Samplers

VkSampler objects represent the state of an image sampler which is used by the implementation to read image data and apply filtering and other transformations for the shader.

Samplers are represented by VkSampler handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkSampler)

To create a sampler object, call:

// Provided by VK_VERSION_1_0
VkResult vkCreateSampler(
    VkDevice                                    device,
    const VkSamplerCreateInfo*                  pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkSampler*                                  pSampler);

  • device is the logical device that creates the sampler.

  • pCreateInfo is a pointer to a VkSamplerCreateInfo structure specifying the state of the sampler object.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

  • pSampler is a pointer to a VkSampler handle in which the resulting sampler object is returned.

Valid Usage
Valid Usage (Implicit)

  • VUID-vkCreateSampler-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkCreateSampler-pCreateInfo-parameter
    pCreateInfo must be a valid pointer to a valid VkSamplerCreateInfo structure

  • VUID-vkCreateSampler-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkCreateSampler-pSampler-parameter
    pSampler must be a valid pointer to a VkSampler handle

Return Codes
Success
Failure

The VkSamplerCreateInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkSamplerCreateInfo {
    VkStructureType         sType;
    const void*             pNext;
    VkSamplerCreateFlags    flags;
    VkFilter                magFilter;
    VkFilter                minFilter;
    VkSamplerMipmapMode     mipmapMode;
    VkSamplerAddressMode    addressModeU;
    VkSamplerAddressMode    addressModeV;
    VkSamplerAddressMode    addressModeW;
    float                   mipLodBias;
    VkBool32                anisotropyEnable;
    float                   maxAnisotropy;
    VkBool32                compareEnable;
    VkCompareOp             compareOp;
    float                   minLod;
    float                   maxLod;
    VkBorderColor           borderColor;
    VkBool32                unnormalizedCoordinates;
} VkSamplerCreateInfo;

  • sType is a VkStructureType value identifying this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is a bitmask of VkSamplerCreateFlagBits describing additional parameters of the sampler.

  • magFilter is a VkFilter value specifying the magnification filter to apply to lookups.

  • minFilter is a VkFilter value specifying the minification filter to apply to lookups.

  • mipmapMode is a VkSamplerMipmapMode value specifying the mipmap filter to apply to lookups.

  • addressModeU is a VkSamplerAddressMode value specifying the wrapping operation used when the i coordinate used to sample the image would be out of bounds.

  • addressModeV is a VkSamplerAddressMode value specifying the wrapping operation used when the j coordinate used to sample the image would be out of bounds.

  • addressModeW is a VkSamplerAddressMode value specifying the wrapping operation used when the k coordinate used to sample the image would be out of bounds. If unnormalizedCoordinates is VK_TRUE, addressModeW is ignored.

  • mipLodBias is the bias to be added to mipmap LOD calculation and bias provided by image sampling functions in SPIR-V, as described in the LOD Operation section.

  • anisotropyEnable is VK_TRUE to enable anisotropic filtering, as described in the Texel Anisotropic Filtering section, or VK_FALSE otherwise.

  • maxAnisotropy is the anisotropy value clamp used by the sampler when anisotropyEnable is VK_TRUE. If anisotropyEnable is VK_FALSE, maxAnisotropy is ignored.

  • compareEnable is VK_TRUE to enable comparison against a reference value during lookups, or VK_FALSE otherwise.

    • Note: Some implementations will default to shader state if this member does not match.

  • compareOp is a VkCompareOp value specifying the comparison operator to apply to fetched data before filtering as described in the Depth Compare Operation section.

  • minLod is used to clamp the minimum of the computed LOD value.

  • maxLod is used to clamp the maximum of the computed LOD value. To avoid clamping the maximum value, set maxLod to the constant VK_LOD_CLAMP_NONE.

  • borderColor is a VkBorderColor value specifying the predefined border color to use.

  • unnormalizedCoordinates controls whether to use unnormalized or normalized texel coordinates to address texels of the image. When unnormalizedCoordinates is VK_TRUE, the range of the image coordinates used to lookup the texel is in the range of zero to the image size in each dimension. When unnormalizedCoordinates is VK_FALSE, the range of image coordinates is zero to one.

    When unnormalizedCoordinates is VK_TRUE, images the sampler is used with in the shader have the following requirements:

    • The viewType must be either VK_IMAGE_VIEW_TYPE_1D or VK_IMAGE_VIEW_TYPE_2D.

