19. Drawing Commands

Drawing commands (commands with Draw in the name) provoke work in a graphics pipeline. Drawing commands are recorded into a command buffer and when executed by a queue, will produce work which executes according to the bound graphics pipeline. A graphics pipeline must be bound to a command buffer before any drawing commands are recorded in that command buffer.

Each draw is made up of zero or more vertices and zero or more instances, which are processed by the device and result in the assembly of primitives. Primitives are assembled according to the pInputAssemblyState member of the VkGraphicsPipelineCreateInfo structure, which is of type VkPipelineInputAssemblyStateCreateInfo:

typedef struct VkPipelineInputAssemblyStateCreateInfo {
    VkStructureType                            sType;
    const void*                                pNext;
    VkPipelineInputAssemblyStateCreateFlags    flags;
    VkPrimitiveTopology                        topology;
    VkBool32                                   primitiveRestartEnable;
} VkPipelineInputAssemblyStateCreateInfo;
  • sType is the type of this structure.

  • pNext is NULL or a pointer to an extension-specific structure.

  • flags is reserved for future use.

  • topology is a VkPrimitiveTopology defining the primitive topology, as described below.

  • primitiveRestartEnable controls whether a special vertex index value is treated as restarting the assembly of primitives. This enable only applies to indexed draws (vkCmdDrawIndexed and vkCmdDrawIndexedIndirect), and the special index value is either 0xFFFFFFFF when the indexType parameter of vkCmdBindIndexBuffer is equal to VK_INDEX_TYPE_UINT32, or 0xFFFF when indexType is equal to VK_INDEX_TYPE_UINT16. Primitive restart is not allowed for “list” topologies.

Restarting the assembly of primitives discards the most recent index values if those elements formed an incomplete primitive, and restarts the primitive assembly using the subsequent indices, but only assembling the immediately following element through the end of the originally specified elements. The primitive restart index value comparison is performed before adding the vertexOffset value to the index value.

Valid Usage
  • If topology is VK_PRIMITIVE_TOPOLOGY_POINT_LIST, VK_PRIMITIVE_TOPOLOGY_LINE_LIST, VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY, VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY or VK_PRIMITIVE_TOPOLOGY_PATCH_LIST, primitiveRestartEnable must be VK_FALSE

  • If the geometry shaders feature is not enabled, topology must not be any of VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY, VK_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY, VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY or VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY

  • If the tessellation shaders feature is not enabled, topology must not be VK_PRIMITIVE_TOPOLOGY_PATCH_LIST

Valid Usage (Implicit)
  • sType must be VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO

  • pNext must be NULL

  • flags must be 0

  • topology must be a valid VkPrimitiveTopology value

typedef VkFlags VkPipelineInputAssemblyStateCreateFlags;

VkPipelineInputAssemblyStateCreateFlags is a bitmask type for setting a mask, but is currently reserved for future use.

19.1. Primitive Topologies

Primitive topology determines how consecutive vertices are organized into primitives, and determines the type of primitive that is used at the beginning of the graphics pipeline. The effective topology for later stages of the pipeline is altered by tessellation or geometry shading (if either is in use) and depends on the execution modes of those shaders.

The primitive topologies defined by VkPrimitiveTopology are:

typedef enum VkPrimitiveTopology {
    VK_PRIMITIVE_TOPOLOGY_POINT_LIST = 0,
    VK_PRIMITIVE_TOPOLOGY_LINE_LIST = 1,
    VK_PRIMITIVE_TOPOLOGY_LINE_STRIP = 2,
    VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST = 3,
    VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP = 4,
    VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN = 5,
    VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY = 6,
    VK_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY = 7,
    VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY = 8,
    VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY = 9,
    VK_PRIMITIVE_TOPOLOGY_PATCH_LIST = 10,
    VK_PRIMITIVE_TOPOLOGY_MAX_ENUM = 0x7FFFFFFF
} VkPrimitiveTopology;

Each primitive topology, and its construction from a list of vertices, is described in detail below with a supporting diagram, according to the following key:

image/svg+xml

Vertex

A point in 3-dimensional space. Positions chosen within the diagrams are arbitrary and for illustration only.

image/svg+xml 5

Vertex Number

Sequence position of a vertex within the provided vertex data.

image/svg+xml

Provoking Vertex

Provoking vertex within the main primitive. The arrow points along an edge of the relevant primitive, following winding order. Used in flat shading.

image/svg+xml

Primitive Edge

An edge connecting the points of a main primitive.

image/svg+xml

Adjacency Edge

Points connected by these lines do not contribute to a main primitive, and are only accessible in a geometry shader.

image/svg+xml

Winding Order

The relative order in which vertices are defined within a primitive, used in the facing determination. This ordering has no specific start or end point.

The diagrams are supported with mathematical definitions where the vertices (v) and primitives (p) are numbered starting from 0; v0 is the first vertex in the provided data and p0 is the first primitive in the set of primitives defined by the vertices and topology.

