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.
Continue reading About VK_EXT_sample_locations
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!
Continue reading Build WebKit/WPE on Linux/X11
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.
Continue reading FOSSCOMM 2020, and a status update on EXT_external_objects(_fd) extensions [en, gr]
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.
Continue reading A hack to display the Vulkan CTS tests output
This is 10th post on OpenGL and Vulkan interoperability with EXT_external_objects and EXT_external_objects_fd. We’ll see the last use case I’ve written for Piglit to test the extensions implementation on various mesa drivers as part of my work for Igalia. In this test a stencil buffer is allocated and filled with a pattern by Vulkan and then it is used in OpenGL to render something else. We validate that the pattern has been imported correctly and we repeat the process for other depth-stencil formats.
Continue reading [OpenGL and Vulkan Interoperability on Linux] Part 10: Reusing a Vulkan stencil buffer from OpenGL
In this 9th post on OpenGL and Vulkan interoperability on Linux with EXT_external_objects and EXT_external_objects_fd we are going to see another extensions use case where a Vulkan depth buffer is used to render a pattern with OpenGL. Like every other example use case described in these posts, it was implemented for Piglit as part of my work for Igalia‘s graphics team to check the extensions implementation of various mesa drivers.
Continue reading [OpenGL and Vulkan Interoperability on Linux] Part 9: Reusing a Vulkan z buffer from OpenGL
This is the 8th post on OpenGL and Vulkan Interoperability with EXT_external_objects and EXT_external_objects_fd where I explain some example use cases of the extensions I’ve implemented for Piglit as part of my work for Igalia. In this example, a Vulkan vertex buffer is created and filled with vertices and then it’s used to render the same chess board pattern once with OpenGL and once with Vulkan.
Continue reading [OpenGL and Vulkan Interoperability on Linux] Part 8: Using a Vulkan vertex buffer from OpenGL and then from Vulkan
This is the 7th post on OpenGL and Vulkan Interoperability with EXT_external_objects. It’s about another EXT_external_objects use case implemented for Piglit as part of my work for Igalia‘s graphics team. In this case a vertex buffer is allocated and filled with data from Vulkan and then it’s used from OpenGL to render a pattern on screen.
Continue reading [OpenGL and Vulkan Interoperability on Linux] Part 7: Reusing a Vulkan vertex buffer from OpenGL
This is another blog post on OpenGL and Vulkan Interoperability. It’s not really a description of a new use case as the Piglit test I am going to describe is quite similar to the previous example we’ve seen where we reused a Vulkan pixel buffer from OpenGL. This Piglit test was written because there’s an interesting issue (Issue 7) in the spec according to which overwriting Vulkan buffers with glBufferSubData is not possible! This is interesting because we can overwrite textures but not buffers. When we attempt to overwrite a buffer using glBufferSubData the driver must return an Invalid Operation Error and this is what we tested with the
vk-pix-buf-update-errors test that can be found in
tests/spec/ext_external_objects directory like all other tests we’ve seen so far.
Continue reading [OpenGL and Vulkan Interoperability on Linux] Part 6: We should be able to reuse a Vulkan pixel buffer from OpenGL but not to overwrite it!
This is the 5th post of the OpenGL and Vulkan interoperability series where I describe some use cases for the EXT_external_objects and EXT_external_objects_fd extensions. These use cases have been implemented inside Piglit as part of my work for Igalia‘s graphics team using a Vulkan framework I’ve written for this purpose.
And in this 5th post, we are going to see a case where a pixel buffer is allocated and filled by Vulkan and its data are used as source data for an OpenGL texture image.
Continue reading [OpenGL and Vulkan Interoperability on Linux] Part 5: A Vulkan pixel buffer is reused by OpenGL