This extension adds support for the following SPIR-V extension in Vulkan:

• SPV_NV_fragment_shader_barycentric

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

• PerVertexNV, 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
• BaryCoordNV, which indicates that the variable is a three-component floating-point vector holding barycentric weights for the fragment produced using perspective interpolation
• BaryCoordNoPerspNV, 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_NV_fragment_shader_barycentric maps to these SPIR-V built-in decorations:

• in vec3 gl_BaryCoordNV; → BaryCoordNV
• in vec3 gl_BaryCoordNoPerspNV; → BaryCoordNoPerspNV

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

Promotion to VK_KHR_fragment_shader_barycentric

All functionality in this extension is included in VK_KHR_fragment_shader_barycentric, with the suffix changed to KHR.

VK_NV_fragment_shader_barycentric

Name String

VK_NV_fragment_shader_barycentric

Extension Type

Device extension

Registered Extension Number

204

Revision

1

Extension and Version Dependencies

VK_KHR_get_physical_device_properties2

Deprecation state

• Promoted to VK_KHR_fragment_shader_barycentric extension

Contact

• Pat Brown nvpbrown

Other Extension Metadata

Last Modified Date

2018-08-03

IP Status

No known IP claims.

Interactions and External Dependencies

• This extension requires SPV_NV_fragment_shader_barycentric
• This extension provides API support for GL_NV_fragment_shader_barycentric

Contributors

• Pat Brown, NVIDIA
• Daniel Koch, NVIDIA