    • The image view must have a single layer and a single mip level.

      When unnormalizedCoordinates is VK_TRUE, image built-in functions in the shader that use the sampler have the following requirements:

    • The functions must not use projection.

    • The functions must not use offsets.

Mapping of OpenGL to Vulkan Filter Modes

magFilter values of VK_FILTER_NEAREST and VK_FILTER_LINEAR directly correspond to GL_NEAREST and GL_LINEAR magnification filters. minFilter and mipmapMode combine to correspond to the similarly named OpenGL minification filter of GL_minFilter_MIPMAP_mipmapMode (e.g. minFilter of VK_FILTER_LINEAR and mipmapMode of VK_SAMPLER_MIPMAP_MODE_NEAREST correspond to GL_LINEAR_MIPMAP_NEAREST).

There are no Vulkan filter modes that directly correspond to OpenGL minification filters of GL_LINEAR or GL_NEAREST, but they can be emulated using VK_SAMPLER_MIPMAP_MODE_NEAREST, minLod = 0, and maxLod = 0.25, and using minFilter = VK_FILTER_LINEAR or minFilter = VK_FILTER_NEAREST, respectively.

Note that using a maxLod of zero would cause magnification to always be performed, and the magFilter to always be used. This is valid, just not an exact match for OpenGL behavior. Clamping the maximum LOD to 0.25 allows the λ value to be non-zero and minification to be performed, while still always rounding down to the base level. If the minFilter and magFilter are equal, then using a maxLod of zero also works.

The maximum number of sampler objects which can be simultaneously created on a device is implementation-dependent and specified by the maxSamplerAllocationCount member of the VkPhysicalDeviceLimits structure.

For historical reasons, if maxSamplerAllocationCount is exceeded, some implementations may return VK_ERROR_TOO_MANY_OBJECTS. Exceeding this limit will result in undefined behavior, and an application should not rely on the use of the returned error code in order to identify when the limit is reached.

Since VkSampler is a non-dispatchable handle type, implementations may return the same handle for sampler state vectors that are identical. In such cases, all such objects would only count once against the maxSamplerAllocationCount limit.

Valid Usage
Valid Usage (Implicit)

VK_LOD_CLAMP_NONE is a special constant value used for VkSamplerCreateInfo::maxLod to indicate that maximum LOD clamping should not be performed.

#define VK_LOD_CLAMP_NONE                 1000.0F

Bits which can be set in VkSamplerCreateInfo::flags, specifying additional parameters of a sampler, are:

// Provided by VK_VERSION_1_0
typedef enum VkSamplerCreateFlagBits {
  // Provided by VK_EXT_fragment_density_map
    VK_SAMPLER_CREATE_SUBSAMPLED_BIT_EXT = 0x00000001,
  // Provided by VK_EXT_fragment_density_map
    VK_SAMPLER_CREATE_SUBSAMPLED_COARSE_RECONSTRUCTION_BIT_EXT = 0x00000002,
  // Provided by VK_EXT_descriptor_buffer
    VK_SAMPLER_CREATE_DESCRIPTOR_BUFFER_CAPTURE_REPLAY_BIT_EXT = 0x00000008,
  // Provided by VK_EXT_non_seamless_cube_map
    VK_SAMPLER_CREATE_NON_SEAMLESS_CUBE_MAP_BIT_EXT = 0x00000004,
  // Provided by VK_QCOM_image_processing
    VK_SAMPLER_CREATE_IMAGE_PROCESSING_BIT_QCOM = 0x00000010,
} VkSamplerCreateFlagBits;

The approximations used when VK_SAMPLER_CREATE_SUBSAMPLED_COARSE_RECONSTRUCTION_BIT_EXT is specified are implementation defined. Some implementations may interpolate between fragment density levels in a subsampled image. In that case, this bit may be used to decide whether the interpolation factors are calculated per fragment or at a coarser granularity.

 
// Provided by VK_VERSION_1_0
typedef VkFlags VkSamplerCreateFlags;

VkSamplerCreateFlags is a bitmask type for setting a mask of zero or more VkSamplerCreateFlagBits.

