## C Specification

The set of image layouts consists of:

typedef enum VkImageLayout {
VK_IMAGE_LAYOUT_UNDEFINED = 0,
VK_IMAGE_LAYOUT_GENERAL = 1,
VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL = 2,
VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL = 3,
VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL = 6,
VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL = 7,
VK_IMAGE_LAYOUT_PREINITIALIZED = 8,
VK_IMAGE_LAYOUT_PRESENT_SRC_KHR = 1000001002,
VK_IMAGE_LAYOUT_SHARED_PRESENT_KHR = 1000111000,
VK_IMAGE_LAYOUT_FRAGMENT_DENSITY_MAP_OPTIMAL_EXT = 1000218000,
VK_IMAGE_LAYOUT_MAX_ENUM = 0x7FFFFFFF
} VkImageLayout;

## Description

The type(s) of device access supported by each layout are:

• VK_IMAGE_LAYOUT_UNDEFINED does not support device access. This layout must only be used as the initialLayout member of VkImageCreateInfo or VkAttachmentDescription, or as the oldLayout in an image transition. When transitioning out of this layout, the contents of the memory are not guaranteed to be preserved.

• VK_IMAGE_LAYOUT_PREINITIALIZED does not support device access. This layout must only be used as the initialLayout member of VkImageCreateInfo or VkAttachmentDescription, or as the oldLayout in an image transition. When transitioning out of this layout, the contents of the memory are preserved. This layout is intended to be used as the initial layout for an image whose contents are written by the host, and hence the data can be written to memory immediately, without first executing a layout transition. Currently, VK_IMAGE_LAYOUT_PREINITIALIZED is only useful with linear images because there is not a standard layout defined for VK_IMAGE_TILING_OPTIMAL images.

• VK_IMAGE_LAYOUT_GENERAL supports all types of device access.

• VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL must only be used as a color or resolve attachment in a VkFramebuffer. This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT usage bit enabled.

• VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL must only be used as a depth/stencil or depth/stencil resolve attachment in a VkFramebuffer. This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT usage bit enabled.

• VK_IMAGE_LAYOUT_DEPTH_STENCIL_READ_ONLY_OPTIMAL must only be used as a read-only depth/stencil attachment in a VkFramebuffer and/or as a read-only image in a shader (which can be read as a sampled image, combined image/sampler and/or input attachment). This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT usage bit enabled. Only image views created with a usage value including VK_IMAGE_USAGE_SAMPLED_BIT can be used as a sampled image or combined image/sampler in a shader. Similarly, only image views created with a usage value including VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT can be used as input attachments.

• VK_IMAGE_LAYOUT_DEPTH_READ_ONLY_STENCIL_ATTACHMENT_OPTIMAL: must only be used as a depth/stencil attachment in a VkFramebuffer, where the depth aspect is read-only, and/or as a read-only image in a shader (which can be read as a sampled image, combined image/sampler and/or input attachment) where only the depth aspect is accessed. This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT usage bit enabled. Only image views created with a usage value including VK_IMAGE_USAGE_SAMPLED_BIT can be used as a sampled image or combined image/sampler in a shader. Similarly, only image views created with a usage value including VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT can be used as input attachments.

• VK_IMAGE_LAYOUT_DEPTH_ATTACHMENT_STENCIL_READ_ONLY_OPTIMAL: must only be used as a depth/stencil attachment in a VkFramebuffer, where the stencil aspect is read-only, and/or as a read-only image in a shader (which can be read as a sampled image, combined image/sampler and/or input attachment) where only the stencil aspect is accessed. This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT usage bit enabled. Only image views created with a usage value including VK_IMAGE_USAGE_SAMPLED_BIT can be used as a sampled image or combined image/sampler in a shader. Similarly, only image views created with a usage value including VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT can be used as input attachments.

• VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL must only be used as a read-only image in a shader (which can be read as a sampled image, combined image/sampler and/or input attachment). This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_SAMPLED_BIT or VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT usage bit enabled.

• VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL must only be used as a source image of a transfer command (see the definition of VK_PIPELINE_STAGE_TRANSFER_BIT). This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_TRANSFER_SRC_BIT usage bit enabled.

• VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL must only be used as a destination image of a transfer command. This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_TRANSFER_DST_BIT usage bit enabled.

• VK_IMAGE_LAYOUT_PRESENT_SRC_KHR must only be used for presenting a presentable image for display. A swapchain’s image must be transitioned to this layout before calling vkQueuePresentKHR, and must be transitioned away from this layout after calling vkAcquireNextImageKHR.

• VK_IMAGE_LAYOUT_SHARED_PRESENT_KHR is valid only for shared presentable images, and must be used for any usage the image supports.

• VK_IMAGE_LAYOUT_SHADING_RATE_OPTIMAL_NV must only be used as a read-only shading-rate-image. This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_SHADING_RATE_IMAGE_BIT_NV usage bit enabled.

• VK_IMAGE_LAYOUT_FRAGMENT_DENSITY_MAP_OPTIMAL_EXT must only be used as a fragment density map attachment in a VkRenderPass. This layout is valid only for image subresources of images created with the VK_IMAGE_USAGE_FRAGMENT_DENSITY_MAP_BIT_EXT usage bit enabled.

The layout of each image subresource is not a state of the image subresource itself, but is rather a property of how the data in memory is organized, and thus for each mechanism of accessing an image in the API the application must specify a parameter or structure member that indicates which image layout the image subresource(s) are considered to be in when the image will be accessed. For transfer commands, this is a parameter to the command (see https://www.khronos.org/registry/vulkan/specs/1.1-extensions/html/vkspec.html#clears and https://www.khronos.org/registry/vulkan/specs/1.1-extensions/html/vkspec.html#copies). For use as a framebuffer attachment, this is a member in the substructures of the VkRenderPassCreateInfo (see Render Pass). For use in a descriptor set, this is a member in the VkDescriptorImageInfo structure (see https://www.khronos.org/registry/vulkan/specs/1.1-extensions/html/vkspec.html#descriptorsets-updates).