19.1.1. Point Lists

When the topology is VK_PRIMITIVE_TOPOLOGY_POINT_LIST, each consecutive vertex defines a single point primitive, according to the equation:

pi = {vi}

As there is only one vertex, that vertex is the provoking vertex. The number of primitives generated is equal to vertexCount.

image/svg+xml 0 4 2 1 3

19.1.2. Line Lists

When the topology is VK_PRIMITIVE_TOPOLOGY_LINE_LIST, each consecutive pair of vertices defines a single line primitive, according to the equation:

pi = {v2i, v2i+1}

The provoking vertex for pi is v2i. The number of primitives generated is equal to vertexCount/2⌋.

image/svg+xml 0 2 1 3

19.1.3. Line Strips

When the topology is VK_PRIMITIVE_TOPOLOGY_LINE_STRIP, one line primitive is defined by each vertex and the following vertex, according to the equation:

pi = {vi, vi+1}

The provoking vertex for pi is vi. The number of primitives generated is equal to max(0,vertexCount-1).

image/svg+xml 0 2 1 3

19.1.4. Triangle Lists

When the topology is VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, each consecutive set of three vertices defines a single triangle primitive, according to the equation:

pi = {v3i, v3i+1, v3i+2}

The provoking vertex for pi is v3i. The number of primitives generated is equal to vertexCount/3⌋.

image/svg+xml 2 1 0 3 5 4

19.1.5. Triangle Strips

When the topology is VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP, one triangle primitive is defined by each vertex and the two vertices that follow it, according to the equation:

pi = {vi, vi+(1+i%2), vi+(2-i%2)}

The provoking vertex for pi is vi. The number of primitives generated is equal to max(0,vertexCount-2).

image/svg+xml 0 4 2 1 3
Note

The ordering of the vertices in each successive triangle is reversed, so that the winding order is consistent throughout the strip.

19.1.6. Triangle Fans

When the topology is VK_PRIMITIVE_TOPOLOGY_TRIANGLE_FAN, triangle primitives are defined around a shared common vertex, according to the equation:

pi = {vi+1, vi+2, v0}

The provoking vertex for pi is vi+1. The number of primitives generated is equal to max(0,vertexCount-2).

image/svg+xml 0 4 2 1 3

19.1.7. Line Lists With Adjacency

When the topology is VK_PRIMITIVE_TOPOLOGY_LINE_LIST_WITH_ADJACENCY, each consecutive set of four vertices defines a single line primitive with adjacency, according to the equation:

pi = {v4i, v4i+1, v4i+2,v4i+3}

A line primitive is described by the second and third vertices of the total primitive, with the remaining two vertices only accessible in a geometry shader.

The provoking vertex for pi is v4i+1. The number of primitives generated is equal to vertexCount/4⌋.

image/svg+xml 0 2 1 3 4 6 5 7

19.1.8. Line Strips With Adjacency

When the topology is VK_PRIMITIVE_TOPOLOGY_LINE_STRIP_WITH_ADJACENCY, one line primitive with adjacency is defined by each vertex and the following vertex, according to the equation:

pi = {vi, vi+1, vi+2, vi+3}

A line primitive is described by the second and third vertices of the total primitive, with the remaining two vertices only accessible in a geometry shader.

The provoking vertex for pi is vi+1. The number of primitives generated is equal to max(0,vertexCount-3).

image/svg+xml 0 2 1 3 4 5

19.1.9. Triangle Lists With Adjacency

When the topology is VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST_WITH_ADJACENCY, each consecutive set of six vertices defines a single triangle primitive with adjacency, according to the equations:

pi = {v6i, v6i+1, v6i+2, v6i+3, v6i+4, v6i+5}

A triangle primitive is described by the first, third, and fifth vertices of the total primitive, with the remaining three vertices only accessible in a geometry shader.

The provoking vertex for pi is v6i. The number of primitives generated is equal to vertexCount/6⌋.

image/svg+xml 0 4 2 1 5 3 6 8 10 11 7 9

19.1.10. Triangle Strips With Adjacency

When the topology is VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP_WITH_ADJACENCY, one triangle primitive with adjacency is defined by each vertex and the following 5 vertices.

The number of primitives generated, n, is equal to ⌊max(0, vertexCount - 4)/2⌋.

If n=1, the primitive is defined as:

p = {v0, v1, v2, v5, v4, v3}

If n>1, the total primitive consists of different vertices according to where it is in the strip:

pi = {v2i, v2i+1, v2i+2, v2i+6, v2i+4, v2i+3} when i=0

pi = {v2i, v2i+3, v2i+4, v2i+6, v2i+2, v2i-2} when i>0, i<n-1, and i%2=1

pi = {v2i, v2i-2, v2i+2, v2i+6, v2i+4, v2i+3} when i>0, i<n-1, and i%2=0

pi = {v2i, v2i+3, v2i+4, v2i+5, v2i+2, v2i-2} when i=n-1 and i%2=1

pi = {v2i, v2i-2, v2i+2, v2i+5, v2i+4, v2i+3} when i=n-1 and i%2=0

A triangle primitive is described by the first, third, and fifth vertices of the total primitive in all cases, with the remaining three vertices only accessible in a geometry shader.

Note

The ordering of the vertices in each successive triangle is altered so that the winding order is consistent throughout the strip.

The provoking vertex for pi is always v2i.

image/svg+xml 0 4 2 1 5 3 2 6 5 7 7 8 9 7 8 10 9 11 0 4 1 3 2 6 5 0 4 1 3 2 6 5 0 4 1 3

19.1.11. Patch Lists

When the topology is VK_PRIMITIVE_TOPOLOGY_PATCH_LIST, each consecutive set of m vertices defines a single patch primitive, according to the equation:

pi = {vmi, vmi+1, …​, vmi+(m-2), vmi+(m-1)}

where m is equal to VkPipelineTessellationStateCreateInfo::patchControlPoints.

Patch lists are never passed to vertex post-processing, and as such no provoking vertex is defined for patch primitives. The number of primitives generated is equal to vertexCount/m⌋.

The vertices comprising a patch have no implied geometry, and are used as inputs to tessellation shaders and the fixed-function tessellator to generate new point, line, or triangle primitives.

