VkSubpassDescription2

The VkSubpassDescription2 structure is defined as:

typedef struct VkSubpassDescription2 {
    VkStructureType sType;
    const void* pNext;
    VkSubpassDescriptionFlags flags;
    VkPipelineBindPoint pipelineBindPoint;
    uint32_t viewMask;
    uint32_t inputAttachmentCount;
    const VkAttachmentReference2* pInputAttachments;
    uint32_t colorAttachmentCount;
    const VkAttachmentReference2* pColorAttachments;
    const VkAttachmentReference2* pResolveAttachments;
    const VkAttachmentReference2* pDepthStencilAttachment;
    uint32_t preserveAttachmentCount;
    const uint32_t* pPreserveAttachments;
} VkSubpassDescription2;

or the equivalent

typedef VkSubpassDescription2 VkSubpassDescription2KHR;

• 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 VkSubpassDescriptionFlagBits specifying usage of the subpass.
• pipelineBindPoint is a VkPipelineBindPoint value specifying the pipeline type supported for this subpass.
• viewMask is a bitfield of view indices describing which views rendering is broadcast to in this subpass, when multiview is enabled.
• inputAttachmentCount is the number of input attachments.
• pInputAttachments is a pointer to an array of VkAttachmentReference2 structures defining the input attachments for this subpass and their layouts.
• colorAttachmentCount is the number of color attachments.
• pColorAttachments is a pointer to an array of colorAttachmentCount VkAttachmentReference2 structures defining the color attachments for this subpass and their layouts.
• pResolveAttachments is NULL or a pointer to an array of colorAttachmentCount VkAttachmentReference2 structures defining the resolve attachments for this subpass and their layouts.
• pDepthStencilAttachment is a pointer to a VkAttachmentReference2 structure specifying the depth/stencil attachment for this subpass and its layout.
• preserveAttachmentCount is the number of preserved attachments.
• pPreserveAttachments is a pointer to an array of preserveAttachmentCount render pass attachment indices identifying attachments that are not used by this subpass, but whose contents must be preserved throughout the subpass.

Parameters defined by this structure with the same name as those in VkSubpassDescription have the identical effect to those parameters.

viewMask has the same effect for the described subpass as VkRenderPassMultiviewCreateInfo::pViewMasks has on each corresponding subpass.

If a VkFragmentShadingRateAttachmentInfoKHR structure is included in the pNext chain, pFragmentShadingRateAttachment is not NULL, and its attachment member is not VK_ATTACHMENT_UNUSED, the identified attachment defines a fragment shading rate attachment for that subpass.

If any element of pResolveAttachments is an image specified with an VkExternalFormatANDROID, values in the corresponding color attachment will be resolved to the resolve attachment in the same manner as specified for VK_RESOLVE_MODE_EXTERNAL_FORMAT_DOWNSAMPLE_ANDROID.

If the nullColorAttachmentWithExternalFormatResolve limit is VK_TRUE, values in the color attachment will be loaded from the resolve attachment at the start of rendering, and may also be reloaded any time after a resolve occurs or the resolve attachment is written to; if this occurs it must happen-before any writes to the color attachment are performed which happen-after the resolve that triggers this. If any color component in the external format is subsampled, values will be read from the nearest sample in the image when they are loaded. If the color attachment is also used as an input attachment, the same behavior applies.

Setting the color attachment to VK_ATTACHMENT_UNUSED when an external resolve attachment is used and the nullColorAttachmentWithExternalFormatResolve limit is VK_TRUE will not result in color attachment writes to be discarded for that attachment.

When nullColorAttachmentWithExternalFormatResolve is VK_TRUE, the color output from the subpass can still be read via an input attachment; but the application cannot bind an image view for the color attachment as there is no such image view bound. Instead to access the data as an input attachment applications can use the resolve attachment in its place - using the resolve attachment image for the descriptor, and setting the corresponding element of pInputAttachments to the index of the resolve attachment.

Loads or input attachment reads from the resolve attachment are performed as if using a VkSamplerYcbcrConversionCreateInfo with the following parameters:

where properties is equal to VkPhysicalDeviceExternalFormatResolvePropertiesANDROID returned by the device and forceExplicitReconstruction is effectively ignored as the VK_SAMPLER_YCBCR_MODEL_CONVERSION_RGB_IDENTITY model is used. The applied swizzle is the same effective swizzle that would be applied by the VK_SAMPLER_YCBCR_MODEL_CONVERSION_YCBCR_IDENTITY model, but no range expansion is applied.