C Specification

If the pNext chain of VkPipelineMultisampleStateCreateInfo includes a VkPipelineCoverageToColorStateCreateInfoNV structure, then that structure controls whether the fragment coverage is substituted for a fragment color output and, if so, which output is replaced.

The VkPipelineCoverageToColorStateCreateInfoNV structure is defined as:

typedef struct VkPipelineCoverageToColorStateCreateInfoNV {
    VkStructureType                                sType;
    const void*                                    pNext;
    VkPipelineCoverageToColorStateCreateFlagsNV    flags;
    VkBool32                                       coverageToColorEnable;
    uint32_t                                       coverageToColorLocation;
} VkPipelineCoverageToColorStateCreateInfoNV;

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.

  • coverageToColorEnable controls whether the fragment coverage value replaces a fragment color output.

  • coverageToColorLocation controls which fragment shader color output value is replaced.

Description

If coverageToColorEnable is VK_TRUE, the fragment coverage information is treated as a bitmask with one bit for each sample (as in the Sample Mask section), and this bitmask replaces the first component of the color value corresponding to the fragment shader output location with Location equal to coverageToColorLocation and Index equal to zero. If the color attachment format has fewer bits than the sample coverage, the low bits of the sample coverage bitmask are taken without any clamping. If the color attachment format has more bits than the sample coverage, the high bits of the sample coverage bitmask are filled with zeros.

If Sample Shading is in use, the coverage bitmask only has bits set for samples that correspond to the fragment shader invocation that shades those samples.

This pipeline stage occurs after sample counting and before blending, and is always performed after fragment shading regardless of the setting of EarlyFragmentTests.

If coverageToColorEnable is VK_FALSE, these operations are skipped. If this structure is not present, it is as if coverageToColorEnable is VK_FALSE.

Valid Usage
  • If coverageToColorEnable is VK_TRUE, then the render pass subpass indicated by VkGraphicsPipelineCreateInfo::renderPass and VkGraphicsPipelineCreateInfo::subpass must have a color attachment at the location selected by coverageToColorLocation, with a VkFormat of VK_FORMAT_R8_UINT, VK_FORMAT_R8_SINT, VK_FORMAT_R16_UINT, VK_FORMAT_R16_SINT, VK_FORMAT_R32_UINT, or VK_FORMAT_R32_SINT

Valid Usage (Implicit)
  • sType must be VK_STRUCTURE_TYPE_PIPELINE_COVERAGE_TO_COLOR_STATE_CREATE_INFO_NV

  • flags must be 0

See Also

Document Notes

For more information, see the Vulkan Specification at URL

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

Copyright (c) 2014-2019 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.