# VkPipelineCoverageReductionStateCreateInfoNV(3) Manual Page

## Name

VkPipelineCoverageReductionStateCreateInfoNV - Structure specifying parameters controlling coverage reduction

## C Specification

If the pipeline’s VkPipelineMultisampleStateCreateInfo::`rasterizationSamples` is greater than the VkAttachmentDescription::`samples` of the color attachments in the subpass, then the fragment’s coverage is reduced from `rasterizationSamples` bits to a color sample mask with VkAttachmentDescription::`samples` bits.

When the `VK_NV_coverage_reduction_mode` extension is enabled, the pipeline state controlling coverage reduction is specified through the members of the `VkPipelineCoverageReductionStateCreateInfoNV` structure.

The `VkPipelineCoverageReductionStateCreateInfoNV` structure is defined as:

    typedef struct VkPipelineCoverageReductionStateCreateInfoNV {
        VkStructureType                                  sType;
        const void*                                      pNext;
        VkPipelineCoverageReductionStateCreateFlagsNV    flags;
        VkCoverageReductionModeNV                        coverageReductionMode;
    } VkPipelineCoverageReductionStateCreateInfoNV;

## Members

- `sType` is the type of this structure.

- `pNext` is `NULL` or a pointer to an extension-specific structure.

- `flags` is reserved for future use.

- `coverageReductionMode` is a VkCoverageReductionModeNV value controlling how the color sample mask is generated from the coverage mask.

## Description

If this structure is not present, the default coverage reduction mode is inferred as follows:

- If the `VK_NV_framebuffer_mixed_samples` extension is enabled, then it is as if the `coverageReductionMode` is `VK_COVERAGE_REDUCTION_MODE_MERGE_NV`.

- If the `VK_AMD_mixed_attachment_samples` extension is enabled, then it is as if the `coverageReductionMode` is `VK_COVERAGE_REDUCTION_MODE_TRUNCATE_NV`.

- If both `VK_NV_framebuffer_mixed_samples` and `VK_AMD_mixed_attachment_samples` are enabled, then the default coverage reduction mode is implementation-dependent.

Valid Usage (Implicit)

- `sType` must be `VK_STRUCTURE_TYPE_PIPELINE_COVERAGE_REDUCTION_STATE_CREATE_INFO_NV`

- `flags` must be `0`

- `coverageReductionMode` must be a valid VkCoverageReductionModeNV value

## See Also

VkCoverageReductionModeNV, VkPipelineCoverageReductionStateCreateFlagsNV, VkStructureType

## Document Notes

For more information, see the Vulkan Specification

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

## Copyright

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