VkSubpassDescription

The VkSubpassDescription structure is defined as:

typedef struct VkSubpassDescription {
    VkSubpassDescriptionFlags flags;
    VkPipelineBindPoint pipelineBindPoint;
    uint32_t inputAttachmentCount;
    const VkAttachmentReference* pInputAttachments;
    uint32_t colorAttachmentCount;
    const VkAttachmentReference* pColorAttachments;
    const VkAttachmentReference* pResolveAttachments;
    const VkAttachmentReference* pDepthStencilAttachment;
    uint32_t preserveAttachmentCount;
    const uint32_t* pPreserveAttachments;
} VkSubpassDescription;

flags is a bitmask of VkSubpassDescriptionFlagBits specifying usage of the subpass.
pipelineBindPoint is a VkPipelineBindPoint value specifying the pipeline type supported for this subpass.
inputAttachmentCount is the number of input attachments.
pInputAttachments is a pointer to an array of VkAttachmentReference 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 VkAttachmentReference structures defining the color attachments for this subpass and their layouts.
pResolveAttachments is NULL or a pointer to an array of colorAttachmentCount VkAttachmentReference structures defining the resolve attachments for this subpass and their layouts.
pDepthStencilAttachment is a pointer to a VkAttachmentReference 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.

Each element of the pInputAttachments array corresponds to an input attachment index in a fragment shader, i.e. if a shader declares an image variable decorated with a InputAttachmentIndex value of X, then it uses the attachment provided in pInputAttachments[X]. Input attachments must also be bound to the pipeline in a descriptor set. If the attachment member of any element of pInputAttachments is VK_ATTACHMENT_UNUSED, the application must not read from the corresponding input attachment index. Fragment shaders can use subpass input variables to access the contents of an input attachment at the fragment’s (x, y, layer) framebuffer coordinates. Input attachments must not be used by any subpasses within a render pass that enables render pass transform.

Each element of the pColorAttachments array corresponds to an output location in the shader, i.e. if the shader declares an output variable decorated with a Location value of X, then it uses the attachment provided in pColorAttachments[X]. If the attachment member of any element of pColorAttachments is VK_ATTACHMENT_UNUSED, or if Color Write Enable has been disabled for the corresponding attachment index, then writes to the corresponding location by a fragment shader are discarded.

If flags does not include VK_SUBPASS_DESCRIPTION_SHADER_RESOLVE_BIT_QCOM, and if pResolveAttachments is not NULL, each of its elements corresponds to a color attachment (the element in pColorAttachments at the same index), and a multisample resolve operation is defined for each attachment unless the resolve attachment index is VK_ATTACHMENT_UNUSED.

Similarly, if flags does not include VK_SUBPASS_DESCRIPTION_SHADER_RESOLVE_BIT_QCOM, and VkSubpassDescriptionDepthStencilResolve::pDepthStencilResolveAttachment is not NULL and does not have the value VK_ATTACHMENT_UNUSED, it corresponds to the depth/stencil attachment in pDepthStencilAttachment, and multisample resolve operation for depth and stencil are defined by VkSubpassDescriptionDepthStencilResolve::depthResolveMode and VkSubpassDescriptionDepthStencilResolve::stencilResolveMode, respectively. If VkSubpassDescriptionDepthStencilResolve::depthResolveMode is VK_RESOLVE_MODE_NONE or the pDepthStencilResolveAttachment does not have a depth aspect, no resolve operation is performed for the depth attachment. If VkSubpassDescriptionDepthStencilResolve::stencilResolveMode is VK_RESOLVE_MODE_NONE or the pDepthStencilResolveAttachment does not have a stencil aspect, no resolve operation is performed for the stencil attachment.

If the image subresource range referenced by the depth/stencil attachment is created with VK_IMAGE_CREATE_SAMPLE_LOCATIONS_COMPATIBLE_DEPTH_BIT_EXT, then the multisample resolve operation uses the sample locations state specified in the sampleLocationsInfo member of the element of the VkRenderPassSampleLocationsBeginInfoEXT::pPostSubpassSampleLocations for the subpass.

If pDepthStencilAttachment is NULL, or if its attachment index is VK_ATTACHMENT_UNUSED, it indicates that no depth/stencil attachment will be used in the subpass.

The contents of an attachment within the render area become undefined: at the start of a subpass S if all of the following conditions are true:

The attachment is used as a color, depth/stencil, or resolve attachment in any subpass in the render pass.
There is a subpass S₁ that uses or preserves the attachment, and a subpass dependency from S₁ to S.
The attachment is not used or preserved in subpass S.

In addition, the contents of an attachment within the render area become undefined: at the start of a subpass S if all of the following conditions are true:

VK_SUBPASS_DESCRIPTION_SHADER_RESOLVE_BIT_QCOM is set.
The attachment is used as a color or depth/stencil in the subpass.