The VkSamplerReductionModeCreateInfo structure is defined as:

// Provided by VK_VERSION_1_2
typedef struct VkSamplerReductionModeCreateInfo {
    VkStructureType           sType;
    const void*               pNext;
    VkSamplerReductionMode    reductionMode;
} VkSamplerReductionModeCreateInfo;
// Provided by VK_EXT_sampler_filter_minmax
// Equivalent to VkSamplerReductionModeCreateInfo
typedef VkSamplerReductionModeCreateInfo VkSamplerReductionModeCreateInfoEXT;

  • sType is a VkStructureType value identifying this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • reductionMode is a VkSamplerReductionMode value controlling how texture filtering combines texel values.

If the pNext chain of VkSamplerCreateInfo includes a VkSamplerReductionModeCreateInfo structure, then that structure includes a mode controlling how texture filtering combines texel values.

If this structure is not present, reductionMode is considered to be VK_SAMPLER_REDUCTION_MODE_WEIGHTED_AVERAGE.

Valid Usage (Implicit)

Reduction modes are specified by VkSamplerReductionMode, which takes values:

// Provided by VK_VERSION_1_2
typedef enum VkSamplerReductionMode {
    VK_SAMPLER_REDUCTION_MODE_WEIGHTED_AVERAGE = 0,
    VK_SAMPLER_REDUCTION_MODE_MIN = 1,
    VK_SAMPLER_REDUCTION_MODE_MAX = 2,
  // Provided by VK_QCOM_filter_cubic_clamp
    VK_SAMPLER_REDUCTION_MODE_WEIGHTED_AVERAGE_RANGECLAMP_QCOM = 1000521000,
  // Provided by VK_EXT_sampler_filter_minmax
    VK_SAMPLER_REDUCTION_MODE_WEIGHTED_AVERAGE_EXT = VK_SAMPLER_REDUCTION_MODE_WEIGHTED_AVERAGE,
  // Provided by VK_EXT_sampler_filter_minmax
    VK_SAMPLER_REDUCTION_MODE_MIN_EXT = VK_SAMPLER_REDUCTION_MODE_MIN,
  // Provided by VK_EXT_sampler_filter_minmax
    VK_SAMPLER_REDUCTION_MODE_MAX_EXT = VK_SAMPLER_REDUCTION_MODE_MAX,
} VkSamplerReductionMode;
// Provided by VK_EXT_sampler_filter_minmax
// Equivalent to VkSamplerReductionMode
typedef VkSamplerReductionMode VkSamplerReductionModeEXT;

The VkSamplerCubicWeightsCreateInfoQCOM structure is defined as:

// Provided by VK_QCOM_filter_cubic_weights
typedef struct VkSamplerCubicWeightsCreateInfoQCOM {
    VkStructureType             sType;
    const void*                 pNext;
    VkCubicFilterWeightsQCOM    cubicWeights;
} VkSamplerCubicWeightsCreateInfoQCOM;

  • sType is a VkStructureType value identifying this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • cubicWeights is a VkCubicFilterWeightsQCOM value controlling which cubic weights are used.

If the pNext chain of VkSamplerCreateInfo includes a VkSamplerCubicWeightsCreateInfoQCOM structure, then that structure specifies which cubic weights are used.

If that structure is not present, cubicWeights is considered to be VK_CUBIC_FILTER_WEIGHTS_CATMULL_ROM_QCOM.

Valid Usage (Implicit)

Possible values of the VkSamplerCubicWeightsCreateInfoQCOM::cubicWeights, specifying cubic weights used in Texel Cubic Filtering are:

// Provided by VK_QCOM_filter_cubic_weights
typedef enum VkCubicFilterWeightsQCOM {
    VK_CUBIC_FILTER_WEIGHTS_CATMULL_ROM_QCOM = 0,
    VK_CUBIC_FILTER_WEIGHTS_ZERO_TANGENT_CARDINAL_QCOM = 1,
    VK_CUBIC_FILTER_WEIGHTS_B_SPLINE_QCOM = 2,
    VK_CUBIC_FILTER_WEIGHTS_MITCHELL_NETRAVALI_QCOM = 3,
} VkCubicFilterWeightsQCOM;

Possible values of the VkSamplerCreateInfo::magFilter and minFilter parameters, specifying filters used for texture lookups, are:

// Provided by VK_VERSION_1_0
typedef enum VkFilter {
    VK_FILTER_NEAREST = 0,
    VK_FILTER_LINEAR = 1,
  // Provided by VK_EXT_filter_cubic
    VK_FILTER_CUBIC_EXT = 1000015000,
  // Provided by VK_IMG_filter_cubic
    VK_FILTER_CUBIC_IMG = VK_FILTER_CUBIC_EXT,
} VkFilter;

These filters are described in detail in Texel Filtering.