19.2. Primitive Order

Primitives generated by drawing commands progress through the stages of the graphics pipeline in primitive order. Primitive order is initially determined in the following way:

  1. Submission order determines the initial ordering

  2. For indirect draw commands, the order in which accessed instances of the VkDrawIndirectCommand are stored in buffer, from lower indirect buffer addresses to higher addresses.

  3. If a draw command includes multiple instances, the order in which instances are executed, from lower numbered instances to higher.

  4. The order in which primitives are specified by a draw command:

    • For non-indexed draws, from vertices with a lower numbered vertexIndex to a higher numbered vertexIndex.

    • For indexed draws, vertices sourced from a lower index buffer addresses to higher addresses.

Within this order implementations further sort primitives:

  1. If tessellation shading is active, by an implementation-dependent order of new primitives generated by tessellation.

  2. If geometry shading is active, by the order new primitives are generated by geometry shading.

  3. If the polygon mode is not VK_POLYGON_MODE_FILL, by an implementation-dependent ordering of the new primitives generated within the original primitive.

Primitive order is later used to define rasterization order, which determines the order in which fragments output results to a framebuffer.

19.3. Programmable Primitive Shading

Once primitives are assembled, they proceed to the vertex shading stage of the pipeline. If the draw includes multiple instances, then the set of primitives is sent to the vertex shading stage multiple times, once for each instance.

It is implementation-dependent whether vertex shading occurs on vertices that are discarded as part of incomplete primitives, but if it does occur then it operates as if they were vertices in complete primitives and such invocations can have side effects.

Vertex shading receives two per-vertex inputs from the primitive assembly stage - the vertexIndex and the instanceIndex. How these values are generated is defined below, with each command.

Drawing commands fall roughly into two categories:

To bind an index buffer to a command buffer, call:

void vkCmdBindIndexBuffer(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset,
    VkIndexType                                 indexType);
  • commandBuffer is the command buffer into which the command is recorded.

  • buffer is the buffer being bound.

  • offset is the starting offset in bytes within buffer used in index buffer address calculations.

  • indexType is a VkIndexType value specifying whether indices are treated as 16 bits or 32 bits.

Valid Usage
  • offset must be less than the size of buffer

  • The sum of offset and the address of the range of VkDeviceMemory object that is backing buffer, must be a multiple of the type indicated by indexType

  • buffer must have been created with the VK_BUFFER_USAGE_INDEX_BUFFER_BIT flag

  • If buffer is non-sparse then it must be bound completely and contiguously to a single VkDeviceMemory object

Valid Usage (Implicit)
  • commandBuffer must be a valid VkCommandBuffer handle

  • buffer must be a valid VkBuffer handle

  • indexType must be a valid VkIndexType value

  • commandBuffer must be in the recording state

  • The VkCommandPool that commandBuffer was allocated from must support graphics operations

  • Both of buffer, and commandBuffer must have been created, allocated, or retrieved from the same VkDevice

Host Synchronization
  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Pipeline Type

Primary
Secondary

Both

Graphics

Possible values of vkCmdBindIndexBuffer::indexType, specifying the size of indices, are:

typedef enum VkIndexType {
    VK_INDEX_TYPE_UINT16 = 0,
    VK_INDEX_TYPE_UINT32 = 1,
    VK_INDEX_TYPE_MAX_ENUM = 0x7FFFFFFF
} VkIndexType;
  • VK_INDEX_TYPE_UINT16 specifies that indices are 16-bit unsigned integer values.

  • VK_INDEX_TYPE_UINT32 specifies that indices are 32-bit unsigned integer values.

The parameters for each drawing command are specified directly in the command or read from buffer memory, depending on the command. Drawing commands that source their parameters from buffer memory are known as indirect drawing commands.

All drawing commands interact with the Robust Buffer Access feature.

To record a non-indexed draw, call:

void vkCmdDraw(
    VkCommandBuffer                             commandBuffer,
    uint32_t                                    vertexCount,
    uint32_t                                    instanceCount,
    uint32_t                                    firstVertex,
    uint32_t                                    firstInstance);
  • commandBuffer is the command buffer into which the command is recorded.

  • vertexCount is the number of vertices to draw.

  • instanceCount is the number of instances to draw.

  • firstVertex is the index of the first vertex to draw.

  • firstInstance is the instance ID of the first instance to draw.

When the command is executed, primitives are assembled using the current primitive topology and vertexCount consecutive vertex indices with the first vertexIndex value equal to firstVertex. The primitives are drawn instanceCount times with instanceIndex starting with firstInstance and increasing sequentially for each instance. The assembled primitives execute the bound graphics pipeline.

Valid Usage
  • If a VkImageView is sampled with VK_FILTER_LINEAR as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT

  • If a VkImageView is accessed using atomic operations as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT

  • For each set n that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a descriptor set must have been bound to n at the same pipeline bind point, with a VkPipelineLayout that is compatible for set n, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • For each push constant that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a push constant value must have been set for the same pipeline bind point, with a VkPipelineLayout that is compatible for push constants, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • Descriptors in each bound descriptor set, specified via vkCmdBindDescriptorSets, must be valid if they are statically used by the VkPipeline bound to the pipeline bind point used by this command

  • A valid pipeline must be bound to the pipeline bind point used by this command

  • If the VkPipeline object bound to the pipeline bind point used by this command requires any dynamic state, that state must have been set for commandBuffer

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used to sample from any VkImage with a VkImageView of the type VK_IMAGE_VIEW_TYPE_3D, VK_IMAGE_VIEW_TYPE_CUBE, VK_IMAGE_VIEW_TYPE_1D_ARRAY, VK_IMAGE_VIEW_TYPE_2D_ARRAY or VK_IMAGE_VIEW_TYPE_CUBE_ARRAY, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions with ImplicitLod, Dref or Proj in their name, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions that includes a LOD bias or any offset values, in any shader stage

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a uniform buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a storage buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If commandBuffer is an unprotected command buffer, any resource accessed by the VkPipeline object bound to the pipeline bind point used by this command must not be a protected resource

  • The current render pass must be compatible with the renderPass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • The subpass index of the current render pass must be equal to the subpass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • Every input attachment used by the current subpass must be bound to the pipeline via a descriptor set

  • Image subresources used as attachments in the current render pass must not be accessed in any way other than as an attachment by this command.

