[Mesa-dev] [RFC] [BRANCH] Floating point textures and rendering for Mesa, softpipe and llvmpipe

Brian Paul brian.e.paul at gmail.com
Wed Sep 1 13:28:04 PDT 2010

On Fri, Aug 27, 2010 at 6:49 AM, Luca Barbieri <luca at luca-barbieri.com> wrote:
> I created a new branch called "floating" which includes an apparently
> successful attempt at full support of floating-point textures and
> render targets.


I've spoken to Luca offline about this.

I'm hesitant to have this work merged into Mesa/master because of the
what's written in the IP status section of the extension spec:

    SGI owns US Patent #6,650,327, issued November 18, 2003. SGI
    believes this patent contains necessary IP for graphics systems
    implementing floating point (FP) rasterization and FP framebuffer

    SGI will not grant the ARB royalty-free use of this IP for use in
    OpenGL, but will discuss licensing on RAND terms, on an individual
    basis with companies wishing to use this IP in the context of
    conformant OpenGL implementations. SGI does not plan to make any
    special exemption for open source implementations.

    Contact Doug Crisman at SGI Legal for the complete IP disclosure.

SGI (aka Rackable Systems) no longer owns this IP.  It now belongs to
an IP holdings company and it appears that organization is still
persuing a lawsuit with AMD/ATI over floating point rendering.

I think we need to be sure we're not infringing on this patent.  Until
we know one way or the other I'd prefer that we don't merge this
branch into master.  In the mean time I'll see if I can learn more
about the situation and find a way to proceed.

IINAL and don't have the answers so I'm not going to get into an
extended discussion about this.


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