1  include::meta/VK_NV_sample_mask_override_coverage.txt[]
 2  
 3  *Last Modified Date*::
 4      2016-12-08
 5  *IP Status*::
 6      No known IP claims.
 7  *Interactions and External Dependencies*::
 8    - This extension requires the
 9      https://www.khronos.org/registry/spir-v/extensions/NV/SPV_NV_sample_mask_override_coverage.html[`SPV_NV_sample_mask_override_coverage`]
10      SPIR-V extension.
11    - This extension requires the
12      https://www.khronos.org/registry/OpenGL/extensions/NV/NV_sample_mask_override_coverage.txt[`GL_NV_sample_mask_override_coverage`]
13      extension for GLSL source languages.
14  *Contributors*::
15    - Daniel Koch, NVIDIA
16    - Jeff Bolz, NVIDIA
17  
18  This extension adds support for the following SPIR-V extension in Vulkan:
19  
20    * `SPV_NV_sample_mask_override_coverage`
21  
22  The extension provides access to the code:OverrideCoverageNV decoration
23  under the code:SampleMaskOverrideCoverageNV capability.
24  Adding this decoration to a variable with the code:SampleMask builtin
25  decoration allows the shader to modify the coverage mask and affect which
26  samples are used to process the fragment.
27  
28  When using GLSL source-based shader languages, the code:override_coverage
29  layout qualifier from `GL_NV_sample_mask_override_coverage` maps to the
30  code:OverrideCoverageNV decoration.
31  To use the code:override_coverage layout qualifier in GLSL the
32  `GL_NV_sample_mask_override_coverage` extension must be enabled.
33  Behavior is described in the `GL_NV_sample_mask_override_coverage` extension
34  spec.
35  
36  === New Object Types
37  
38  None.
39  
40  === New Enum Constants
41  
42  None.
43  
44  === New Enums
45  
46  None.
47  
48  === New Structures
49  
50  None.
51  
52  === New Functions
53  
54  None.
55  
56  === New Built-In Variables
57  
58  None.
59  
60  === New Variable Decoration
61  
62    * <<interfaces-builtin-variables-samplemask,OverrideCoverageNV in
63      SampleMask>>
64  
65  === New SPIR-V Capabilities
66  
67    * <<spirvenv-capabilities-table-samplemaskoverridecoverage,SampleMaskOverrideCoverageNV>>
68  
69  === Issues
70  
71  None.
72  
73  === Version History
74  
75    * Revision 1, 2016-12-08 (Piers Daniell)
76      - Internal revisions