1. Computers
  2. Display Drivers
  3. Graphics Cards
  4. Memory
  5. Motherboards
  6. Processors
  7. Software
  8. Storage
  9. Operating Systems


Facebook RSS Twitter Twitter Google Plus


Phoronix Test Suite

OpenBenchmarking.org

What Was Decided With S3TC & Floating Points For Mesa

Mesa

Published on 09 March 2011 08:25 AM EST
Written by Michael Larabel in Mesa
23 Comments

Last week I mentioned that a developer called for a discussion about merging the OpenGL floating point textures and render targets branch into mainline Mesa. This code has been ready for a while but hasn't been merged due to patent concerns, but to alleviate that while pushing the code forward, the proposed idea was to add a --enable-patented build option. Over the weekend, the discussion continued and it was then also proposed to merge the S3TC texture compression work (another feature where developers are concerned about patent infringement) and to conceal that behind the new build option too. So what happened since and did the work make it into the mainline Mesa Git repository?

On Monday, VMware's Jose Fonseca didn't outright reject the floating point work (email), but as far as the implementation impacting LLVMpipe are implemented, he doesn't want that driver to have the support in its current form. The reason for this is not due to legal concerns with VMware developing the LLVMpipe driver, but because of performance reasons for how it's implemented right now with the most common textures being slower. In fact, Jose is fine with the branch being merged and the OpenGL floating point extensions being enabled by default for LLVMpipe, Softpipe, and the classic Mesa software rasterizer. These are all of the Mesa / Gallium3D drivers that don't work in tandem with a GPU but rather are software/CPU-based.

How can they get away with enabling it by default for software drivers without worrying about legal backlash? Because there is prior art of sampling/rendering floating point textures purely in software, which is admitted by the patent holder. For the hardware drivers is where it becomes a different story.

David Airlie commented on the proposal to merge the libtxc_dxtn (S3TC) library into Mesa to basically counter this idea. With the S3TC library, it's built as a separate library that can plug-in to Mesa. This isn't possible with the floating point work, which is why it needs to be integrated with core Mesa. By integrating the S3TC library into core Mesa, it then means users must always rebuild Mesa rather than just dropping in a shared library. Users right now need to build the S3TC library anyways since the library can't be redistributed in binary form.

But that's basically been about it as far as the S3TC / floating point Mesa discussion has gone in recent days; the discussion has basically died yet again.

About The Author
Michael Larabel is the principal author of Phoronix.com and founded the web-site in 2004 with a focus on enriching the Linux hardware experience and being the largest web-site devoted to Linux hardware reviews, particularly for products relevant to Linux gamers and enthusiasts but also commonly reviewing servers/workstations and embedded Linux devices. Michael has written more than 10,000 articles covering the state of Linux hardware support, Linux performance, graphics hardware drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated testing software. He can be followed via and or contacted via .
Latest Linux Hardware Reviews
  1. 13-Way Low-End GPU Comparison With AMD's AM1 Athlon
  2. ASUS AM1I-A: A Mini-ITX Board For Socketed Kabini APUs
  3. Mini-Box M350: A Simple, Affordable Mini-ITX Case
  4. Overclocking The AMD AM1 Athlon & Sempron APUs
Latest Linux Articles
  1. How Much Video RAM Is Needed For Catalyst R3 Graphics?
  2. Ubuntu 12.04 LTS vs. 14.04 LTS Cloud Benchmarks
  3. Ubuntu 12.04.4 vs. 13.10 vs. 14.04 LTS Desktop Benchmarks
  4. AMD OpenCL Performance With AM1 Kabini APUs
Latest Linux News
  1. ReactOS Working On A Community Windows OS
  2. Borderlands Is Being Considered For Linux
  3. Mesa 10.0 & 10.1 Stable Get Updated
  4. Getting Hit By The Variable Performance Of The Public Cloud
  5. Git 2.0 Test Releases Begin With Many Changes
  6. Wine 1.7.17 Works On Its Task Scheduler, C Run-Time
  7. The Improv ARM Board Still Isn't Shipping; Riding A Dead Horse?
  8. Debian To Maintain 6.0 Squeeze As An LTS Release
  9. Wasteland 2 Is Finally Released For Linux Gamers
  10. FreeBSD Advances For ARM, Bhyve, Clang
  11. Ubuntu 14.04 LTS "Trusty Tahr" Officially Released
  12. Ubuntu 12.04 LTS vs. 14.04 LTS Server Benchmarks
Latest Forum Discussions
  1. Updated and Optimized Ubuntu Free Graphics Drivers
  2. Catalyst 14.3 Beta
  3. Suggestions about how to make a Radeon HD 7790 work decently?
  4. The GNOME Foundation Is Running Short On Money
  5. Radeon 8000M problematic on Linux?
  6. Linux Kernel Developers Fed Up With Ridiculous Bugs In Systemd
  7. After Jack Keane, RuseSoft will briing Ankh 3 to Linux through Desura
  8. Suspected PHP Proxy Issue