C Specification

To record an indirect command dispatch, call:

void vkCmdDispatchIndirect(
    VkCommandBuffer                             commandBuffer,
    VkBuffer                                    buffer,
    VkDeviceSize                                offset);

Parameters

  • commandBuffer is the command buffer into which the command will be recorded.

  • buffer is the buffer containing dispatch parameters.

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

Description

vkCmdDispatchIndirect behaves similarly to vkCmdDispatch except that the parameters are read by the device from a buffer during execution. The parameters of the dispatch are encoded in a VkDispatchIndirectCommand structure taken from buffer starting at offset.

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

  • For each set n that is statically used by the VkPipeline currently bound to VK_PIPELINE_BIND_POINT_COMPUTE, a descriptor set must have been bound to n at VK_PIPELINE_BIND_POINT_COMPUTE, with a VkPipelineLayout that is compatible for set n, with the VkPipelineLayout used to create the current VkPipeline, as described in ../../html/vkspec.html#descriptorsets-compatibility

  • Descriptors in each bound descriptor set, specified via vkCmdBindDescriptorSets, must be valid if they are statically used by the currently bound VkPipeline object, specified via vkCmdBindPipeline

  • A valid compute pipeline must be bound to the current command buffer with VK_PIPELINE_BIND_POINT_COMPUTE

  • buffer must have been created with the VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT bit set

  • offset must be a multiple of 4

  • The sum of offset and the size of VkDispatchIndirectCommand must be less than or equal to the size of buffer

  • For each push constant that is statically used by the VkPipeline currently bound to VK_PIPELINE_BIND_POINT_COMPUTE, a push constant value must have been set for VK_PIPELINE_BIND_POINT_COMPUTE, with a VkPipelineLayout that is compatible for push constants with the one used to create the current VkPipeline, as described in ../../html/vkspec.html#descriptorsets-compatibility

  • If any VkSampler object that is accessed from a shader by the VkPipeline currently bound to VK_PIPELINE_BIND_POINT_COMPUTE uses unnormalized coordinates, it 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 any VkSampler object that is accessed from a shader by the VkPipeline currently bound to VK_PIPELINE_BIND_POINT_COMPUTE uses unnormalized coordinates, it 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 any VkSampler object that is accessed from a shader by the VkPipeline currently bound to VK_PIPELINE_BIND_POINT_COMPUTE uses unnormalized coordinates, it 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 any shader stage in the VkPipeline object currently bound to VK_PIPELINE_BIND_POINT_COMPUTE accesses a uniform buffer, it must not access values outside of the range of that buffer specified in the currently bound descriptor set

  • If the robust buffer access feature is not enabled, and any shader stage in the VkPipeline object currently bound to VK_PIPELINE_BIND_POINT_COMPUTE accesses a storage buffer, it must not access values outside of the range of that buffer specified in the currently bound descriptor set

  • Any VkImageView being sampled with VK_FILTER_LINEAR as a result of this command must be of a format which supports linear filtering, as specified by the VK_FORMAT_FEATURE_SAMPLED_IMAGE_FILTER_LINEAR_BIT flag in VkFormatProperties::linearTilingFeatures (for a linear image) or VkFormatProperties::optimalTilingFeatures(for an optimally tiled image) returned by vkGetPhysicalDeviceFormatProperties

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 compute operations

  • This command must only be called outside 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

Outside

Compute

Compute

See Also

VkBuffer, VkCommandBuffer, VkDeviceSize

Document Notes

For more information, see the Vulkan Specification at URL

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

Copyright (c) 2014-2017 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.