Possible values of the VkSamplerCreateInfo::mipmapMode, specifying the mipmap mode used for texture lookups, are:

// Provided by VK_VERSION_1_0
typedef enum VkSamplerMipmapMode {
    VK_SAMPLER_MIPMAP_MODE_NEAREST = 0,
    VK_SAMPLER_MIPMAP_MODE_LINEAR = 1,
} VkSamplerMipmapMode;

These modes are described in detail in Texel Filtering.

Possible values of the VkSamplerCreateInfo::addressMode* parameters, corresponding to different wrapping operations used during sampling, are:

// Provided by VK_VERSION_1_0
typedef enum VkSamplerAddressMode {
    VK_SAMPLER_ADDRESS_MODE_REPEAT = 0,
    VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT = 1,
    VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE = 2,
    VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER = 3,
  // Provided by VK_VERSION_1_2, VK_KHR_sampler_mirror_clamp_to_edge
    VK_SAMPLER_ADDRESS_MODE_MIRROR_CLAMP_TO_EDGE = 4,
  // Provided by VK_KHR_sampler_mirror_clamp_to_edge
  // VK_SAMPLER_ADDRESS_MODE_MIRROR_CLAMP_TO_EDGE_KHR is a legacy alias
    VK_SAMPLER_ADDRESS_MODE_MIRROR_CLAMP_TO_EDGE_KHR = VK_SAMPLER_ADDRESS_MODE_MIRROR_CLAMP_TO_EDGE,
} VkSamplerAddressMode;

Comparison operators compare a reference and a test value, and return a true (“passed”) or false (“failed”) value depending on the comparison operator chosen. The supported operators are:

// Provided by VK_VERSION_1_0
typedef enum VkCompareOp {
    VK_COMPARE_OP_NEVER = 0,
    VK_COMPARE_OP_LESS = 1,
    VK_COMPARE_OP_EQUAL = 2,
    VK_COMPARE_OP_LESS_OR_EQUAL = 3,
    VK_COMPARE_OP_GREATER = 4,
    VK_COMPARE_OP_NOT_EQUAL = 5,
    VK_COMPARE_OP_GREATER_OR_EQUAL = 6,
    VK_COMPARE_OP_ALWAYS = 7,
} VkCompareOp;

Comparison operators are used for:

Each such use describes how the reference and test values for that comparison are determined.

Possible values of VkSamplerCreateInfo::borderColor, specifying the border color used for texture lookups, are:

// Provided by VK_VERSION_1_0
typedef enum VkBorderColor {
    VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK = 0,
    VK_BORDER_COLOR_INT_TRANSPARENT_BLACK = 1,
    VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK = 2,
    VK_BORDER_COLOR_INT_OPAQUE_BLACK = 3,
    VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE = 4,
    VK_BORDER_COLOR_INT_OPAQUE_WHITE = 5,
  // Provided by VK_EXT_custom_border_color
    VK_BORDER_COLOR_FLOAT_CUSTOM_EXT = 1000287003,
  // Provided by VK_EXT_custom_border_color
    VK_BORDER_COLOR_INT_CUSTOM_EXT = 1000287004,
} VkBorderColor;

These colors are described in detail in Border Replacement.

To destroy a sampler, call:

// Provided by VK_VERSION_1_0
void vkDestroySampler(
    VkDevice                                    device,
    VkSampler                                   sampler,
    const VkAllocationCallbacks*                pAllocator);

  • device is the logical device that destroys the sampler.

  • sampler is the sampler to destroy.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

Valid Usage

  • VUID-vkDestroySampler-sampler-01082
    All submitted commands that refer to sampler must have completed execution

  • VUID-vkDestroySampler-sampler-01083
    If VkAllocationCallbacks were provided when sampler was created, a compatible set of callbacks must be provided here

  • VUID-vkDestroySampler-sampler-01084
    If no VkAllocationCallbacks were provided when sampler was created, pAllocator must be NULL

Valid Usage (Implicit)

  • VUID-vkDestroySampler-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkDestroySampler-sampler-parameter
    If sampler is not VK_NULL_HANDLE, sampler must be a valid VkSampler handle

  • VUID-vkDestroySampler-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkDestroySampler-sampler-parent
    If sampler is a valid handle, it must have been created, allocated, or retrieved from device

Host Synchronization

  • Host access to sampler must be externally synchronized

Sampler Y′CBCR Conversion

To create a sampler with Y′CBCR conversion enabled, add a VkSamplerYcbcrConversionInfo structure to the pNext chain of the VkSamplerCreateInfo structure. To create a sampler Y′CBCR conversion, the samplerYcbcrConversion feature must be enabled. Conversion must be fixed at pipeline creation time, through use of a combined image sampler with an immutable sampler in VkDescriptorSetLayoutBinding.

