Vulkan.Extensions.VK_NV_corner_sampled_image

Name

VK_NV_corner_sampled_image - device extension

VK_NV_corner_sampled_image

Name String

VK_NV_corner_sampled_image

Extension Type

Device extension

Registered Extension Number

51

Revision

2

Extension and Version Dependencies

• Requires Vulkan 1.0
• Requires VK_KHR_get_physical_device_properties2

Contact

• Daniel Koch @dgkoch%0A<<Here describe the issue or question you have about the VK_NV_corner_sampled_image extension> >

Other Extension Metadata

Last Modified Date

2018-08-13

Contributors

• Jeff Bolz, NVIDIA
• Pat Brown, NVIDIA
• Chris Lentini, NVIDIA

Description

This extension adds support for a new image organization, which this extension refers to as “corner-sampled” images. A corner-sampled image differs from a conventional image in the following ways:

• Texels are centered on integer coordinates. See Unnormalized Texel Coordinate Operations
• Normalized coordinates are scaled using coord × (dim - 1) rather than coord × dim, where dim is the size of one dimension of the image. See normalized texel coordinate transform.
• Partial derivatives are scaled using coord × (dim - 1) rather than coord × dim. See Scale Factor Operation.
• Calculation of the next higher lod size goes according to ⌈dim / 2⌉ rather than ⌊dim / 2⌋. See Image Miplevel Sizing.
• The minimum level size is 2x2 for 2D images and 2x2x2 for 3D images. See Image Miplevel Sizing.

This image organization is designed to facilitate a system like Ptex with separate textures for each face of a subdivision or polygon mesh. Placing sample locations at pixel corners allows applications to maintain continuity between adjacent patches by duplicating values along shared edges. Additionally, using the modified mipmapping logic along with texture dimensions of the form 2n+1 allows continuity across shared edges even if the adjacent patches use different level-of-detail values.

New Structures

• Extending PhysicalDeviceFeatures2, DeviceCreateInfo:

  • PhysicalDeviceCornerSampledImageFeaturesNV

New Enum Constants

• NV_CORNER_SAMPLED_IMAGE_EXTENSION_NAME

• NV_CORNER_SAMPLED_IMAGE_SPEC_VERSION

• Extending ImageCreateFlagBits:

  • IMAGE_CREATE_CORNER_SAMPLED_BIT_NV

• Extending StructureType:

  • STRUCTURE_TYPE_PHYSICAL_DEVICE_CORNER_SAMPLED_IMAGE_FEATURES_NV

Issues

1. What should this extension be named?

   DISCUSSION: While naming this extension, we chose the most distinctive aspect of the image organization and referred to such images as “corner-sampled images”. As a result, we decided to name the extension NV_corner_sampled_image.

1. Do we need a format feature flag so formats can advertise if they support corner-sampling?

   DISCUSSION: Currently NVIDIA supports this for all 2D and 3D formats, but not for cube maps or depth-stencil formats. A format feature might be useful if other vendors would only support this on some formats.

2. Do integer texel coordinates have a different range for corner-sampled images?

   RESOLVED: No, these are unchanged.

3. Do unnormalized sampler coordinates work with corner-sampled images? Are there any functional differences?

   RESOLVED: Yes. Unnormalized coordinates are treated as already scaled for corner-sample usage.

4. Should we have a diagram in the “Image Operations” chapter demonstrating different texel sampling locations?

   UNRESOLVED: Probaby, but later.

Version History

• Revision 1, 2018-08-14 (Daniel Koch)

  • Internal revisions

• Revision 2, 2018-08-14 (Daniel Koch)

  • ???

See Also

PhysicalDeviceCornerSampledImageFeaturesNV

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.

Documentation

data PhysicalDeviceCornerSampledImageFeaturesNV

VkPhysicalDeviceCornerSampledImageFeaturesNV - Structure describing corner sampled image features that can be supported by an implementation

Members

This structure describes the following feature:

Description

If the PhysicalDeviceCornerSampledImageFeaturesNV structure is included in the pNext chain of the PhysicalDeviceFeatures2 structure passed to getPhysicalDeviceFeatures2, it is filled in to indicate whether each corresponding feature is supported. PhysicalDeviceCornerSampledImageFeaturesNV can also be used in the pNext chain of DeviceCreateInfo to selectively enable these features.