  • If the draw is recorded in a render pass instance with multiview enabled, the maximum instance index must be less than or equal to VkPhysicalDeviceMultiviewProperties::maxMultiviewInstanceIndex.

  • If commandBuffer is a protected command buffer, any resource written to by the VkPipeline object bound to the pipeline bind point used by this command must not be an unprotected resource

  • If commandBuffer is a protected command buffer, pipeline stages other than the framebuffer-space and compute stages in the VkPipeline object bound to the pipeline bind point must not write to any resource

  • All vertex input bindings accessed via vertex input variables declared in the vertex shader entry point’s interface must have valid buffers bound

  • For a given vertex buffer binding, any attribute data fetched must be entirely contained within the corresponding vertex buffer binding, as described in Vertex Input Description

Valid Usage (Implicit)
  • commandBuffer must be a valid VkCommandBuffer handle

  • commandBuffer must be in the recording state

  • The VkCommandPool that commandBuffer was allocated from must support graphics operations

  • This command must only be called inside of a render pass instance

Host Synchronization
  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Pipeline Type

Primary
Secondary

Inside

Graphics

Graphics

To record an indexed draw, call:

void vkCmdDrawIndexed(
    VkCommandBuffer                             commandBuffer,
    uint32_t                                    indexCount,
    uint32_t                                    instanceCount,
    uint32_t                                    firstIndex,
    int32_t                                     vertexOffset,
    uint32_t                                    firstInstance);
  • commandBuffer is the command buffer into which the command is recorded.

  • indexCount is the number of vertices to draw.

  • instanceCount is the number of instances to draw.

  • firstIndex is the base index within the index buffer.

  • vertexOffset is the value added to the vertex index before indexing into the vertex buffer.

  • firstInstance is the instance ID of the first instance to draw.

When the command is executed, primitives are assembled using the current primitive topology and indexCount vertices whose indices are retrieved from the index buffer. The index buffer is treated as an array of tightly packed unsigned integers of size defined by the vkCmdBindIndexBuffer::indexType parameter with which the buffer was bound.

The first vertex index is at an offset of firstIndex * indexSize + offset within the bound index buffer, where offset is the offset specified by vkCmdBindIndexBuffer and indexSize is the byte size of the type specified by indexType. Subsequent index values are retrieved from consecutive locations in the index buffer. Indices are first compared to the primitive restart value, then zero extended to 32 bits (if the indexType is VK_INDEX_TYPE_UINT16) and have vertexOffset added to them, before being supplied as the vertexIndex value.

The primitives are drawn instanceCount times with instanceIndex starting with firstInstance and increasing sequentially for each instance. The assembled primitives execute the bound graphics pipeline.

Valid Usage
  • If a VkImageView is sampled with VK_FILTER_LINEAR as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT

  • If a VkImageView is accessed using atomic operations as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT

  • For each set n that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a descriptor set must have been bound to n at the same pipeline bind point, with a VkPipelineLayout that is compatible for set n, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • For each push constant that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a push constant value must have been set for the same pipeline bind point, with a VkPipelineLayout that is compatible for push constants, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • Descriptors in each bound descriptor set, specified via vkCmdBindDescriptorSets, must be valid if they are statically used by the VkPipeline bound to the pipeline bind point used by this command

  • A valid pipeline must be bound to the pipeline bind point used by this command

  • If the VkPipeline object bound to the pipeline bind point used by this command requires any dynamic state, that state must have been set for commandBuffer

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used to sample from any VkImage with a VkImageView of the type VK_IMAGE_VIEW_TYPE_3D, VK_IMAGE_VIEW_TYPE_CUBE, VK_IMAGE_VIEW_TYPE_1D_ARRAY, VK_IMAGE_VIEW_TYPE_2D_ARRAY or VK_IMAGE_VIEW_TYPE_CUBE_ARRAY, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions with ImplicitLod, Dref or Proj in their name, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions that includes a LOD bias or any offset values, in any shader stage

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a uniform buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a storage buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If commandBuffer is an unprotected command buffer, any resource accessed by the VkPipeline object bound to the pipeline bind point used by this command must not be a protected resource

  • The current render pass must be compatible with the renderPass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • The subpass index of the current render pass must be equal to the subpass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • Every input attachment used by the current subpass must be bound to the pipeline via a descriptor set

  • Image subresources used as attachments in the current render pass must not be accessed in any way other than as an attachment by this command.

  • If the draw is recorded in a render pass instance with multiview enabled, the maximum instance index must be less than or equal to VkPhysicalDeviceMultiviewProperties::maxMultiviewInstanceIndex.

