434fabe221
The multiViewport feature isn't required for GL 4.3, it's required for GL 4.1. Technically speaking, we could have just dropped it because we already list the maxViewports requirement. But it seems better to be very clear here to me. Fixes:29f8f21bff("docs: document zink GL 4.3 requirements") Acked-by: Mike Blumenkrantz <michael.blumenkrantz@gmail.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15300> (cherry picked from commite666134975)
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8.4 KiB
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304 lines
8.4 KiB
ReStructuredText
Zink
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====
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Overview
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--------
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The Zink driver is a Gallium driver that emits Vulkan API calls instead
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of targeting a specific GPU architecture. This can be used to get full
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desktop OpenGL support on devices that only support Vulkan.
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Features
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--------
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The feature-level of Zink depends on two things; what's implemented in Zink,
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as well as the features of the Vulkan driver.
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OpenGL 2.1
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^^^^^^^^^^
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OpenGL 2.1 is the minimum version Zink can support, and will always be
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exposed, given Vulkan support. There's a few features that are required
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for correct behavior, but not all of these are validated; instead you'll
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see rendering-issues and likely validation error, or even crashes.
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Here's a list of those requirements:
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* Vulkan 1.0
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* ``VkPhysicalDeviceFeatures``:
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* ``logicOp``
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* ``fillModeNonSolid``
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* ``wideLines``
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* ``largePoints``
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* ``alphaToOne``
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* ``shaderClipDistance``
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* Device extensions:
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* `VK_KHR_maintenance1`_
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* `VK_EXT_custom_border_color`_
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* `VK_EXT_provoking_vertex`_
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* `VK_EXT_line_rasterization`_, with the following ``VkPhysicalDeviceLineRasterizationFeaturesEXT``:
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* ``rectangularLines``
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* ``bresenhamLines``
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* ``smoothLines``
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* ``stippledRectangularLines``
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* ``stippledBresenhamLines``
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* ``stippledSmoothLines``
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In addition to this, `VK_KHR_external_memory`_ is required to support the
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DRI code-path.
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We also require either the `VK_EXT_scalar_block_layout`_ extension or
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Vulkan 1.2, with the ``scalarBlockLayout`` feature.
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OpenGL 3.0
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^^^^^^^^^^
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For OpenGL 3.0 support, the following additional requirements needs to be
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supported:
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* ``VkPhysicalDeviceFeatures``:
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* ``independentBlend``
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* Device extensions:
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* `VK_EXT_transform_feedback`_
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* `VK_EXT_conditional_rendering`_
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OpenGL 3.1
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^^^^^^^^^^
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For OpenGL 3.1 support, the following additional ``VkPhysicalDeviceLimits``
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are required:
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* ``maxPerStageDescriptorSamplers`` ≥ 16
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OpenGL 3.2
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^^^^^^^^^^
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For OpenGL 3.2 support, the following additional ``VkPhysicalDeviceFeatures``
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are required to be supported, although some of these might not actually get
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verified:
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* ``depthClamp``
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* ``geometryShader``
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* ``shaderTessellationAndGeometryPointSize``
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OpenGL 3.3
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^^^^^^^^^^
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For OpenGL 3.3 support, the following additional requirements needs to be
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supported, although some of these might not actually get verified:
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* ``VkPhysicalDeviceFeatures``:
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* ``occlusionQueryPrecise``
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* Device extensions:
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* `VK_EXT_vertex_attribute_divisor`_
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OpenGL 4.0
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^^^^^^^^^^
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For OpenGL 4.0 support, the following additional requirements needs to be
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supported:
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* ``VkPhysicalDeviceFeatures``:
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* ``sampleRateShading``
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* ``tessellationShader``
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* ``imageCubeArray``
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* Device extensions:
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* `VK_KHR_maintenance2`_
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* Formats requiring ``VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT``:
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* ``VK_FORMAT_R32G32B32_SFLOAT``
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* ``VK_FORMAT_R32G32B32_SINT``
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* ``VK_FORMAT_R32G32B32_UINT``
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OpenGL 4.1
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^^^^^^^^^^
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For OpenGL 4.1 support, the following additional requirements needs to be
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supported:
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* ``VkPhysicalDeviceFeatures``:
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* ``multiViewport``
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* ``VkPhysicalDeviceLimits``
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* ``maxImageDimension2D`` ≥ 16384
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* ``maxViewports`` ≥ 16
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OpenGL 4.2
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^^^^^^^^^^
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For OpenGL 4.2 support, the following additional requirements needs to be
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supported:
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* ``VkPhysicalDeviceLimits``:
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* ``shaderStorageImageExtendedFormats``
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* ``shaderStorageImageWriteWithoutFormat``
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* For Vulkan 1.2 and above:
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* ``VkPhysicalDeviceVulkan11Features``:
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* ``shaderDrawParameters``
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* ``vertexPipelineStoresAndAtomics``
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* ``fragmentStoresAndAtomics``
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* ``textureCompressionBC``
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* For Vulkan 1.1 and below:
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* Device extensions:
