Bug 35144

Summary:	r300g should advertise GL_ARB_half_float_vertex on rv350
Product:	Mesa	Reporter:	almos <aaalmosss>
Component:	Drivers/Gallium/r300	Assignee:	Default DRI bug account <dri-devel>
Status:	RESOLVED NOTABUG	QA Contact:
Severity:	normal
Priority:	medium
Version:	unspecified
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:
Attachments:	halffloat.diff

Description almos 2011-03-09 04:57:59 UTC

Created attachment 44273 [details] [review]
halffloat.diff

The windows driver does advertise this extension. As the attached patch shows, the comment in the code already says it should be supported, but the chip revision check is incomplete.

I couldn't test the patch, as the only program actually using this extension that I know of is unigine, but it also needs GL_EXT_texture_swizzle (which is supported by the windows driver).

Comment 1 Marek Olšák 2011-03-09 07:11:42 UTC

rv350 really can't do ARB_half_float_vertex. I tested it on RV350 long time ago and it locked up pretty hard. fglrx lies and uses some fallback probably. If you really need this extension, I can enable the fallback for r300g too.

r3xx cannot do GL_EXT_texture_swizzle with compressed textures, so it's disabled if the S3TC lib is available and enabled otherwise. fglrx here lies again and I don't think they use any kind of fallback.

Comment 2 almos 2011-03-09 09:52:44 UTC

(In reply to comment #1)
> rv350 really can't do ARB_half_float_vertex. I tested it on RV350 long time ago
> and it locked up pretty hard. fglrx lies and uses some fallback probably. If
> you really need this extension, I can enable the fallback for r300g too.
It's not terribly important. I just noticed this inconsistency and decided to ask if it is known. The fallback would be useful only if there were some really important applications (like compiz or googleearth) requiring this extension, but I don't think there are any.

> r3xx cannot do GL_EXT_texture_swizzle with compressed textures, so it's
> disabled if the S3TC lib is available and enabled otherwise. fglrx here lies
> again and I don't think they use any kind of fallback.
Sounds nasty. Maybe these quirks should be documented somewhere...

Comment 3 Marek Olšák 2011-03-10 21:33:39 UTC

I am closing this bug.

Let me know if you need any of those extensions. RV350 is too slow for unigine anyway.

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