[x11drv] d3d stencil support

[Oliver Stieber]

--- "Adam D. Moss" <aspirin at ntlworld.com> wrote:

> Oliver Stieber wrote:
> > The fallback is there because 1 bit stencil is the
> > minimum required by the opengl specification, so
> it is
> > possible that somewhere there is a driver that
> only
> > supports 1 bit stencil.
> 
> I understood that, I was simply saying that I don't
> think
> there's ever been a consumer graphics card that did
> only
> 1-7 bits -- they seem to universally do 0 or 8 bits
> of
> stencil (even the software-renderers), so the
> fallback is
> likely a waste of breath, though I appreciate
> caution.
> 
> Perhaps more to the point, does D3D only guarantee a
> 1-bit stencil buffer?  A 1-bit stencil buffer (most
> especially one without GL_EXT_stencil_wrap) is of
> very,
> very limited use.  I somewhat expect that no D3D
> applications
> (except maybe, just maybe, some very simple
> test-apps)
> will actually operate correctly with a 1-bit
> unwrapped
> stencil.
>

I haven't come across any yet, but I've mainly been
concentrating on d3d9. there's a good chance that some
older applications may use a 1bit stencil to speed
things up. applications that would generally be
regarded as 2d can make use of a 1bit stencil buffer
for masks and screen wipes.

e.g. http://www.mvps.org/directx/articles/wipe/
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/directx9_c/directx/graphics/programmingguide/advancedtopics/stencilbuffer/dissolvesfadesandswipes.asp


I wouldn't expect someone with hardware that doesn't
support 8bit+ stencils to be playing the latest games,
but there's potential for them to be using other
applications that require a simple stencil buffer, or
simple 3D an no stencil at all, in which case they
require some kind of fallback.



> Cheers,
> --adam
> 
> 
> 




	
	
		
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