| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Vulkan.Extensions.VK_NV_framebuffer_mixed_samples
Description
Name
VK_NV_framebuffer_mixed_samples - device extension
VK_NV_framebuffer_mixed_samples
- Name String
VK_NV_framebuffer_mixed_samples
- Extension Type
- Device extension
- Registered Extension Number
- 153
- Revision
- 1
- Extension and Version Dependencies
- Requires Vulkan 1.0
- Contact
Other Extension Metadata
- Last Modified Date
- 2017-06-04
- Contributors
- Jeff Bolz, NVIDIA
Description
This extension allows multisample rendering with a raster and depth/stencil sample count that is larger than the color sample count. Rasterization and the results of the depth and stencil tests together determine the portion of a pixel that is “covered”. It can be useful to evaluate coverage at a higher frequency than color samples are stored. This coverage is then “reduced” to a collection of covered color samples, each having an opacity value corresponding to the fraction of the color sample covered. The opacity can optionally be blended into individual color samples.
Rendering with fewer color samples than depth/stencil samples greatly reduces the amount of memory and bandwidth consumed by the color buffer. However, converting the coverage values into opacity introduces artifacts where triangles share edges and may not be suitable for normal triangle mesh rendering.
One expected use case for this functionality is Stencil-then-Cover path rendering (similar to the OpenGL GL_NV_path_rendering extension). The stencil step determines the coverage (in the stencil buffer) for an entire path at the higher sample frequency, and then the cover step draws the path into the lower frequency color buffer using the coverage information to antialias path edges. With this two-step process, internal edges are fully covered when antialiasing is applied and there is no corruption on these edges.
The key features of this extension are:
- It allows render pass and framebuffer objects to be created where the number of samples in the depth/stencil attachment in a subpass is a multiple of the number of samples in the color attachments in the subpass.
- A coverage reduction step is added to Fragment Operations which converts a set of covered raster/depth/stencil samples to a set of color samples that perform blending and color writes. The coverage reduction step also includes an optional coverage modulation step, multiplying color values by a fractional opacity corresponding to the number of associated raster/depth/stencil samples covered.
New Structures
New Enums
New Bitmasks
New Enum Constants
Version History
Revision 1, 2017-06-04 (Jeff Bolz)
- Internal revisions
See Also
CoverageModulationModeNV,
PipelineCoverageModulationStateCreateFlagsNV,
PipelineCoverageModulationStateCreateInfoNV
Document Notes
For more information, see the Vulkan Specification
This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.
Synopsis
- data PipelineCoverageModulationStateCreateInfoNV = PipelineCoverageModulationStateCreateInfoNV {}
- newtype PipelineCoverageModulationStateCreateFlagsNV = PipelineCoverageModulationStateCreateFlagsNV Flags
- newtype CoverageModulationModeNV where
- CoverageModulationModeNV Int32
- pattern COVERAGE_MODULATION_MODE_NONE_NV :: CoverageModulationModeNV
- pattern COVERAGE_MODULATION_MODE_RGB_NV :: CoverageModulationModeNV
- pattern COVERAGE_MODULATION_MODE_ALPHA_NV :: CoverageModulationModeNV
- pattern COVERAGE_MODULATION_MODE_RGBA_NV :: CoverageModulationModeNV
- type NV_FRAMEBUFFER_MIXED_SAMPLES_SPEC_VERSION = 1
- pattern NV_FRAMEBUFFER_MIXED_SAMPLES_SPEC_VERSION :: forall a. Integral a => a
- type NV_FRAMEBUFFER_MIXED_SAMPLES_EXTENSION_NAME = "VK_NV_framebuffer_mixed_samples"
- pattern NV_FRAMEBUFFER_MIXED_SAMPLES_EXTENSION_NAME :: forall a. (Eq a, IsString a) => a
Documentation
data PipelineCoverageModulationStateCreateInfoNV Source #
VkPipelineCoverageModulationStateCreateInfoNV - Structure specifying parameters controlling coverage modulation
Description
If coverageModulationTableEnable is
FALSE, then for each color sample the
associated bits of the pixel coverage are counted and divided by the
number of associated bits to produce a modulation factor R in the range
(0,1] (a value of zero would have been killed due to a color coverage of
0). Specifically:
- N = value of
rasterizationSamples - M = value of
AttachmentDescription::samplesfor any color attachments - R = popcount(associated coverage bits) / (N / M)
If coverageModulationTableEnable is
TRUE, the value R is computed using a
programmable lookup table. The lookup table has N / M elements, and the
element of the table is selected by:
- R =
pCoverageModulationTable[popcount(associated coverage bits)-1]
Note that the table does not have an entry for popcount(associated coverage bits) = 0, because such samples would have been killed.
The values of pCoverageModulationTable may be rounded to an
implementation-dependent precision, which is at least as fine as 1 / N,
and clamped to [0,1].
For each color attachment with a floating point or normalized color
format, each fragment output color value is replicated to M values which
can each be modulated (multiplied) by that color sample’s associated
value of R. Which components are modulated is controlled by
coverageModulationMode.
If this structure is not present, it is as if coverageModulationMode
is COVERAGE_MODULATION_MODE_NONE_NV.
If the
coverage reduction mode
is
COVERAGE_REDUCTION_MODE_TRUNCATE_NV,
each color sample is associated with only a single coverage sample. In
this case, it is as if coverageModulationMode is
COVERAGE_MODULATION_MODE_NONE_NV.
Valid Usage
-
If
coverageModulationTableEnableisTRUE,coverageModulationTableCountmust be equal to the number of rasterization samples divided by the number of color samples in the subpass
Valid Usage (Implicit)
-
flagsmust be0 -
coverageModulationModemust be a validCoverageModulationModeNVvalue
See Also
Bool32, CoverageModulationModeNV,
PipelineCoverageModulationStateCreateFlagsNV,
StructureType
Constructors
| PipelineCoverageModulationStateCreateInfoNV | |
Fields
| |
Instances
newtype PipelineCoverageModulationStateCreateFlagsNV Source #
VkPipelineCoverageModulationStateCreateFlagsNV - Reserved for future use
Description
PipelineCoverageModulationStateCreateFlagsNV is a bitmask type for
setting a mask, but is currently reserved for future use.
See Also
Constructors
| PipelineCoverageModulationStateCreateFlagsNV Flags |
Instances
newtype CoverageModulationModeNV Source #
VkCoverageModulationModeNV - Specify the coverage modulation mode
See Also
Constructors
| CoverageModulationModeNV Int32 |
Bundled Patterns
| pattern COVERAGE_MODULATION_MODE_NONE_NV :: CoverageModulationModeNV |
|
| pattern COVERAGE_MODULATION_MODE_RGB_NV :: CoverageModulationModeNV |
|
| pattern COVERAGE_MODULATION_MODE_ALPHA_NV :: CoverageModulationModeNV |
|
| pattern COVERAGE_MODULATION_MODE_RGBA_NV :: CoverageModulationModeNV |
|
Instances
pattern NV_FRAMEBUFFER_MIXED_SAMPLES_SPEC_VERSION :: forall a. Integral a => a Source #
type NV_FRAMEBUFFER_MIXED_SAMPLES_EXTENSION_NAME = "VK_NV_framebuffer_mixed_samples" Source #
pattern NV_FRAMEBUFFER_MIXED_SAMPLES_EXTENSION_NAME :: forall a. (Eq a, IsString a) => a Source #