This extension adds support for the ShaderViewportIndexLayerEXT capability from the SPV_EXT_shader_viewport_index_layer extension in Vulkan.

This extension allows variables decorated with the Layer and ViewportIndex built-ins to be exported from vertex or tessellation shaders, using the ShaderViewportIndexLayerEXT capability.

When using GLSL source-based shading languages, the gl_ViewportIndex and gl_Layer built-in variables map to the SPIR-V ViewportIndex and Layer built-in decorations, respectively. Behaviour of these variables is extended as described in the GL_ARB_shader_viewport_layer_array (or the precursor GL_AMD_vertex_shader_layer, GL_AMD_vertex_shader_viewport_index, and GL_NV_viewport_array2 extensions).

Promotion to Vulkan 1.2

All functionality in this extension is included in core Vulkan 1.2.

The single ShaderViewportIndexLayerEXT capability from the SPV_EXT_shader_viewport_index_layer extension is replaced by the ShaderViewportIndex and ShaderLayer capabilities from SPIR-V 1.5 which are enabled by the shaderOutputViewportIndex and shaderOutputLayer features, respectively. Additionally, if Vulkan 1.2 is supported but this extension is not, these capabilities are optional.

Enabling both features is equivalent to enabling the VK_EXT_shader_viewport_index_layer extension.

VK_EXT_shader_viewport_index_layer

Name String

VK_EXT_shader_viewport_index_layer

Extension Type

Device extension

Registered Extension Number

163

Revision

1

Deprecation state

• Promoted to Vulkan 1.2

Contact

• Daniel Koch dgkoch

Other Extension Metadata

Last Modified Date

2017-08-08

Interactions and External Dependencies

• Promoted to Vulkan 1.2 Core
• This extension requires SPV_EXT_shader_viewport_index_layer
• This extension provides API support for GL_ARB_shader_viewport_layer_array, GL_AMD_vertex_shader_layer, GL_AMD_vertex_shader_viewport_index, and GL_NV_viewport_array2
• This extension requires the multiViewport feature.
• This extension interacts with the tessellationShader feature.

Contributors

• Piers Daniell, NVIDIA
• Jeff Bolz, NVIDIA
• Jan-Harald Fredriksen, ARM
• Daniel Rakos, AMD
• Slawomir Grajeswki, Intel