  • If commandBuffer is a protected command buffer, any resource written to by the VkPipeline object bound to the pipeline bind point used by this command must not be an unprotected resource

  • If commandBuffer is a protected command buffer, pipeline stages other than the framebuffer-space and compute stages in the VkPipeline object bound to the pipeline bind point must not write to any resource

  • All vertex input bindings accessed via vertex input variables declared in the vertex shader entry point’s interface must have valid buffers bound

  • For a given vertex buffer binding, any attribute data fetched must be entirely contained within the corresponding vertex buffer binding, as described in Vertex Input Description

  • (indexSize * (firstIndex + indexCount) + offset) must be less than or equal to the size of the bound index buffer, with indexSize being based on the type specified by indexType, where the index buffer, indexType, and offset are specified via vkCmdBindIndexBuffer

Valid Usage (Implicit)
  • commandBuffer must be a valid VkCommandBuffer handle

  • commandBuffer must be in the recording state

  • The VkCommandPool that commandBuffer was allocated from must support graphics operations

  • This command must only be called inside of a render pass instance

Host Synchronization
  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Pipeline Type

Primary
Secondary

Inside

Graphics

Graphics

To record a non-indexed indirect draw, call:

void vkCmdDrawIndirect(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset,
    uint32_t                                    drawCount,
    uint32_t                                    stride);
  • commandBuffer is the command buffer into which the command is recorded.

  • buffer is the buffer containing draw parameters.

  • offset is the byte offset into buffer where parameters begin.

  • drawCount is the number of draws to execute, and can be zero.

  • stride is the byte stride between successive sets of draw parameters.

vkCmdDrawIndirect behaves similarly to vkCmdDraw except that the parameters are read by the device from a buffer during execution. drawCount draws are executed by the command, with parameters taken from buffer starting at offset and increasing by stride bytes for each successive draw. The parameters of each draw are encoded in an array of VkDrawIndirectCommand structures. If drawCount is less than or equal to one, stride is ignored.

Valid Usage
  • If a VkImageView is sampled with VK_FILTER_LINEAR as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT

  • If a VkImageView is accessed using atomic operations as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT

  • For each set n that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a descriptor set must have been bound to n at the same pipeline bind point, with a VkPipelineLayout that is compatible for set n, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • For each push constant that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a push constant value must have been set for the same pipeline bind point, with a VkPipelineLayout that is compatible for push constants, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • Descriptors in each bound descriptor set, specified via vkCmdBindDescriptorSets, must be valid if they are statically used by the VkPipeline bound to the pipeline bind point used by this command

  • A valid pipeline must be bound to the pipeline bind point used by this command

  • If the VkPipeline object bound to the pipeline bind point used by this command requires any dynamic state, that state must have been set for commandBuffer

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used to sample from any VkImage with a VkImageView of the type VK_IMAGE_VIEW_TYPE_3D, VK_IMAGE_VIEW_TYPE_CUBE, VK_IMAGE_VIEW_TYPE_1D_ARRAY, VK_IMAGE_VIEW_TYPE_2D_ARRAY or VK_IMAGE_VIEW_TYPE_CUBE_ARRAY, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions with ImplicitLod, Dref or Proj in their name, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions that includes a LOD bias or any offset values, in any shader stage

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a uniform buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a storage buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If commandBuffer is an unprotected command buffer, any resource accessed by the VkPipeline object bound to the pipeline bind point used by this command must not be a protected resource

  • The current render pass must be compatible with the renderPass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • The subpass index of the current render pass must be equal to the subpass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • Every input attachment used by the current subpass must be bound to the pipeline via a descriptor set

  • Image subresources used as attachments in the current render pass must not be accessed in any way other than as an attachment by this command.

  • If the draw is recorded in a render pass instance with multiview enabled, the maximum instance index must be less than or equal to VkPhysicalDeviceMultiviewProperties::maxMultiviewInstanceIndex.

  • All vertex input bindings accessed via vertex input variables declared in the vertex shader entry point’s interface must have valid buffers bound

  • For a given vertex buffer binding, any attribute data fetched must be entirely contained within the corresponding vertex buffer binding, as described in Vertex Input Description

  • If buffer is non-sparse then it must be bound completely and contiguously to a single VkDeviceMemory object

  • buffer must have been created with the VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT bit set

  • offset must be a multiple of 4

  • commandBuffer must not be a protected command buffer

  • If the multi-draw indirect feature is not enabled, drawCount must be 0 or 1

  • drawCount must be less than or equal to VkPhysicalDeviceLimits::maxDrawIndirectCount

  • If the drawIndirectFirstInstance feature is not enabled, all the firstInstance members of the VkDrawIndirectCommand structures accessed by this command must be 0

  • If drawCount is greater than 1, stride must be a multiple of 4 and must be greater than or equal to sizeof(VkDrawIndirectCommand)

  • If drawCount is equal to 1, (offset + sizeof(VkDrawIndirectCommand)) must be less than or equal to the size of buffer

  • If drawCount is greater than 1, (stride × (drawCount - 1) + offset + sizeof(VkDrawIndirectCommand)) must be less than or equal to the size of buffer

Valid Usage (Implicit)
  • commandBuffer must be a valid VkCommandBuffer handle

  • buffer must be a valid VkBuffer handle

  • commandBuffer must be in the recording state

  • The VkCommandPool that commandBuffer was allocated from must support graphics operations

  • This command must only be called inside of a render pass instance

  • Both of buffer, and commandBuffer must have been created, allocated, or retrieved from the same VkDevice

Host Synchronization
  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Pipeline Type

Primary
Secondary

Inside

Graphics

Graphics

The VkDrawIndirectCommand structure is defined as:

typedef struct VkDrawIndirectCommand {
    uint32_t    vertexCount;
    uint32_t    instanceCount;
    uint32_t    firstVertex;
    uint32_t    firstInstance;
} VkDrawIndirectCommand;
  • vertexCount is the number of vertices to draw.

  • instanceCount is the number of instances to draw.

  • firstVertex is the index of the first vertex to draw.

  • firstInstance is the instance ID of the first instance to draw.