A VkSamplerYcbcrConversionInfo must be provided for samplers to be used with image views that access VK_IMAGE_ASPECT_COLOR_BIT if the format is one of the formats that require a sampler Y′CBCR conversion , or if the image view has an external format .

The VkSamplerYcbcrConversionInfo structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkSamplerYcbcrConversionInfo {
    VkStructureType             sType;
    const void*                 pNext;
    VkSamplerYcbcrConversion    conversion;
} VkSamplerYcbcrConversionInfo;
// Provided by VK_KHR_sampler_ycbcr_conversion
// Equivalent to VkSamplerYcbcrConversionInfo
typedef VkSamplerYcbcrConversionInfo VkSamplerYcbcrConversionInfoKHR;
Valid Usage (Implicit)

A sampler Y′CBCR conversion is an opaque representation of a device-specific sampler Y′CBCR conversion description, represented as a VkSamplerYcbcrConversion handle:

// Provided by VK_VERSION_1_1
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkSamplerYcbcrConversion)
// Provided by VK_KHR_sampler_ycbcr_conversion
// Equivalent to VkSamplerYcbcrConversion
typedef VkSamplerYcbcrConversion VkSamplerYcbcrConversionKHR;

To create a VkSamplerYcbcrConversion, call:

// Provided by VK_VERSION_1_1
VkResult vkCreateSamplerYcbcrConversion(
    VkDevice                                    device,
    const VkSamplerYcbcrConversionCreateInfo*   pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkSamplerYcbcrConversion*                   pYcbcrConversion);
// Provided by VK_KHR_sampler_ycbcr_conversion
// Equivalent to vkCreateSamplerYcbcrConversion
VkResult vkCreateSamplerYcbcrConversionKHR(
    VkDevice                                    device,
    const VkSamplerYcbcrConversionCreateInfo*   pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkSamplerYcbcrConversion*                   pYcbcrConversion);

  • device is the logical device that creates the sampler Y′CBCR conversion.

  • pCreateInfo is a pointer to a VkSamplerYcbcrConversionCreateInfo structure specifying the requested sampler Y′CBCR conversion.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

  • pYcbcrConversion is a pointer to a VkSamplerYcbcrConversion handle in which the resulting sampler Y′CBCR conversion is returned.

The interpretation of the configured sampler Y′CBCR conversion is described in more detail in the description of sampler Y′CBCR conversion in the Image Operations chapter.

Valid Usage
Valid Usage (Implicit)

  • VUID-vkCreateSamplerYcbcrConversion-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkCreateSamplerYcbcrConversion-pCreateInfo-parameter
    pCreateInfo must be a valid pointer to a valid VkSamplerYcbcrConversionCreateInfo structure

  • VUID-vkCreateSamplerYcbcrConversion-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkCreateSamplerYcbcrConversion-pYcbcrConversion-parameter
    pYcbcrConversion must be a valid pointer to a VkSamplerYcbcrConversion handle

Return Codes
Success
Failure

The VkSamplerYcbcrConversionCreateInfo structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkSamplerYcbcrConversionCreateInfo {
    VkStructureType                  sType;
    const void*                      pNext;
    VkFormat                         format;
    VkSamplerYcbcrModelConversion    ycbcrModel;
    VkSamplerYcbcrRange              ycbcrRange;
    VkComponentMapping               components;
    VkChromaLocation                 xChromaOffset;
    VkChromaLocation                 yChromaOffset;
    VkFilter                         chromaFilter;
    VkBool32                         forceExplicitReconstruction;
} VkSamplerYcbcrConversionCreateInfo;
// Provided by VK_KHR_sampler_ycbcr_conversion
// Equivalent to VkSamplerYcbcrConversionCreateInfo
typedef VkSamplerYcbcrConversionCreateInfo VkSamplerYcbcrConversionCreateInfoKHR;

  • sType is a VkStructureType value identifying this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • format is the format of the image from which color information will be retrieved.

