This extension adds support for the FragmentShaderPixelInterlockEXT, FragmentShaderSampleInterlockEXT, and FragmentShaderShadingRateInterlockEXT capabilities from the SPV_EXT_fragment_shader_interlock extension to Vulkan.

Enabling these capabilities provides a critical section for fragment shaders to avoid overlapping pixels being processed at the same time, and certain guarantees about the ordering of fragment shader invocations of fragments of overlapping pixels.

This extension can be useful for algorithms that need to access per-pixel data structures via shader loads and stores. Algorithms using this extension can access per-pixel data structures in critical sections without other invocations accessing the same per-pixel data. Additionally, the ordering guarantees are useful for cases where the API ordering of fragments is meaningful. For example, applications may be able to execute programmable blending operations in the fragment shader, where the destination buffer is read via image loads and the final value is written via image stores.

VK_EXT_fragment_shader_interlock

Name String

VK_EXT_fragment_shader_interlock

Extension Type

Device extension

Registered Extension Number

252

Revision

1

Extension and Version Dependencies

VK_KHR_get_physical_device_properties2 or Version 1.1

Contact

• Piers Daniell pdaniell-nv

Other Extension Metadata

Last Modified Date

2019-05-02

Interactions and External Dependencies

• This extension requires SPV_EXT_fragment_shader_interlock
• This extension provides API support for GL_ARB_fragment_shader_interlock

Contributors

• Daniel Koch, NVIDIA
• Graeme Leese, Broadcom
• Jan-Harald Fredriksen, Arm
• Faith Ekstrand, Intel
• Jeff Bolz, NVIDIA
• Ruihao Zhang, Qualcomm
• Slawomir Grajewski, Intel
• Spencer Fricke, Samsung