Name

    MESA_texture_const_bandwidth

Name Strings

    GL_MESA_texture_const_bandwidth

Contact

    Rob Clark <robdclark@chromium.org>

Contributors

    Rob Clark, Google
    Lina Versace, Google
    Tapani Pälli, Intel

Status

    Proposal

Version

    Version 1, September, 2023

Number

    tbd

Dependencies

    Requires EXT_memory_object.

Overview

    The use of data dependent bandwidth compressed formats (UBWC, AFBC, etc)
    can introduce a form of side-channel, in that the bandwidth used for
    texture access is dependent on the texture's contents.  In some cases
    an application may want to disable the use of data dependent formats on
    specific textures.

    For that purpose, this extension extends EXT_memory_object to introduce
    a new <param> CONST_BW_TILING_MESA.

IP Status

    None

Issues

    None

New Procedures and Functions

    None

New Types

    None

New Tokens

    Returned in the <params> parameter of GetInternalFormativ or
    GetInternalFormati64v when the <pname> parameter is TILING_TYPES_EXT,
    returned in the <params> parameter of GetTexParameter{if}v,
    GetTexParameterI{i ui}v, GetTextureParameter{if}v, and
    GetTextureParameterI{i ui}v when the <pname> parameter is
    TEXTURE_TILING_EXT, and accepted by the <params> parameter of
    TexParameter{ifx}{v}, TexParameterI{i ui}v, TextureParameter{if}{v},
    TextureParameterI{i ui}v when the <pname> parameter is
    TEXTURE_TILING_EXT:

        CONST_BW_TILING_MESA                       0x8BBE

Errors

    None

Revision History

    Version 1, 2023-9-28 (Rob Clark)
        Initial draft.