Different surface types

[Brian Paul]

Jon Smirl wrote:
> On 4/30/05, Brian Paul <brian.paul at tungstengraphics.com> wrote:
> 
>>>Would the standalone world be simpler if there was just one kind of
>>>surface that migrated to VRAM if it is going to be used?
>>
>>I don't know.  But I like the idea of separate types/functions for
>>Pbuffers and screen surfaces because PBuffers have traditionally
>>always been known as off-screen surfaces and there's some pbuffer
>>operations (such as binding to textures) which don't seem appropriate
>>for screen surfaces.
> 
> 
> Why can't a screen surface be bound as a texture, for example a screen
> magnifier?

I imagine that could be done with some hardware, but perhaps not with 
others (for all sorts of reasons).

If you want to explore how this could be accomodated with 
EGL_MESA_screen_surface, feel free.  The existing EGL functions for 
binding texture images to surfaces don't appear to to prevent this.  A 
layered extension such as EGL_MESA_screen_texture could expose the 
capability with little or no new API additions.

-Brian