Valid Usage (Implicit)

See Also

VK_NV_corner_sampled_image, Bool32, StructureType

Constructors

PhysicalDeviceCornerSampledImageFeaturesNV

Fields

• cornerSampledImage :: Bool

  cornerSampledImage specifies whether images can be created with a ImageCreateInfo::flags containing IMAGE_CREATE_CORNER_SAMPLED_BIT_NV. See Corner-Sampled Images.

Instances

Eq PhysicalDeviceCornerSampledImageFeaturesNV

Defined in Vulkan.Extensions.VK_NV_corner_sampled_image

Methods

(==) :: PhysicalDeviceCornerSampledImageFeaturesNV -> PhysicalDeviceCornerSampledImageFeaturesNV -> Bool

(/=) :: PhysicalDeviceCornerSampledImageFeaturesNV -> PhysicalDeviceCornerSampledImageFeaturesNV -> Bool

Show PhysicalDeviceCornerSampledImageFeaturesNV

Defined in Vulkan.Extensions.VK_NV_corner_sampled_image

Methods

showsPrec :: Int -> PhysicalDeviceCornerSampledImageFeaturesNV -> ShowS

show :: PhysicalDeviceCornerSampledImageFeaturesNV -> String

showList :: [PhysicalDeviceCornerSampledImageFeaturesNV] -> ShowS

Storable PhysicalDeviceCornerSampledImageFeaturesNV

Defined in Vulkan.Extensions.VK_NV_corner_sampled_image

Methods

sizeOf :: PhysicalDeviceCornerSampledImageFeaturesNV -> Int

alignment :: PhysicalDeviceCornerSampledImageFeaturesNV -> Int

peekElemOff :: Ptr PhysicalDeviceCornerSampledImageFeaturesNV -> Int -> IO PhysicalDeviceCornerSampledImageFeaturesNV

pokeElemOff :: Ptr PhysicalDeviceCornerSampledImageFeaturesNV -> Int -> PhysicalDeviceCornerSampledImageFeaturesNV -> IO ()

peekByteOff :: Ptr b -> Int -> IO PhysicalDeviceCornerSampledImageFeaturesNV

pokeByteOff :: Ptr b -> Int -> PhysicalDeviceCornerSampledImageFeaturesNV -> IO ()

peek :: Ptr PhysicalDeviceCornerSampledImageFeaturesNV -> IO PhysicalDeviceCornerSampledImageFeaturesNV

poke :: Ptr PhysicalDeviceCornerSampledImageFeaturesNV -> PhysicalDeviceCornerSampledImageFeaturesNV -> IO ()

FromCStruct PhysicalDeviceCornerSampledImageFeaturesNV

Defined in Vulkan.Extensions.VK_NV_corner_sampled_image

Methods

peekCStruct :: Ptr PhysicalDeviceCornerSampledImageFeaturesNV -> IO PhysicalDeviceCornerSampledImageFeaturesNV

ToCStruct PhysicalDeviceCornerSampledImageFeaturesNV

Defined in Vulkan.Extensions.VK_NV_corner_sampled_image

Methods

withCStruct :: PhysicalDeviceCornerSampledImageFeaturesNV -> (Ptr PhysicalDeviceCornerSampledImageFeaturesNV -> IO b) -> IO b

pokeCStruct :: Ptr PhysicalDeviceCornerSampledImageFeaturesNV -> PhysicalDeviceCornerSampledImageFeaturesNV -> IO b -> IO b

withZeroCStruct :: (Ptr PhysicalDeviceCornerSampledImageFeaturesNV -> IO b) -> IO b

pokeZeroCStruct :: Ptr PhysicalDeviceCornerSampledImageFeaturesNV -> IO b -> IO b

cStructSize :: Int

cStructAlignment :: Int

Zero PhysicalDeviceCornerSampledImageFeaturesNV

Defined in Vulkan.Extensions.VK_NV_corner_sampled_image

Methods

zero :: PhysicalDeviceCornerSampledImageFeaturesNV

type NV_CORNER_SAMPLED_IMAGE_SPEC_VERSION = 2

pattern NV_CORNER_SAMPLED_IMAGE_SPEC_VERSION :: forall a. Integral a => a

type NV_CORNER_SAMPLED_IMAGE_EXTENSION_NAME = "VK_NV_corner_sampled_image"

pattern NV_CORNER_SAMPLED_IMAGE_EXTENSION_NAME :: forall a. (Eq a, IsString a) => a