GLES2/extensions/CHROMIUM/CHROMIUM_command_buffer_query.txt

Name

    CHROMIUM_command_buffer_query

Name Strings

    GL_CHROMIUM_command_buffer_query

Version

    Last Modified Date: August 19, 2019

Dependencies

    None.

Overview

    This extension provides a query mechanism that allows the client to get
    timing information from the Chromium command buffer.

    GL_COMMANDS_ISSUED_CHROMIUM can be used to measure the time elapsed in
    microseconds between a BeginQueryEXT and an EndQueryEXT. This is the time
    that it takes to issue the enclosed commands to the underlying driver (not
    the time it takes to complete them). It only counts time during which the
    associated context is scheduled. The value of the timer can be obtained
    using GetQueryObjectuivEXT.

    GL_COMMANDS_ISSUED_TIMESTAMP_CHROMIUM can be used as the target to
    QueryCounterEXT to obtain the timestamp in microseconds at which the
    QueryCounterEXT is reached on the service-side command buffer. This is
    useful to know by what time all the commands prior to the QueryCounterEXT
    have been issued to the underlying driver (but have not necessarily
    completed). The timestamp value can be obtained using
    GetQueryObjectui64vEXT.

New Procedures and Functions

    void BeginQueryEXT(enum target, uint id);
    void EndQueryEXT(enum target);
    void QueryCounterEXT(uint id, enum target);
    void GetQueryivEXT(enum target, enum pname, int *params);
    void GetQueryObjectuivEXT(uint id, enum pname, uint *params);
    void GetQueryObjectui64vEXT(uint id, enum pname, uint64 *params);

Errors

    None.

New Tokens

    Accepted by the <target> parameter of BeginQueryEXT, EndQueryEXT,
    and GetQueryivEXT:

        GL_COMMANDS_ISSUED_CHROMIUM                     0x6004

    Accepted by the <target> parameter of QueryCounterEXT and GetQueryivEXT:

        GL_COMMANDS_ISSUED_TIMESTAMP_CHROMIUM           0x6005

New State

    None.

Revision History

    8/19/2019   Documented the extension