C Specification
Multisample values in a multisample attachment are combined according to the resolve mode used:
// Provided by VK_VERSION_1_2
typedef enum VkResolveModeFlagBits {
VK_RESOLVE_MODE_NONE = 0,
VK_RESOLVE_MODE_SAMPLE_ZERO_BIT = 0x00000001,
VK_RESOLVE_MODE_AVERAGE_BIT = 0x00000002,
VK_RESOLVE_MODE_MIN_BIT = 0x00000004,
VK_RESOLVE_MODE_MAX_BIT = 0x00000008,
// Provided by VK_ANDROID_external_format_resolve with VK_KHR_dynamic_rendering or VK_VERSION_1_3
VK_RESOLVE_MODE_EXTERNAL_FORMAT_DOWNSAMPLE_BIT_ANDROID = 0x00000010,
// Provided by VK_EXT_custom_resolve with VK_KHR_dynamic_rendering or VK_VERSION_1_3
VK_RESOLVE_MODE_CUSTOM_BIT_EXT = 0x00000020,
// Provided by VK_KHR_depth_stencil_resolve
VK_RESOLVE_MODE_NONE_KHR = VK_RESOLVE_MODE_NONE,
// Provided by VK_KHR_depth_stencil_resolve
VK_RESOLVE_MODE_SAMPLE_ZERO_BIT_KHR = VK_RESOLVE_MODE_SAMPLE_ZERO_BIT,
// Provided by VK_KHR_depth_stencil_resolve
VK_RESOLVE_MODE_AVERAGE_BIT_KHR = VK_RESOLVE_MODE_AVERAGE_BIT,
// Provided by VK_KHR_depth_stencil_resolve
VK_RESOLVE_MODE_MIN_BIT_KHR = VK_RESOLVE_MODE_MIN_BIT,
// Provided by VK_KHR_depth_stencil_resolve
VK_RESOLVE_MODE_MAX_BIT_KHR = VK_RESOLVE_MODE_MAX_BIT,
// Provided by VK_ANDROID_external_format_resolve with VK_KHR_dynamic_rendering or VK_VERSION_1_3
// VK_RESOLVE_MODE_EXTERNAL_FORMAT_DOWNSAMPLE_ANDROID is a legacy alias
VK_RESOLVE_MODE_EXTERNAL_FORMAT_DOWNSAMPLE_ANDROID = VK_RESOLVE_MODE_EXTERNAL_FORMAT_DOWNSAMPLE_BIT_ANDROID,
} VkResolveModeFlagBits;
// Provided by VK_KHR_depth_stencil_resolve
// Equivalent to VkResolveModeFlagBits
typedef VkResolveModeFlagBits VkResolveModeFlagBitsKHR;
Description
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VK_RESOLVE_MODE_NONE specifies that no resolve operation is done.
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VK_RESOLVE_MODE_SAMPLE_ZERO_BIT specifies that result of the resolve operation is equal to the value of sample 0.
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VK_RESOLVE_MODE_AVERAGE_BIT specifies that result of the resolve operation is the average of the sample values.
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VK_RESOLVE_MODE_MIN_BIT specifies that result of the resolve operation is the minimum of the sample values.
-
VK_RESOLVE_MODE_MAX_BIT specifies that result of the resolve operation is the maximum of the sample values.
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VK_RESOLVE_MODE_EXTERNAL_FORMAT_DOWNSAMPLE_BIT_ANDROID specifies that rather than a multisample resolve, a single sampled color attachment will be downsampled into a Y′CBCR format image specified by an external Android format. Unlike other resolve modes, implementations can resolve multiple times during rendering, or even bypass writing to the color attachment altogether, as long as the final value is resolved to the resolve attachment. Values in the G, B, and R channels of the color attachment will be written to the Y, CB, and CR channels of the external format image, respectively. Chroma values are calculated as if sampling with a linear filter from the color attachment at full rate, at the location the chroma values sit according to VkPhysicalDeviceExternalFormatResolvePropertiesANDROID::
externalFormatResolveChromaOffsetX, VkPhysicalDeviceExternalFormatResolvePropertiesANDROID::externalFormatResolveChromaOffsetY, and the chroma sample rate of the resolved image. -
VK_RESOLVE_MODE_CUSTOM_BIT_EXT specifies that the attachment will be resolved by shaders in the render pass instead of fixed-function operations.
If no resolve mode is otherwise specified, VK_RESOLVE_MODE_AVERAGE_BIT is used.
If VK_RESOLVE_MODE_AVERAGE_BIT is used, and the source format is a floating-point or normalized type, the sample values for each pixel are resolved with implementation-defined numerical precision.
If the numeric format of the resolve attachment
uses sRGB encoding, the implementation should convert samples from
nonlinear to linear before averaging samples as described in the “sRGB
EOTF” section of the Khronos Data Format Specification.
In this case, the implementation must convert the linear averaged value to
nonlinear before writing the resolved result to resolve attachment.
If the maintenance10 feature is enabled,
whether a nonlinear to linear conversion happens for sRGB resolve is defined
by
resolveSrgbFormatAppliesTransferFunction.
This behavior can be overridden with appropriate
VK_*RESOLVE{SKIP,ENABLE}_TRANSFER_FUNCTION_BIT_KHR flag usage.
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Note
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No range compression or Y′CBCR model conversion is performed by VK_RESOLVE_MODE_EXTERNAL_FORMAT_DOWNSAMPLE_BIT_ANDROID; applications have to do these conversions themselves. Value outputs are expected to match those that would be read through a Y′CBCR sampler using VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY. The color space that the values should be in is defined by the platform and is not exposed via Vulkan. |
Document Notes
For more information, see the Vulkan Specification.
This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.