBuffers code doesn't currently conform to this
but unconditionally performs the implicit glFlush)


-- 
Earthling Michel Dänzer           |                http://www.vmware.com
Libre software enthusiast         |          Debian, X and DRI developer