The members of VkDrawIndirectCommand have the same meaning as the similarly named parameters of vkCmdDraw.

Valid Usage
  • For a given vertex buffer binding, any attribute data fetched must be entirely contained within the corresponding vertex buffer binding, as described in Vertex Input Description

  • If the drawIndirectFirstInstance feature is not enabled, firstInstance must be 0

To record a non-indexed draw call with a draw call count sourced from a buffer, call:

void vkCmdDrawIndirectCountKHR(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset,
    VkBuffer                                    countBuffer,
    VkDeviceSize                                countBufferOffset,
    uint32_t                                    maxDrawCount,
    uint32_t                                    stride);
  • commandBuffer is the command buffer into which the command is recorded.

  • buffer is the buffer containing draw parameters.

  • offset is the byte offset into buffer where parameters begin.

  • countBuffer is the buffer containing the draw count.

  • countBufferOffset is the byte offset into countBuffer where the draw count begins.

  • maxDrawCount specifies the maximum number of draws that will be executed. The actual number of executed draw calls is the minimum of the count specified in countBuffer and maxDrawCount.

  • stride is the byte stride between successive sets of draw parameters.

vkCmdDrawIndirectCountKHR behaves similarly to vkCmdDrawIndirect except that the draw count is read by the device from a buffer during execution. The command will read an unsigned 32-bit integer from countBuffer located at countBufferOffset and use this as the draw count.

Valid Usage
  • If a VkImageView is sampled with VK_FILTER_LINEAR as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT

  • If a VkImageView is accessed using atomic operations as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT

  • For each set n that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a descriptor set must have been bound to n at the same pipeline bind point, with a VkPipelineLayout that is compatible for set n, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • For each push constant that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a push constant value must have been set for the same pipeline bind point, with a VkPipelineLayout that is compatible for push constants, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • Descriptors in each bound descriptor set, specified via vkCmdBindDescriptorSets, must be valid if they are statically used by the VkPipeline bound to the pipeline bind point used by this command

  • A valid pipeline must be bound to the pipeline bind point used by this command

  • If the VkPipeline object bound to the pipeline bind point used by this command requires any dynamic state, that state must have been set for commandBuffer

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used to sample from any VkImage with a VkImageView of the type VK_IMAGE_VIEW_TYPE_3D, VK_IMAGE_VIEW_TYPE_CUBE, VK_IMAGE_VIEW_TYPE_1D_ARRAY, VK_IMAGE_VIEW_TYPE_2D_ARRAY or VK_IMAGE_VIEW_TYPE_CUBE_ARRAY, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions with ImplicitLod, Dref or Proj in their name, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions that includes a LOD bias or any offset values, in any shader stage

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a uniform buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a storage buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If commandBuffer is an unprotected command buffer, any resource accessed by the VkPipeline object bound to the pipeline bind point used by this command must not be a protected resource

  • The current render pass must be compatible with the renderPass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • The subpass index of the current render pass must be equal to the subpass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • Every input attachment used by the current subpass must be bound to the pipeline via a descriptor set

  • Image subresources used as attachments in the current render pass must not be accessed in any way other than as an attachment by this command.

  • If the draw is recorded in a render pass instance with multiview enabled, the maximum instance index must be less than or equal to VkPhysicalDeviceMultiviewProperties::maxMultiviewInstanceIndex.

  • All vertex input bindings accessed via vertex input variables declared in the vertex shader entry point’s interface must have valid buffers bound

  • For a given vertex buffer binding, any attribute data fetched must be entirely contained within the corresponding vertex buffer binding, as described in Vertex Input Description

  • If buffer is non-sparse then it must be bound completely and contiguously to a single VkDeviceMemory object

  • buffer must have been created with the VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT bit set

  • offset must be a multiple of 4

  • commandBuffer must not be a protected command buffer

  • If countBuffer is non-sparse then it must be bound completely and contiguously to a single VkDeviceMemory object

  • countBuffer must have been created with the VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT bit set

  • countBufferOffset must be a multiple of 4

  • The count stored in countBuffer must be less than or equal to VkPhysicalDeviceLimits::maxDrawIndirectCount

  • stride must be a multiple of 4 and must be greater than or equal to sizeof(VkDrawIndirectCommand)

  • If maxDrawCount is greater than or equal to 1, (stride × (maxDrawCount - 1) + offset + sizeof(VkDrawIndirectCommand)) must be less than or equal to the size of buffer

  • If the count stored in countBuffer is equal to 1, (offset + sizeof(VkDrawIndirectCommand)) must be less than or equal to the size of buffer

  • If the count stored in countBuffer is greater than 1, (stride × (drawCount - 1) + offset + sizeof(VkDrawIndirectCommand)) must be less than or equal to the size of buffer

Valid Usage (Implicit)
  • commandBuffer must be a valid VkCommandBuffer handle

  • buffer must be a valid VkBuffer handle

  • countBuffer must be a valid VkBuffer handle

  • commandBuffer must be in the recording state

  • The VkCommandPool that commandBuffer was allocated from must support graphics operations

  • This command must only be called inside of a render pass instance

  • Each of buffer, commandBuffer, and countBuffer must have been created, allocated, or retrieved from the same VkDevice

Host Synchronization
  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Pipeline Type

Primary
Secondary

Inside

Graphics

Graphics

To record an indexed indirect draw, call:

void vkCmdDrawIndexedIndirect(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset,
    uint32_t                                    drawCount,
    uint32_t                                    stride);
  • commandBuffer is the command buffer into which the command is recorded.

  • buffer is the buffer containing draw parameters.

  • offset is the byte offset into buffer where parameters begin.