Once the contents of an attachment become undefined: in subpass S, they remain undefined: for subpasses in subpass dependency chains starting with subpass S until they are written again. However, they remain valid for subpasses in other subpass dependency chains starting with subpass S₁ if those subpasses use or preserve the attachment.

Valid Usage

VUID-VkSubpassDescription-attachment-06912

If the attachment member of an element of pInputAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL or VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL

VUID-VkSubpassDescription-attachment-06913

If the attachment member of an element of pColorAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL or VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL

VUID-VkSubpassDescription-attachment-06914

If the attachment member of an element of pResolveAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL or VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL

VUID-VkSubpassDescription-attachment-06915

If the attachment member of pDepthStencilAttachment is not VK_ATTACHMENT_UNUSED, ts layout member must not be VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL or VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL

VUID-VkSubpassDescription-attachment-06916

If the attachment member of an element of pColorAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_DEPTH_ATTACHMENT_STENCIL_READ_ONLY_OPTIMAL or VK_IMAGE_LAYOUT_DEPTH_READ_ONLY_STENCIL_ATTACHMENT_OPTIMAL

VUID-VkSubpassDescription-attachment-06917

If the attachment member of an element of pResolveAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_DEPTH_ATTACHMENT_STENCIL_READ_ONLY_OPTIMAL or VK_IMAGE_LAYOUT_DEPTH_READ_ONLY_STENCIL_ATTACHMENT_OPTIMAL

VUID-VkSubpassDescription-attachment-06918

If the attachment member of an element of pInputAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_DEPTH_ATTACHMENT_OPTIMAL or VK_IMAGE_LAYOUT_STENCIL_ATTACHMENT_OPTIMAL

VUID-VkSubpassDescription-attachment-06919

If the attachment member of an element of pColorAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_DEPTH_ATTACHMENT_OPTIMAL, VK_IMAGE_LAYOUT_DEPTH_READ_ONLY_OPTIMAL, VK_IMAGE_LAYOUT_STENCIL_ATTACHMENT_OPTIMAL, or VK_IMAGE_LAYOUT_STENCIL_READ_ONLY_OPTIMAL

VUID-VkSubpassDescription-attachment-06920

If the attachment member of an element of pResolveAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_DEPTH_ATTACHMENT_OPTIMAL, VK_IMAGE_LAYOUT_DEPTH_READ_ONLY_OPTIMAL, VK_IMAGE_LAYOUT_STENCIL_ATTACHMENT_OPTIMAL, or VK_IMAGE_LAYOUT_STENCIL_READ_ONLY_OPTIMAL

VUID-VkSubpassDescription-attachment-06921

If the attachment member of an element of pInputAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_ATTACHMENT_OPTIMAL_KHR

VUID-VkSubpassDescription-attachment-06922

If the attachment member of an element of pColorAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_READ_ONLY_OPTIMAL_KHR

VUID-VkSubpassDescription-attachment-06923

If the attachment member of an element of pResolveAttachments is not VK_ATTACHMENT_UNUSED, its layout member must not be VK_IMAGE_LAYOUT_READ_ONLY_OPTIMAL_KHR

VUID-VkSubpassDescription-pipelineBindPoint-04952

pipelineBindPoint must be VK_PIPELINE_BIND_POINT_GRAPHICS or VK_PIPELINE_BIND_POINT_SUBPASS_SHADING_HUAWEI

VUID-VkSubpassDescription-colorAttachmentCount-00845

colorAttachmentCount must be less than or equal to VkPhysicalDeviceLimits::maxColorAttachments

VUID-VkSubpassDescription-loadOp-00846

If the first use of an attachment in this render pass is as an input attachment, and the attachment is not also used as a color or depth/stencil attachment in the same subpass, then loadOp must not be VK_ATTACHMENT_LOAD_OP_CLEAR

VUID-VkSubpassDescription-pResolveAttachments-00847

If pResolveAttachments is not NULL, for each resolve attachment that is not VK_ATTACHMENT_UNUSED, the corresponding color attachment must not be VK_ATTACHMENT_UNUSED

VUID-VkSubpassDescription-pResolveAttachments-00848

If pResolveAttachments is not NULL, for each resolve attachment that is not VK_ATTACHMENT_UNUSED, the corresponding color attachment must not have a sample count of VK_SAMPLE_COUNT_1_BIT

VUID-VkSubpassDescription-pResolveAttachments-00849

If pResolveAttachments is not NULL, each resolve attachment that is not VK_ATTACHMENT_UNUSED must have a sample count of VK_SAMPLE_COUNT_1_BIT

VUID-VkSubpassDescription-pResolveAttachments-00850

If pResolveAttachments is not NULL, each resolve attachment that is not VK_ATTACHMENT_UNUSED must have the same VkFormat as its corresponding color attachment

