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
This is another post of the series where I explain some ideas I tried in order to improve the upscaling of the half-resolution SSAO render target of the VKDF sponza demo that was written by Iago Toral. In the previous post, I had classified the sample neighborhoods in surface neighborhoods and neighborhoods that contain depth discontinuities using the normals. Having this information about the neighborhoods, in this post, I will try to further improve the nearest depth algorithm (see also parts 1 and 2) and reduce the artifacts in the neighborhoods where we detect depth discontinuities.
Continue reading Depth-aware upsampling experiments (Part 4: Improving the nearest depth where we detect discontinuities)
This post is again about improving the upsampling of the half-resolution SSAO render target used in the VKDF sponza demo that was written by Iago Toral. I am going to explain how I used information from the normals to understand if the samples of each 2×2 neighborhood we check during the upsampling belong to the same surface or not, and how this was useful in the upsampling improvement.
Continue reading Depth-aware upsampling experiments (Part 3.2: Improving the upsampling using normals to classify the samples)
In the previous post of these series, I tried to explain the nearest depth algorithm  that I used to improve Iago Toral‘s SSAO upscaling in the sponza demo of VKDF. Although the nearest depth was improving the ambient occlusion in higher resolutions the results were not very good, so I decided to try more quality improvements. In this post, I am going to talk about my first experiments on improving the Z-buffer downsampling.
Continue reading Depth-aware upsampling experiments (Part 2: Improving the Z-buffer downsampling)