  • drawCount is the number of draws to execute, and can be zero.

  • stride is the byte stride between successive sets of draw parameters.

vkCmdDrawIndexedIndirect behaves similarly to vkCmdDrawIndexed except that the parameters are read by the device from a buffer during execution. drawCount draws are executed by the command, with parameters taken from buffer starting at offset and increasing by stride bytes for each successive draw. The parameters of each draw are encoded in an array of VkDrawIndexedIndirectCommand structures. If drawCount is less than or equal to one, stride is ignored.

Valid Usage
  • If a VkImageView is sampled with VK_FILTER_LINEAR as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT

  • If a VkImageView is accessed using atomic operations as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT

  • For each set n that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a descriptor set must have been bound to n at the same pipeline bind point, with a VkPipelineLayout that is compatible for set n, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • For each push constant that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a push constant value must have been set for the same pipeline bind point, with a VkPipelineLayout that is compatible for push constants, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • Descriptors in each bound descriptor set, specified via vkCmdBindDescriptorSets, must be valid if they are statically used by the VkPipeline bound to the pipeline bind point used by this command

  • A valid pipeline must be bound to the pipeline bind point used by this command

  • If the VkPipeline object bound to the pipeline bind point used by this command requires any dynamic state, that state must have been set for commandBuffer

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used to sample from any VkImage with a VkImageView of the type VK_IMAGE_VIEW_TYPE_3D, VK_IMAGE_VIEW_TYPE_CUBE, VK_IMAGE_VIEW_TYPE_1D_ARRAY, VK_IMAGE_VIEW_TYPE_2D_ARRAY or VK_IMAGE_VIEW_TYPE_CUBE_ARRAY, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions with ImplicitLod, Dref or Proj in their name, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions that includes a LOD bias or any offset values, in any shader stage

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a uniform buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a storage buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If commandBuffer is an unprotected command buffer, any resource accessed by the VkPipeline object bound to the pipeline bind point used by this command must not be a protected resource

  • The current render pass must be compatible with the renderPass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • The subpass index of the current render pass must be equal to the subpass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • Every input attachment used by the current subpass must be bound to the pipeline via a descriptor set

  • Image subresources used as attachments in the current render pass must not be accessed in any way other than as an attachment by this command.

  • If the draw is recorded in a render pass instance with multiview enabled, the maximum instance index must be less than or equal to VkPhysicalDeviceMultiviewProperties::maxMultiviewInstanceIndex.

  • All vertex input bindings accessed via vertex input variables declared in the vertex shader entry point’s interface must have valid buffers bound

  • For a given vertex buffer binding, any attribute data fetched must be entirely contained within the corresponding vertex buffer binding, as described in Vertex Input Description

  • If buffer is non-sparse then it must be bound completely and contiguously to a single VkDeviceMemory object

  • buffer must have been created with the VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT bit set

  • offset must be a multiple of 4

  • commandBuffer must not be a protected command buffer

  • If the multi-draw indirect feature is not enabled, drawCount must be 0 or 1

  • drawCount must be less than or equal to VkPhysicalDeviceLimits::maxDrawIndirectCount

  • If drawCount is greater than 1, stride must be a multiple of 4 and must be greater than or equal to sizeof(VkDrawIndexedIndirectCommand)

  • If the drawIndirectFirstInstance feature is not enabled, all the firstInstance members of the VkDrawIndexedIndirectCommand structures accessed by this command must be 0

  • If drawCount is equal to 1, (offset + sizeof(VkDrawIndexedIndirectCommand)) must be less than or equal to the size of buffer

  • If drawCount is greater than 1, (stride × (drawCount - 1) + offset + sizeof(VkDrawIndexedIndirectCommand)) must be less than or equal to the size of buffer

Valid Usage (Implicit)
  • commandBuffer must be a valid VkCommandBuffer handle

  • buffer must be a valid VkBuffer handle

  • commandBuffer must be in the recording state

  • The VkCommandPool that commandBuffer was allocated from must support graphics operations

  • This command must only be called inside of a render pass instance

  • Both of buffer, and commandBuffer must have been created, allocated, or retrieved from the same VkDevice

Host Synchronization
  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Pipeline Type

Primary
Secondary

Inside

Graphics

Graphics

The VkDrawIndexedIndirectCommand structure is defined as:

typedef struct VkDrawIndexedIndirectCommand {
    uint32_t    indexCount;
    uint32_t    instanceCount;
    uint32_t    firstIndex;
    int32_t     vertexOffset;
    uint32_t    firstInstance;
} VkDrawIndexedIndirectCommand;
  • indexCount is the number of vertices to draw.

  • instanceCount is the number of instances to draw.

  • firstIndex is the base index within the index buffer.

  • vertexOffset is the value added to the vertex index before indexing into the vertex buffer.

  • firstInstance is the instance ID of the first instance to draw.

The members of VkDrawIndexedIndirectCommand have the same meaning as the similarly named parameters of vkCmdDrawIndexed.

Valid Usage
  • For a given vertex buffer binding, any attribute data fetched must be entirely contained within the corresponding vertex buffer binding, as described in Vertex Input Description

  • (indexSize * (firstIndex + indexCount) + offset) must be less than or equal to the size of the bound index buffer, with indexSize being based on the type specified by indexType, where the index buffer, indexType, and offset are specified via vkCmdBindIndexBuffer

  • If the drawIndirectFirstInstance feature is not enabled, firstInstance must be 0

To record an indexed draw call with a draw call count sourced from a buffer, call:

void vkCmdDrawIndexedIndirectCountKHR(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset,
    VkBuffer                                    countBuffer,
    VkDeviceSize                                countBufferOffset,
    uint32_t                                    maxDrawCount,
    uint32_t                                    stride);
  • commandBuffer is the command buffer into which the command is recorded.

