SIGGRAPH 2018

About 2 weeks ago, I attended SIGGRAPH 2018. I am still very excited about the whole event, and I am very thankful that Igalia (the consultancy company I work for) and specifically the Graphics Team selected me to go, despite this being my first year at the company!  😀

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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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Install/Update LetsEncrypt certificates (no-root, apache2, debian)

It seems that the certbot, the recommended script to install and update the LetsEncrypt certificates requires root permissions. Well, I found several tutorials and forums where people claimed that they ran it without root permissions but they all said they needed root permissions to do something else for certbot to work and then I ran this simple command:

$ ./certbot-auto --help
Requesting to rerun ./certbot-auto with root privileges...
[sudo] password for eleni:

and decided to give up and search for an alternative method. 🙂

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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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Creating cube map images from HDR panoramas on GNU/Linux

As part of my work for Igalia I wanted to do some environment mapping. I was able to find plenty of high quality .hdr images online but I couldn’t find any (OSS) tool to convert them to cubemap images. Then, Nuclear (John Tsiombikas) gave me the solution: he wrote a minimal tool that does the job quickly and produces high quality cube maps.

So, here’s a short “how to” create cubemaps on Linux using his “cubemapper” program in combination with other OSS tools:

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