wined3d: Bind device framebuffer in ActivateContext

[H. Verbeet]

On 17/12/2007, Allan Tong <actong88 at gmail.com> wrote:
> > > The second patch moves FBO draw buffer selection to ActivateContext.
> > > For onscreen rendering, not much changes except binding framebuffer 0.
> > >  For offscreen rendering, the behavior depends on the specified
> > > context usage.  For BLIT and RESOURCE_LOAD, the target surface is
> > > attached to dst_fbo and used as the draw buffer.  For DRAWPRIM and
> > > CLEAR, I simply call apply_fbo_state.  This assumes that DRAWPRIM and
> > > CLEAR will always be used with device->render_targets[0].
> > There is a problem with GL_COLOR_ATTACHMENT1_EXT and higher, and the depth
> > attachment. You're only applying the first color attachment, but that can
> > lead to incomplete fbos, if for example the render target and depth stencil
> > are changed. If you're only reapplying the first color attachment, you can
> > get a size mismatch, which makes the driver pretty angry and can slow
> > everything down.
>
> As far as I can tell, the only thing that's ever attached to
> device->dst_fbo is the first color attachment, so I wouldn't think
> there's any chance for a size mismatch.  Do I still need to unset the
> depth attachment or the higher color attachments?  I'm assuming
> there's no reason to have a depth attachment for a blit operation.
>
Currently src_fbo and dst_fbo are only used for doing blits between
surfaces in stretch_rect_fbo() and a colorfill in color_fill_fbo(), so
there will only ever be something attached to
GL_COLOR_ATTACHMENT0_EXT.