  • buffer is the buffer containing draw parameters.

  • offset is the byte offset into buffer where parameters begin.

  • countBuffer is the buffer containing the draw count.

  • countBufferOffset is the byte offset into countBuffer where the draw count begins.

  • maxDrawCount specifies the maximum number of draws that will be executed. The actual number of executed draw calls is the minimum of the count specified in countBuffer and maxDrawCount.

  • stride is the byte stride between successive sets of draw parameters.

vkCmdDrawIndexedIndirectCountKHR behaves similarly to vkCmdDrawIndexedIndirect except that the draw count is read by the device from a buffer during execution. The command will read an unsigned 32-bit integer from countBuffer located at countBufferOffset and use this as the draw count.

Valid Usage
  • If a VkImageView is sampled with VK_FILTER_LINEAR as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT

  • If a VkImageView is accessed using atomic operations as a result of this command, then the image view’s format features must contain VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT

  • For each set n that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a descriptor set must have been bound to n at the same pipeline bind point, with a VkPipelineLayout that is compatible for set n, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • For each push constant that is statically used by the VkPipeline bound to the pipeline bind point used by this command, a push constant value must have been set for the same pipeline bind point, with a VkPipelineLayout that is compatible for push constants, with the VkPipelineLayout used to create the current VkPipeline, as described in Pipeline Layout Compatibility

  • Descriptors in each bound descriptor set, specified via vkCmdBindDescriptorSets, must be valid if they are statically used by the VkPipeline bound to the pipeline bind point used by this command

  • A valid pipeline must be bound to the pipeline bind point used by this command

  • If the VkPipeline object bound to the pipeline bind point used by this command requires any dynamic state, that state must have been set for commandBuffer

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used to sample from any VkImage with a VkImageView of the type VK_IMAGE_VIEW_TYPE_3D, VK_IMAGE_VIEW_TYPE_CUBE, VK_IMAGE_VIEW_TYPE_1D_ARRAY, VK_IMAGE_VIEW_TYPE_2D_ARRAY or VK_IMAGE_VIEW_TYPE_CUBE_ARRAY, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions with ImplicitLod, Dref or Proj in their name, in any shader stage

  • If the VkPipeline object bound to the pipeline bind point used by this command accesses a VkSampler object that uses unnormalized coordinates, that sampler must not be used with any of the SPIR-V OpImageSample* or OpImageSparseSample* instructions that includes a LOD bias or any offset values, in any shader stage

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a uniform buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If the robust buffer access feature is not enabled, and if the VkPipeline object bound to the pipeline bind point used by this command accesses a storage buffer, it must not access values outside of the range of the buffer as specified in the descriptor set bound to the same pipeline bind point

  • If commandBuffer is an unprotected command buffer, any resource accessed by the VkPipeline object bound to the pipeline bind point used by this command must not be a protected resource

  • The current render pass must be compatible with the renderPass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • The subpass index of the current render pass must be equal to the subpass member of the VkGraphicsPipelineCreateInfo structure specified when creating the VkPipeline bound to VK_PIPELINE_BIND_POINT_GRAPHICS.

  • Every input attachment used by the current subpass must be bound to the pipeline via a descriptor set

  • Image subresources used as attachments in the current render pass must not be accessed in any way other than as an attachment by this command.

  • If the draw is recorded in a render pass instance with multiview enabled, the maximum instance index must be less than or equal to VkPhysicalDeviceMultiviewProperties::maxMultiviewInstanceIndex.

  • All vertex input bindings accessed via vertex input variables declared in the vertex shader entry point’s interface must have valid buffers bound

  • For a given vertex buffer binding, any attribute data fetched must be entirely contained within the corresponding vertex buffer binding, as described in Vertex Input Description

  • If buffer is non-sparse then it must be bound completely and contiguously to a single VkDeviceMemory object

  • buffer must have been created with the VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT bit set

  • offset must be a multiple of 4

  • commandBuffer must not be a protected command buffer

  • If countBuffer is non-sparse then it must be bound completely and contiguously to a single VkDeviceMemory object

  • countBuffer must have been created with the VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT bit set

  • countBufferOffset must be a multiple of 4

  • The count stored in countBuffer must be less than or equal to VkPhysicalDeviceLimits::maxDrawIndirectCount

  • stride must be a multiple of 4 and must be greater than or equal to sizeof(VkDrawIndexedIndirectCommand)

  • If maxDrawCount is greater than or equal to 1, (stride × (maxDrawCount - 1) + offset + sizeof(VkDrawIndexedIndirectCommand)) must be less than or equal to the size of buffer

  • If count stored in countBuffer is equal to 1, (offset + sizeof(VkDrawIndexedIndirectCommand)) must be less than or equal to the size of buffer

  • If count stored in countBuffer is greater than 1, (stride × (drawCount - 1) + offset + sizeof(VkDrawIndexedIndirectCommand)) must be less than or equal to the size of buffer

Valid Usage (Implicit)
  • commandBuffer must be a valid VkCommandBuffer handle

  • buffer must be a valid VkBuffer handle

  • countBuffer must be a valid VkBuffer handle

  • commandBuffer must be in the recording state

  • The VkCommandPool that commandBuffer was allocated from must support graphics operations

  • This command must only be called inside of a render pass instance

  • Each of buffer, commandBuffer, and countBuffer must have been created, allocated, or retrieved from the same VkDevice

Host Synchronization
  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Pipeline Type

Primary
Secondary

Inside

Graphics

Graphics