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Registered Extension Number

42

Revision

1

Extension and Version Dependencies

Other Extension Metadata

Last Modified Date

2017-03-21

IP Status

No known IP claims.

Interactions and External Dependencies
Contributors
  • Dominik Witczak, AMD

  • Daniel Rakos, AMD

  • Graham Sellers, AMD

  • Matthaeus G. Chajdas, AMD

  • Qun Lin, AMD

  • Rex Xu, AMD

  • Timothy Lottes, AMD

Description

This extension adds two related features.

Firstly, support for the following SPIR-V extension in Vulkan is added:

  • SPV_AMD_texture_gather_bias_lod

Secondly, the extension allows the application to query which formats can be used together with the new function prototypes introduced by the SPIR-V extension.

New Enum Constants

  • VK_AMD_TEXTURE_GATHER_BIAS_LOD_EXTENSION_NAME

  • VK_AMD_TEXTURE_GATHER_BIAS_LOD_SPEC_VERSION

  • Extending VkStructureType:

    • VK_STRUCTURE_TYPE_TEXTURE_LOD_GATHER_FORMAT_PROPERTIES_AMD

New SPIR-V Capabilities

Examples

struct VkTextureLODGatherFormatPropertiesAMD
{
    VkStructureType sType;
    const void*     pNext;
    VkBool32        supportsTextureGatherLODBiasAMD;
};

// ----------------------------------------------------------------------------------------
// How to detect if an image format can be used with the new function prototypes.
VkPhysicalDeviceImageFormatInfo2   formatInfo;
VkImageFormatProperties2           formatProps;
VkTextureLODGatherFormatPropertiesAMD textureLODGatherSupport;

textureLODGatherSupport.sType = VK_STRUCTURE_TYPE_TEXTURE_LOD_GATHER_FORMAT_PROPERTIES_AMD;
textureLODGatherSupport.pNext = nullptr;

formatInfo.sType  = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_IMAGE_FORMAT_INFO_2;
formatInfo.pNext  = nullptr;
formatInfo.format = ...;
formatInfo.type   = ...;
formatInfo.tiling = ...;
formatInfo.usage  = ...;
formatInfo.flags  = ...;

formatProps.sType = VK_STRUCTURE_TYPE_IMAGE_FORMAT_PROPERTIES_2;
formatProps.pNext = &textureLODGatherSupport;

vkGetPhysicalDeviceImageFormatProperties2(physical_device, &formatInfo, &formatProps);

if (textureLODGatherSupport.supportsTextureGatherLODBiasAMD == VK_TRUE)
{
    // physical device supports SPV_AMD_texture_gather_bias_lod for the specified
    // format configuration.
}
else
{
    // physical device does not support SPV_AMD_texture_gather_bias_lod for the
    // specified format configuration.
}

Version History

  • Revision 1, 2017-03-21 (Dominik Witczak)

    • Initial draft

See Also

Document Notes

For more information, see the Vulkan Specification

This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.

Copyright (c) 2014-2020 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.