OpenGL Floating Point Textures No Longer Encumbered By Patents, Enabled In Mesa

Back in 2012 when talking with Gabe Newell of Valve about open-source/Linux challenges one of the topics he was awed about was patents encumbering the open-source graphics driver progress. Six years later, Timothy Arceri working on the Valve Linux graphics driver team has freed Mesa's ARB_texture_float support from being built conditionally due to these patent fears.

Arceri on behalf of Valve committed a change to now unconditionally enable OpenGL floating point textures now that the Silicon Graphics patent should be expired.

ARB_texture_float references US Patent #6,650,327 [1] which has a filing date of June 16 1998.

According to [2], patents filed after 1995 expire 20 years from the filing date, giving an expiration of June 17 2018.

[1] https://www.google.com/patents/US6650327
[2] https://en.wikipedia.org/wiki/Term_of_patent_in_the_United_States

The OpenGL ARB_texture_float extension has been one of the royal pains for open-source software:

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 capabilities.

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.

Support for this OpenGL extension was merged back in 2011 but disabled by default up until now. ARB_texture_float is one of the requirements of OpenGL 3.0.