It’s been a few weeks I’ve been experimenting with EGL/GLESv2 as part of my work for WebKit (Browsers) team of Igalia. One thing I wanted to familiarize with was using shared DMA buffers to avoid copying textures in graphics programs.
ANGLE is an EGL/GLES2 implementation on top of other graphics APIs. It is mainly used in systems that lack a native GLES2/GLES3 driver and in some browsers for example Chromium. As recently, I’ve used it for some browsers related work in Igalia‘s WebKit team (more on that coming soon) and had to set it up for debugging with GDB, I’d like to share the few extra settings and the configuration I’ve used to be able to use GDB and step inside the ANGLE API calls to examine the underlying driver API calls, when possible, while I was experimenting with ANGLE-based test programs.
More than a year ago, I had worked on the implementation of VK_EXT_sample_locations extension for anv, the Intel Vulkan driver of mesa3D, as part of my work for Igalia. The implementation had been reviewed (see acknowledgments) at the time, but as the conformance tests that were available back then had to be improved and that was work in progress, the feature was stalled, and I had forgotten about it… Until some weeks ago, when I realized that it has been merged into mesa! 🎉
As this feature is now available to the users, I’ve decided to write a short blog post to explain what this extension is about. You can read the extension’s specification if you are interested in learning how to use it and other details.
There’s a lot of documentation online about building Webkit/WPE on Linux. But as most instructions are targetting embedded platforms developers, the focus is on building Webkit with Wayland using the flatpak-sdk to automate and speed up the building process. As the steps I’ve followed to build it on my X11 system and run the Webkit/WPE MiniBrowser on a nested Weston were a bit different from the recommended ones I thought that a blog post about them might be useful to people trying to build WPE/Webkit in platforms lacking Wayland, flatpak, systemd, and modern Desktop Environments like the latest KDE and GNOME.
Be careful though: this is not the recommended way to build WebKit/WPE, only the alternative steps I’ve followed in my personal computer until I have access to a building machine! If you are not sure about what you want to do with WebKit/WPE please take a look at the recommended wiki instructions before you follow mine!
Since some days ago I’ve finished BootBoot, my x86 assembly helloworld, I am posting a quick update on it and I’ll continue the blog posts when I have more time. A demo of it is on youtube:
This is my second post on BootBoot, the “boot loader” I am writing to load the real boot loader after displaying something on screen. I am writing this program for fun, and to learn the x86 assembly basics. I am trying to write one blog post per commit for me to remember what I’ve done next time I need to use assembly, and for any other assembly n00b out there who might be interested in reading my steps.
In this second post, I am going to extend the program of Part 1 to load the second sector, jump to it and clear the screen with a different color after that. If the displayed color is the new one I can validate the jump was successful.
Hi there! This is my first attempt to write a program in x86 assembly. I’ll call it BootBoot and it will be a boot loader that boots a program from the first floppy drive, displays an effect, and then boots grub and the OS. I am going to write a blog post after each commit to remember the steps I followed (hoping that writing my next ASM program will be easier if every step of this one is documented). In this post (part 1) my goal is to load a program that boots from the floppy drive and clears the screen.
FOSSCOMM (Free and Open Source Software Communities Meeting) is a Greek conference aiming to promote the use of FOSS in Greece and to bring FOSS enthusiasts together. It is organized entirely by volunteers and universities and takes place in a different city each year. This year it was virtual as Greece is under lockdown, and although we’ve missed all the fun of the gathering, there were many interesting talks to watch.
My talk was very similar to the one I’ve given in XDC 2020 about OpenGL and Vulkan Interoperability. It was an update on the EXT_external_objects and EXT_external_objects_fd OpenGL extensions status on various mesa drivers, and Igalia‘s work on them.
Vulkan conformance tests for graphics drivers save their output images inside an XML file called
TestResults.qpa. As binary outputs aren’t allowed, these output images (that would be saved as PNG otherwise) are encoded to text using Base64 and the result is printed between
<Image></Image> XML tags. This is a problem sometimes, as external tools are required to display them. In this post I’d like to share a few simple hacks I’m using to display the CTS output as an image immediately after running a CTS test, hoping that they might be handy to more people who work on the drivers.