VkRenderPassSampleLocationsBeginInfoEXT

The image layout of the depth aspect of a depth/stencil attachment referring to an image created with VK_IMAGE_CREATE_SAMPLE_LOCATIONS_COMPATIBLE_DEPTH_BIT_EXT is dependent on the last sample locations used to render to the image subresource, thus preserving the contents of such depth/stencil attachments across subpass boundaries requires the application to specify these sample locations whenever a layout transition of the attachment may occur. This information can be provided by adding a VkRenderPassSampleLocationsBeginInfoEXT structure to the pNext chain of VkRenderPassBeginInfo.

The VkRenderPassSampleLocationsBeginInfoEXT structure is defined as:

typedef struct VkRenderPassSampleLocationsBeginInfoEXT {
    VkStructureType sType;
    const void* pNext;
    uint32_t attachmentInitialSampleLocationsCount;
    const VkAttachmentSampleLocationsEXT* pAttachmentInitialSampleLocations;
    uint32_t postSubpassSampleLocationsCount;
    const VkSubpassSampleLocationsEXT* pPostSubpassSampleLocations;
} VkRenderPassSampleLocationsBeginInfoEXT;

• sType is a VkStructureType value identifying this structure.
• pNext is NULL or a pointer to a structure extending this structure.
• attachmentInitialSampleLocationsCount is the number of elements in the pAttachmentInitialSampleLocations array.
• pAttachmentInitialSampleLocations is a pointer to an array of attachmentInitialSampleLocationsCount
  VkAttachmentSampleLocationsEXT structures specifying the attachment indices and their corresponding sample location state. Each element of pAttachmentInitialSampleLocations can specify the sample location state to use in the automatic layout transition performed to transition a depth/stencil attachment from the initial layout of the attachment to the image layout specified for the attachment in the first subpass using it.
• postSubpassSampleLocationsCount is the number of elements in the pPostSubpassSampleLocations array.
• pPostSubpassSampleLocations is a pointer to an array of postSubpassSampleLocationsCount VkSubpassSampleLocationsEXT structures specifying the subpass indices and their corresponding sample location state. Each element of pPostSubpassSampleLocations can specify the sample location state to use in the automatic layout transition performed to transition the depth/stencil attachment used by the specified subpass to the image layout specified in a dependent subpass or to the final layout of the attachment in case the specified subpass is the last subpass using that attachment. In addition, if VkPhysicalDeviceSampleLocationsPropertiesEXT::variableSampleLocations is VK_FALSE, each element of pPostSubpassSampleLocationsmust specify the sample location state that matches the sample locations used by all pipelines that will be bound to a command buffer during the specified subpass. If variableSampleLocations is VK_TRUE, the sample locations used for rasterization do not depend on pPostSubpassSampleLocations.