  • ycbcrModel describes the color matrix for conversion between color models.

  • ycbcrRange describes whether the encoded values have headroom and foot room, or whether the encoding uses the full numerical range.

  • components applies a swizzle based on VkComponentSwizzle enums prior to range expansion and color model conversion.

  • xChromaOffset describes the sample location associated with downsampled chroma components in the x dimension. xChromaOffset has no effect for formats in which chroma components are not downsampled horizontally.

  • yChromaOffset describes the sample location associated with downsampled chroma components in the y dimension. yChromaOffset has no effect for formats in which the chroma components are not downsampled vertically.

  • chromaFilter is the filter for chroma reconstruction.

  • forceExplicitReconstruction can be used to ensure that reconstruction is done explicitly, if supported.

Setting forceExplicitReconstruction to VK_TRUE may have a performance penalty on implementations where explicit reconstruction is not the default mode of operation.

If format supports VK_FORMAT_FEATURE_SAMPLED_IMAGE_YCBCR_CONVERSION_CHROMA_RECONSTRUCTION_EXPLICIT_BIT the forceExplicitReconstruction value behaves as if it were VK_TRUE.

If the pNext chain includes a VkExternalFormatANDROID structure with non-zero externalFormat member, the sampler Y′CBCR conversion object represents an external format conversion, and format must be VK_FORMAT_UNDEFINED. Such conversions must only be used to sample image views with a matching external format. When creating an external format conversion, the value of components is ignored.

Valid Usage
Valid Usage (Implicit)

If chromaFilter is VK_FILTER_NEAREST, chroma samples are reconstructed to luma component resolution using nearest-neighbour sampling. Otherwise, chroma samples are reconstructed using interpolation. More details can be found in the description of sampler Y′CBCR conversion in the Image Operations chapter.

VkSamplerYcbcrModelConversion defines the conversion from the source color model to the shader color model. Possible values are:

// Provided by VK_VERSION_1_1
typedef enum VkSamplerYcbcrModelConversion {
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY = 0,
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY = 1,
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709 = 2,
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601 = 3,
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020 = 4,
  // Provided by VK_KHR_sampler_ycbcr_conversion
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY,
  // Provided by VK_KHR_sampler_ycbcr_conversion
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY,
  // Provided by VK_KHR_sampler_ycbcr_conversion
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_709,
  // Provided by VK_KHR_sampler_ycbcr_conversion
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_601,
  // Provided by VK_KHR_sampler_ycbcr_conversion
    VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020_KHR = VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_2020,
} VkSamplerYcbcrModelConversion;
// Provided by VK_KHR_sampler_ycbcr_conversion
// Equivalent to VkSamplerYcbcrModelConversion
typedef VkSamplerYcbcrModelConversion VkSamplerYcbcrModelConversionKHR;

In the VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_* color models, for the input to the sampler Y′CBCR range expansion and model conversion:

  • the Y (Y′ luma) component corresponds to the G component of an RGB image.

  • the CB (CB or “U” blue color difference) component corresponds to the B component of an RGB image.

  • the CR (CR or “V” red color difference) component corresponds to the R component of an RGB image.

  • the alpha component, if present, is not modified by color model conversion.

These rules reflect the mapping of components after the component swizzle operation (controlled by VkSamplerYcbcrConversionCreateInfo::components).

For example, an “YUVA” 32-bit format comprising four 8-bit components can be implemented as VK_FORMAT_R8G8B8A8_UNORM with a component mapping:

The VkSamplerYcbcrRange enum describes whether color components are encoded using the full range of numerical values or whether values are reserved for headroom and foot room. VkSamplerYcbcrRange is defined as:

// Provided by VK_VERSION_1_1
typedef enum VkSamplerYcbcrRange {
    VK_SAMPLER_YCBCR_RANGE_ITU_FULL = 0,
    VK_SAMPLER_YCBCR_RANGE_ITU_NARROW = 1,
  // Provided by VK_KHR_sampler_ycbcr_conversion
    VK_SAMPLER_YCBCR_RANGE_ITU_FULL_KHR = VK_SAMPLER_YCBCR_RANGE_ITU_FULL,
  // Provided by VK_KHR_sampler_ycbcr_conversion
    VK_SAMPLER_YCBCR_RANGE_ITU_NARROW_KHR = VK_SAMPLER_YCBCR_RANGE_ITU_NARROW,
} VkSamplerYcbcrRange;
// Provided by VK_KHR_sampler_ycbcr_conversion
// Equivalent to VkSamplerYcbcrRange
typedef VkSamplerYcbcrRange VkSamplerYcbcrRangeKHR;

  • VK_SAMPLER_YCBCR_RANGE_ITU_FULL specifies that the full range of the encoded values are valid and interpreted according to the ITU “full range” quantization rules.

