[OpenGL and Vulkan Interoperability on Linux] Part 11: Debugging the semaphore synchronization 🍄

One important part of the implementation of the EXT_external_objects and EXT_external_objects_fd groups of extensions for iris (the Intel gallium OpenGL driver) was the semaphore synchronization (EXT_semaphore extension). We’ve seen how the GL semaphores structs and functions that are introduced by this extension should be used in previous interoperability posts. In this post, I’ll try to describe the methods we’ve used to debug the EXT_semaphore implementation itself as well as the fences backend of the iris driver without getting into many driver internals details.

Continue reading [OpenGL and Vulkan Interoperability on Linux] Part 11: Debugging the semaphore synchronization 🍄

EXT_external_objects and EXT_external_objects_fd for the Intel iris driver have been merged into mesa3D! [updated]

This post is a quick status update on OpenGL and Vulkan Interoperability extensions for Linux mesa3D drivers:

Both EXT_external_objects and EXT_external_objects_fd implementations for the Intel iris driver have been finally merged into mesa3D earlier today and will be available in next release! 🎉

Continue reading EXT_external_objects and EXT_external_objects_fd for the Intel iris driver have been merged into mesa3D! [updated]

About VK_EXT_sample_locations

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.

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FOSSCOMM 2020, and a status update on EXT_external_objects(_fd) extensions [en, gr]

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.

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A hack to display the Vulkan CTS tests output

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.

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[OpenGL and Vulkan Interoperability on Linux] Part 10: Reusing a Vulkan stencil buffer from OpenGL

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.

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[OpenGL and Vulkan Interoperability on Linux] Part 9: Reusing a Vulkan z 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

[OpenGL and Vulkan Interoperability on Linux] Part 8: Using a Vulkan vertex buffer from OpenGL and then from Vulkan

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

[OpenGL and Vulkan Interoperability on Linux] Part 7: Reusing a Vulkan vertex buffer from OpenGL

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

[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 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!