VkResolveModeFlagBits

Multisample values in a multisample attachment are combined according to the resolve mode used:

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,
} VkResolveModeFlagBits;

or the equivalent

#define VkResolveModeFlagBitsKHR VkResolveModeFlagBits

• VK_RESOLVE_MODE_NONE specifies that no resolve operation is done.
• VK_RESOLVE_MODE_SAMPLE_ZERO_BIT specifies that result of the resolve operation is equal to the value of sample 0.
• VK_RESOLVE_MODE_AVERAGE_BIT specifies that result of the resolve operation is the average of the sample values.
• 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.
• VK_RESOLVE_MODE_EXTERNAL_FORMAT_DOWNSAMPLE_ANDROID specifies that rather than a multisample resolve, a single sampled color attachment will be downsampled into a Y′C_BC_R 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, C_B, and C_R 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.

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.