  • VK_SAMPLER_YCBCR_RANGE_ITU_NARROW specifies that headroom and foot room are reserved in the numerical range of encoded values, and the remaining values are expanded according to the ITU “narrow range” quantization rules.

The formulae for these conversions is described in the Sampler Y′CBCR Range Expansion section of the Image Operations chapter.

No range modification takes place if ycbcrModel is VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY; the ycbcrRange field of VkSamplerYcbcrConversionCreateInfo is ignored in this case.

The VkChromaLocation enum defines the location of downsampled chroma component samples relative to the luma samples, and is defined as:

// Provided by VK_VERSION_1_1
typedef enum VkChromaLocation {
    VK_CHROMA_LOCATION_COSITED_EVEN = 0,
    VK_CHROMA_LOCATION_MIDPOINT = 1,
  // Provided by VK_KHR_sampler_ycbcr_conversion
    VK_CHROMA_LOCATION_COSITED_EVEN_KHR = VK_CHROMA_LOCATION_COSITED_EVEN,
  // Provided by VK_KHR_sampler_ycbcr_conversion
    VK_CHROMA_LOCATION_MIDPOINT_KHR = VK_CHROMA_LOCATION_MIDPOINT,
} VkChromaLocation;
// Provided by VK_KHR_sampler_ycbcr_conversion
// Equivalent to VkChromaLocation
typedef VkChromaLocation VkChromaLocationKHR;

Applications can enable sRGB to linear conversion for the R, G, and B components of a Y′CBCR image during sampling by including VkSamplerYcbcrConversionYcbcrDegammaCreateInfoQCOM structure in the pNext chain of VkSamplerYcbcrConversionCreateInfo.

The VkSamplerYcbcrConversionYcbcrDegammaCreateInfoQCOM structure is defined as:

// Provided by VK_QCOM_ycbcr_degamma
typedef struct VkSamplerYcbcrConversionYcbcrDegammaCreateInfoQCOM {
    VkStructureType    sType;
    void*              pNext;
    VkBool32           enableYDegamma;
    VkBool32           enableCbCrDegamma;
} VkSamplerYcbcrConversionYcbcrDegammaCreateInfoQCOM;

  • sType is a VkStructureType value identifying this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • enableYDegamma indicates sRGB to linear conversion is enabled for the G component.

  • enableCbCrDegamma indicates sRGB to linear conversion is enabled for the R and B components.

Valid Usage (Implicit)

To destroy a sampler Y′CBCR conversion, call:

// Provided by VK_VERSION_1_1
void vkDestroySamplerYcbcrConversion(
    VkDevice                                    device,
    VkSamplerYcbcrConversion                    ycbcrConversion,
    const VkAllocationCallbacks*                pAllocator);
// Provided by VK_KHR_sampler_ycbcr_conversion
// Equivalent to vkDestroySamplerYcbcrConversion
void vkDestroySamplerYcbcrConversionKHR(
    VkDevice                                    device,
    VkSamplerYcbcrConversion                    ycbcrConversion,
    const VkAllocationCallbacks*                pAllocator);

  • device is the logical device that destroys the Y′CBCR conversion.

  • ycbcrConversion is the conversion to destroy.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

Valid Usage (Implicit)

  • VUID-vkDestroySamplerYcbcrConversion-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkDestroySamplerYcbcrConversion-ycbcrConversion-parameter
    If ycbcrConversion is not VK_NULL_HANDLE, ycbcrConversion must be a valid VkSamplerYcbcrConversion handle

  • VUID-vkDestroySamplerYcbcrConversion-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkDestroySamplerYcbcrConversion-ycbcrConversion-parent
    If ycbcrConversion is a valid handle, it must have been created, allocated, or retrieved from device

Host Synchronization

  • Host access to ycbcrConversion must be externally synchronized

In addition to the predefined border color values, applications can provide a custom border color value by including the VkSamplerCustomBorderColorCreateInfoEXT structure in the VkSamplerCreateInfo::pNext chain.