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* `VK_KHR_shader_draw_parameters`_
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* Formats requiring ``VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT``:
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* ``VK_FORMAT_BC7_UNORM_BLOCK``
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* ``VK_FORMAT_BC7_SRGB_BLOCK``
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* ``VK_FORMAT_BC6H_SFLOAT_BLOCK``
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* ``VK_FORMAT_BC6H_UFLOAT_BLOCK``
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OpenGL 4.3
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^^^^^^^^^^
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For OpenGL 4.3 support, the following additional requirements needs to be
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supported:
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* ``VkPhysicalDeviceFeatures``:
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* ``robustBufferAccess``
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* Formats requiring ``VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT``:
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* ``VK_FORMAT_R8G8B8A8_UNORM``
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* ``VK_FORMAT_R8G8B8A8_SRGB``
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* ``VK_FORMAT_R16_UNORM``
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* ``VK_FORMAT_R16G16_UNORM``
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* ``VK_FORMAT_R16_SNORM``
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* ``VK_FORMAT_R16G16_SNORM``
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* ``VK_FORMAT_D32_SFLOAT_S8_UINT``
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OpenGL 4.4
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^^^^^^^^^^
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For OpenGL 4.4 support, the following additional requirements needs to be
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supported:
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* Formats requiring ``VK_FORMAT_FEATURE_VERTEX_BUFFER_BIT``:
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* ``VK_FORMAT_B10G11R11_UFLOAT_PACK32``
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* Device extensions:
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* `VK_KHR_sampler_mirror_clamp_to_edge`_
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OpenGL 4.5
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^^^^^^^^^^
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For OpenGL 4.5 support, the following additional ``VkPhysicalDeviceFeatures``
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are required to be supported
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* ``shaderCullDistance``
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OpenGL 4.6
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^^^^^^^^^^
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For OpenGL 4.6 support, the following additional ``VkPhysicalDeviceFeatures``
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are required to be supported
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* ``VkPhysicalDeviceFeatures``:
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* ``samplerAnisotropy``
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* ``pipelineStatisticsQuery``
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* ``depthBiasClamp``
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* Device extensions:
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* `VK_KHR_draw_indirect_count`_
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Performance
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-----------
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If you notice poor performance and high CPU usage while running an application,
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changing the descriptor manager may improve performance:
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.. envvar:: ZINK_DESCRIPTORS <mode> ("auto")
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``auto``
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Automatically detect best mode. This is the default.
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``lazy``
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Disable caching and attempt to use the least amount of CPU.
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``nofallback``
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Always use caching to try reducing GPU churn.
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``notemplates``
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The same as `auto`, but disables the use of `VK_KHR_descriptor_templates`.
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Debugging
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---------
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There's a few tools that are useful for debugging Zink, like this environment
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variable:
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.. envvar:: ZINK_DEBUG <flags> ("")
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``nir``
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Print the NIR form of all shaders to stderr.
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``spirv``
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Write the binary SPIR-V form of all compiled shaders to a file in the
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current directory, and print a message with the filename to stderr.
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``tgsi``
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Print the TGSI form of TGSI shaders to stderr.
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``validation``
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Dump Validation layer output.
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Vulkan Validation Layers
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^^^^^^^^^^^^^^^^^^^^^^^^
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Another useful tool for debugging is the `Vulkan Validation Layers
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<https://github.com/KhronosGroup/Vulkan-ValidationLayers/blob/master/README.md>`_.
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The validation layers effectively insert extra checking between Zink and the
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Vulkan driver, pointing out incorrect usage of the Vulkan API. The layers can
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be enabled by setting the environment variable :envvar:`VK_INSTANCE_LAYERS` to
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"VK_LAYER_KHRONOS_validation". You can read more about the Validation Layers
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in the link above.
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IRC
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---
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In order to make things a bit easier to follow, we have decided to create our
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own IRC channel. If you're interested in contributing, or have any technical
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questions, don't hesitate to visit `#zink on OFTC
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<irc://irc.oftc.net/zink>`__ and say hi!
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.. _VK_KHR_maintenance1: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_KHR_maintenance1.html
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.. _VK_KHR_external_memory: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_KHR_external_memory.html
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.. _VK_EXT_scalar_block_layout: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_EXT_scalar_block_layout.html
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.. _VK_EXT_transform_feedback: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_EXT_transform_feedback.html
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.. _VK_EXT_conditional_rendering: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_EXT_conditional_rendering.html
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.. _VK_EXT_vertex_attribute_divisor: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_EXT_vertex_attribute_divisor.html
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.. _VK_KHR_maintenance2: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_KHR_maintenance2.html
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.. _VK_KHR_shader_draw_parameters: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_KHR_shader_draw_parameters.html
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.. _VK_KHR_draw_indirect_count: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_KHR_draw_indirect_count.html
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.. _VK_KHR_sampler_mirror_clamp_to_edge: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_KHR_sampler_mirror_clamp_to_edge.html
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.. _VK_EXT_custom_border_color: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_EXT_custom_border_color.html
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.. _VK_EXT_provoking_vertex: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_EXT_provoking_vertex.html
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.. _VK_EXT_line_rasterization: https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_EXT_line_rasterization.html
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