Registered Extension Number

323

Revision

1

Extension and Version Dependencies

Contact

  • Stu Smith

Extension Proposal

Other Extension Metadata

Last Modified Date

2022-03-10

IP Status

No known IP claims.

Interactions and External Dependencies
Contributors
  • Stu Smith, AMD

  • Tobias Hector, AMD

  • Graeme Leese, Broadcom

  • Jan-Harald Fredriksen, Arm

  • Slawek Grajewski, Intel

  • Pat Brown, NVIDIA

  • Hans-Kristian Arntzen, Valve

  • Contributors to the VK_NV_fragment_shader_barycentric specification

Description

This extension is based on the VK_NV_fragment_shader_barycentric extension, and adds support for the following SPIR-V extension in Vulkan:

The extension provides access to three additional fragment shader variable decorations in SPIR-V:

  • PerVertexKHR, which indicates that a fragment shader input will not have interpolated values, but instead must be accessed with an extra array index that identifies one of the vertices of the primitive producing the fragment

  • BaryCoordKHR, which indicates that the variable is a three-component floating-point vector holding barycentric weights for the fragment produced using perspective interpolation

  • BaryCoordNoPerspKHR, which indicates that the variable is a three-component floating-point vector holding barycentric weights for the fragment produced using linear interpolation

When using GLSL source-based shader languages, the following variables from GL_EXT_fragment_shader_barycentric map to these SPIR-V built-in decorations:

  • in vec3 gl_BaryCoordEXT;BaryCoordKHR

  • in vec3 gl_BaryCoordNoPerspEXT;BaryCoordNoPerspKHR

GLSL variables declared using the pervertexEXT GLSL qualifier are expected to be decorated with PerVertexKHR in SPIR-V.

New Structures

New Enum Constants

  • VK_KHR_FRAGMENT_SHADER_BARYCENTRIC_EXTENSION_NAME

  • VK_KHR_FRAGMENT_SHADER_BARYCENTRIC_SPEC_VERSION

  • Extending VkStructureType:

    • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FRAGMENT_SHADER_BARYCENTRIC_FEATURES_KHR

    • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FRAGMENT_SHADER_BARYCENTRIC_PROPERTIES_KHR

New Built-In Variables

New SPIR-V Decorations

New SPIR-V Capabilities

Issues

Version History

  • Revision 1, 2022-03-10 (Stu Smith)

    • Initial revision

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 2014-2022 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0