OpenGL conformance and liability

[arekkusu]

The ARB FAQ says that hardware vendors are required to pass the OpenGL conformance tests and submit the results back to the ARB in order to use the OpenGL logo.

I have some questions about this:

1. What OpenGL features do the conformance tests cover?
2. Are the conformance tests downloadable by the public for independent testing?
3. Are the submitted results viewable by the public?
4. If the vendor claims conformance, but their implementation is then found to be non-conformant, is there any liability?

I am asking this because Apple Computer ships current machines (Aluminum Powerbooks, G5s) with the ATI Radeon 9600, which claims to implement OpenGL 1.3 and to be “OpenGL Compliant”. Apple uses the OpenGL logo on their page, along with blurbs such as “The PowerBook G4’s graphics processors take full advantage of OpenGL, an advanced 3D technology — which runs even faster under Mac OS X Panther v10.3.” Clearly Apple Computer wants their customers to believe they are conformant.

However, this is not true. Specifically, the shipping driver in Mac OS X 10.3 for the ATI Radeon 9600 does not implement line stipple or polygon stipple, which are basic features of OpenGL 1.0. Reading the OpenGL spec, it appears to me that these features MUST be implemented to claim compliance: Appendix A, “Invariance: … GL implementations are required to implement ALL GL capabilities, not just a convenient subset…”

Additionally, the same driver does not implement point, line, or polygon antialiasing. Here the wording of the spec is not entirely clear to me, it states (re: lines) “Not all widths need be supported for line segment antialiasing, but width 1.0 antialiased segments must be provided” which implies that antialiasing support is required. But it also says that the details of the antialiasing coverage calculation are implementation dependent, subject to a few rules. It may be that aliased rendering is still compliant to the letter of those rules, if not the spirit.

[This message has been edited by arekkusu (edited 11-30-2003).]

[arekkusu]

Belated followup in case anyone cares,

I got a reply from arb-secretary@sgi.com, which I will summarize here.

1. This information is not publicly available. But, there is a small “must pass” core test, and a number of optional tests which a vendor is allowed to fail and still claim conformance. Line / polygon stipple fall into this latter category.

2. No. The tests are available only to SGI’s OpenGL licensees.

3. No.

4. Generally, the market is left to govern itself in the case of poor quality implementations. But SGI will step in if a vendor is obviously misusing the trademark.