// Copyright (c) 2014-2016 Khronos Group. This work is licensed under a
// Creative Commons Attribution 4.0 International License; see
// http://creativecommons.org/licenses/by/4.0/

vkCmdBeginQuery(3)
==================

Name
----
vkCmdBeginQuery - Begin a query.

C Specification
---------------

// refBegin vkCmdBeginQuery Begin a query.

To begin a query, call:

include::../protos/vkCmdBeginQuery.txt[]


Parameters
----------

  * pname:commandBuffer is the command buffer into which this command will
    be recorded.
  * pname:queryPool is the query pool that will manage the results of the
    query.
  * pname:query is the query index within the query pool that will contain
    the results.
  * pname:flags is a bitmask indicating constraints on the types of queries
    that can: be performed. Bits which can: be set include:
+
// refBegin VkQueryControlFlagBits - Bitmask specifying constraints on a query
include::../enums/VkQueryControlFlagBits.txt[]


Description
-----------

If the pname:queryType of the pool is ename:VK_QUERY_TYPE_OCCLUSION and
pname:flags contains ename:VK_QUERY_CONTROL_PRECISE_BIT, an implementation
must: return a result that matches the actual number of samples passed. This
is described in more detail in <<queries-occlusion,Occlusion Queries>>.

[[queries-operation-active]]
After beginning a query, that query is considered _active_ within the command
buffer it was called in until that same query is ended. Queries active in a
primary command buffer when secondary command buffers are executed are
considered active for those secondary command buffers.

include::../validity/protos/vkCmdBeginQuery.txt[]


See Also
--------

slink:VkCommandBuffer, elink:VkQueryControlFlags, slink:VkQueryPool


Document Notes
--------------

For more information, see the Vulkan Specification at URL

https://www.khronos.org/registry/vulkan/specs/1.0/xhtml/vkspec.html#vkCmdBeginQuery

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

include::footer.txt[]