On 11/12/2013 12:35 PM, Paul Berry wrote: > On 12 November 2013 12:13, Kenneth Graunke <kenn...@whitecape.org > <mailto:kenn...@whitecape.org>> wrote: > > It would be great to put a citation for this: > > /* From the ARB_multi_draw_indirect specification: > * "INVALID_VALUE is generated by MultiDrawArraysIndirect or > * MultiDrawElementsIndirect if <primcount> is negative." > * > * "<primcount> must be positive, otherwise an INVALID_VALUE error will > * be generated." > */ > > These beg the question of whether 0 is allowed. Usually I interpret > "negative" as < 0, "positive" as >= 0, and "strictly positive" as > 0. > So I think zero should be allowed, and I don't see a contradiction. > > The only text I can find in 4.3 and 4.4 just reiterate that it needs to > positive, and I don't see any text defining "positive." > > > In the absence of text defining "positive", shouldn't we go with the > definition used by mathematicians? According to > http://en.wikipedia.org/wiki/Sign_%28mathematics%29#Terminology_for_signs, > "positive" means strictly greater than zero.
Mathematicians are inconsistent in their use of terminology. Positive can mean either > 0 or >= 0 depending who you talk to and in what context. And the GL specification authors are notoriously non-precise. > If anyone is aware of a competing implementation that accepts a > primcount of 0, then I'd be open to following the behaviour of the > competing implementation (and filing a spec bug). But otherwise I think > we should prohibit zero. Then I suppose I have to go test AMD or nVidia. > (Note: I brought this up last time the patch was reviewed: > http://lists.freedesktop.org/archives/mesa-dev/2013-November/047962.html) _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