The VkSamplerCustomBorderColorCreateInfoEXT structure is defined as:

// Provided by VK_EXT_custom_border_color
typedef struct VkSamplerCustomBorderColorCreateInfoEXT {
    VkStructureType      sType;
    const void*          pNext;
    VkClearColorValue    customBorderColor;
    VkFormat             format;
} VkSamplerCustomBorderColorCreateInfoEXT;

If format is a depth/stencil format, the aspect is determined by the value of VkSamplerCreateInfo::borderColor. If VkSamplerCreateInfo::borderColor is VK_BORDER_COLOR_FLOAT_CUSTOM_EXT, the depth aspect is considered. If VkSamplerCreateInfo::borderColor is VK_BORDER_COLOR_INT_CUSTOM_EXT, the stencil aspect is considered.

If format is VK_FORMAT_UNDEFINED, the VkSamplerCreateInfo::borderColor is VK_BORDER_COLOR_INT_CUSTOM_EXT, and the sampler is used with an image with a stencil format, then the implementation must source the custom border color from either the first or second components of VkSamplerCreateInfo::borderColor and should source it from the first component.
Valid Usage
Valid Usage (Implicit)

If the sampler is created with VK_BORDER_COLOR_FLOAT_OPAQUE_BLACK, VK_BORDER_COLOR_INT_OPAQUE_BLACK, VK_BORDER_COLOR_FLOAT_CUSTOM_EXT, or VK_BORDER_COLOR_INT_CUSTOM_EXT borderColor, and that sampler will be combined with an image view that does not have an identity swizzle, and VkPhysicalDeviceBorderColorSwizzleFeaturesEXT::borderColorSwizzleFromImage is not enabled, then it is necessary to specify the component mapping of the border color, by including the VkSamplerBorderColorComponentMappingCreateInfoEXT structure in the VkSamplerCreateInfo::pNext chain, to get defined results.

The VkSamplerBorderColorComponentMappingCreateInfoEXT structure is defined as:

// Provided by VK_EXT_border_color_swizzle
typedef struct VkSamplerBorderColorComponentMappingCreateInfoEXT {
    VkStructureType       sType;
    const void*           pNext;
    VkComponentMapping    components;
    VkBool32              srgb;
} VkSamplerBorderColorComponentMappingCreateInfoEXT;

  • sType is a VkStructureType value identifying this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • components is a VkComponentMapping structure specifying a remapping of the border color components.

  • srgb indicates that the sampler will be combined with an image view that has an image format which is sRGB encoded.

The VkComponentMapping components member describes a remapping from components of the border color to components of the vector returned by shader image instructions when the border color is used.

Valid Usage

  • VUID-VkSamplerBorderColorComponentMappingCreateInfoEXT-borderColorSwizzle-06437
    The borderColorSwizzle feature must be enabled

Valid Usage (Implicit)

The VkSamplerBlockMatchWindowCreateInfoQCOM structure is defined as:

// Provided by VK_QCOM_image_processing2
typedef struct VkSamplerBlockMatchWindowCreateInfoQCOM {
    VkStructureType                      sType;
    const void*                          pNext;
    VkExtent2D                           windowExtent;
    VkBlockMatchWindowCompareModeQCOM    windowCompareMode;
} VkSamplerBlockMatchWindowCreateInfoQCOM;

  • sType is a VkStructureType value identifying this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • windowExtent is a VkExtent2D specifying a the width and height of the block match window.

  • windowCompareMode is a VkBlockMatchWindowCompareModeQCOM specifying the compare mode.

Valid Usage
Valid Usage (Implicit)

The VkBlockMatchWindowCompareModeQCOM enum describes how block match values within the window are compared. VkBlockMatchWindowCompareModeQCOM is defined as:

// Provided by VK_QCOM_image_processing2
typedef enum VkBlockMatchWindowCompareModeQCOM {
    VK_BLOCK_MATCH_WINDOW_COMPARE_MODE_MIN_QCOM = 0,
    VK_BLOCK_MATCH_WINDOW_COMPARE_MODE_MAX_QCOM = 1,
} VkBlockMatchWindowCompareModeQCOM;