i965: Improved support for the ETC/EAC formats on Intel Gen 7 and previous GPUs

This post is about a recent contribution I’ve done to the i965 mesa driver to improve the emulation of the ETC/EAC texture formats on the Intel Gen 7 and older GPUs, as part of my work for the Igalia‘s graphics team.

Demo:

The video mostly shows the behavior of some GL calls and operations with and without the patches that improve the emulation of the ETC/EAC formats on Gen7 GPUs. The same programs run first with the previous ETC/EAC emulation (upper terminal) and then with the new one (lower terminal).

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Hair simulation with a mass-spring system (punk’s not dead!)

Hair rendering and simulation can be challenging, especially in real-time. There are many sophisticated algorithms for it (based on particle systems, hair mesh simulation, mass-spring systems and more) that can give very good results. But in this post, I will try to explain a simple and somehow hacky approach I followed in my first attempt to simulate hair (the mohawk hair of the video below) using a mass-spring system.


 

The code can be found here: https://github.com/hikiko/mohawk

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Claws-mail: a trick to view the patches as side-by-side diffs

One thing that I find very tiring when I read the Mesa3D mailing list for my work at Igalia , is to read the patches that arrive as emails: they are too many and the mail clients do not highlight them. So far, I was using the thunderbird mail-client with the colored-diffs plugin that made them more readable, but it was quite slow and was breaking the appearance of the e-mails that were replies to a patch. Since, I never was a big fan of thunderbird (the list of the things I disliked about it was always longer than the list of the features I liked) I wanted to find a way to have the colored-diffs and the lightning plugins functionalities to a more lightweight gui-mail-client: the claws-mail.

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A short OpenGL / SPIRV example.

It’s been a while since Igalia is working on bringing SPIR-V to mesa OpenGL. Alejandro Piñeiro has already given a talk on the status of the ARB_gl_spirv extension development that was very well received at FOSDEM 2018 . Anyone interested in technical information can watch the video recording here: https://youtu.be/wXr8-C51qeU.

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Fosscomm 2017 [update: slides in English]

FOSSCOMM (Free and Open Source Software Communities Meeting) is a Greek conference aiming at free-software and open-source enthusiasts, developers, and communities. The event is solely organized and ran by volunteers (usually university students, communities, Linux User Groups) and is taking place in a different city every year. The attendance is free and everyone is welcome to make a presentation or a workshop related to free and open source projects.

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A terrain rendering approach (part 1)

There are several methods to create and display a terrain, in real-time. In this post, I will explain the approach I followed on the demo I’m writing for my work at Igalia. Some work is still in progress.

The terrain had to meet the following requirements:

  • its size should be arbitrary
  • parts outside the viewer’s field of view should be culled

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Debugging graphics code using replacement shaders (Linux, Mesa)

Sometimes, when working with the mesa drivers, modifying or replacing a shader might be extremely useful for debugging. Mesa allows users to replace their shaders at runtime without having to change the original code by providing these environment variables:

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