VUID-VkSubpassDescription-pColorAttachments-09430

All attachments in pColorAttachments that are not VK_ATTACHMENT_UNUSED must have the same sample count

VUID-VkSubpassDescription-pInputAttachments-02647

All attachments in pInputAttachments that are not VK_ATTACHMENT_UNUSED must have image formats whose potential format features contain at least VK_FORMAT_FEATURE_COLOR_ATTACHMENT_BIT or VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT

VUID-VkSubpassDescription-pColorAttachments-02648

All attachments in pColorAttachments that are not VK_ATTACHMENT_UNUSED must have image formats whose potential format features contain VK_FORMAT_FEATURE_COLOR_ATTACHMENT_BIT

VUID-VkSubpassDescription-pResolveAttachments-02649

All attachments in pResolveAttachments that are not VK_ATTACHMENT_UNUSED must have image formats whose potential format features contain VK_FORMAT_FEATURE_COLOR_ATTACHMENT_BIT

VUID-VkSubpassDescription-pDepthStencilAttachment-02650

If pDepthStencilAttachment is not NULL and the attachment is not VK_ATTACHMENT_UNUSED then it must have an image format whose potential format features contain VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT

VUID-VkSubpassDescription-linearColorAttachment-06496

If the linearColorAttachment feature is enabled and the image is created with VK_IMAGE_TILING_LINEAR, all attachments in pInputAttachments that are not VK_ATTACHMENT_UNUSED must have image formats whose potential format features must contain VK_FORMAT_FEATURE_2_LINEAR_COLOR_ATTACHMENT_BIT_NV

VUID-VkSubpassDescription-linearColorAttachment-06497

If the linearColorAttachment feature is enabled and the image is created with VK_IMAGE_TILING_LINEAR, all attachments in pColorAttachments that are not VK_ATTACHMENT_UNUSED must have image formats whose potential format features must contain VK_FORMAT_FEATURE_2_LINEAR_COLOR_ATTACHMENT_BIT_NV

VUID-VkSubpassDescription-linearColorAttachment-06498

If the linearColorAttachment feature is enabled and the image is created with VK_IMAGE_TILING_LINEAR, all attachments in pResolveAttachments that are not VK_ATTACHMENT_UNUSED must have image formats whose potential format features must contain VK_FORMAT_FEATURE_2_LINEAR_COLOR_ATTACHMENT_BIT_NV

VUID-VkSubpassDescription-None-09431

If either of the following is enabled:- The VK_AMD_mixed_attachment_samples extension

The VK_NV_framebuffer_mixed_samples extension

all attachments in pColorAttachments that are not VK_ATTACHMENT_UNUSED must have a sample count that is smaller than or equal to the sample count of pDepthStencilAttachment if it is not VK_ATTACHMENT_UNUSED

VUID-VkSubpassDescription-pDepthStencilAttachment-01418

If pDepthStencilAttachment is not VK_ATTACHMENT_UNUSED and any attachments in pColorAttachments are not VK_ATTACHMENT_UNUSED, they must have the same sample count , if none of the following are enabled:- The VK_AMD_mixed_attachment_samples extension

The VK_NV_framebuffer_mixed_samples extension ::

VUID-VkSubpassDescription-attachment-00853

Each element of pPreserveAttachments must not be VK_ATTACHMENT_UNUSED

VUID-VkSubpassDescription-pPreserveAttachments-00854

Each element of pPreserveAttachments must not also be an element of any other member of the subpass description

VUID-VkSubpassDescription-layout-02519

If any attachment is used by more than one VkAttachmentReference member, then each use must use the same layout

VUID-VkSubpassDescription-flags-00856

If flags includes VK_SUBPASS_DESCRIPTION_PER_VIEW_POSITION_X_ONLY_BIT_NVX, it must also include VK_SUBPASS_DESCRIPTION_PER_VIEW_ATTRIBUTES_BIT_NVX

VUID-VkSubpassDescription-flags-03341

If flags includes VK_SUBPASS_DESCRIPTION_SHADER_RESOLVE_BIT_QCOM, and if pResolveAttachments is not NULL, then each resolve attachment must be VK_ATTACHMENT_UNUSED

VUID-VkSubpassDescription-flags-03343

If flags includes VK_SUBPASS_DESCRIPTION_SHADER_RESOLVE_BIT_QCOM, then the subpass must be the last subpass in a subpass dependency chain

VUID-VkSubpassDescription-pInputAttachments-02868

If the render pass is created with VK_RENDER_PASS_CREATE_TRANSFORM_BIT_QCOM each of the elements of pInputAttachments must be VK_ATTACHMENT_UNUSED

VUID-VkSubpassDescription-pDepthStencilAttachment-04438

pDepthStencilAttachment and pColorAttachments must not contain references to the same attachment

VkSubpassDescription

Valid Usage

Valid Usage (Implicit)