extensions/ANGLE_read_only_depth_stencil_feedback_loops.txt

Name

    ANGLE_read_only_depth_stencil_feedback_loops

Name Strings

    GL_ANGLE_read_only_depth_stencil_feedback_loops

Contributors

    Jamie Madill, Google Inc.
    Shahbaz Youssefi, Google Inc.

Contact

    Jamie Madill, Google Inc. (jmadill 'at' google 'dot' com)

Status

    WIP

Version

    Last Modified Date: Dec 22, 2022
    Author Revision: 1

Number

    OpenGL ES Extension ###

Dependencies

    OpenGL ES 3.0 is required.

    The extension is written against the OpenGL ES 3.2 specification.

Overview

    This extension allows defined results when reading from a depth or stencil
    texture that is bound as a read-only depth or stencil buffer.

IP Status

    No known IP claims.

New Procedures and Functions

    None

New Tokens

    None

Additions to Chapter 8 of the OpenGL ES 3.2 Specification (Textures and
Samplers)

    Added to the list of conditions in 8.14.2.1 (Rendering Feedback Loops):

    "The texture is not a depth texture, or the value of
    DEPTH_WRITEMASK is not FALSE."

    "The texture is not a stencil texture, or stencil is not being modified."

Additions to Chapter 9 of the OpenGL ES 3.1 Specification (Framebuffers and
Framebuffer Objects)

    Removed from the end of section in 9.3.1 (Rendering Feedback Loops):

    "Also note that even if writing to a given texture is disabled (e.g. via the color,
    depth, or stencil writemasks) during rendering, a feedback loop will still occur."

    Added from the end of section in 9.3.1 (Rendering Feedback Loops):

    "Note that if writing to a given depth texture is disabled (via the depth
    writemask) during rendering, a feedback loop will not occur.  Additionally,
    if writing to a given stencil texture is disabled (via the stencil mask and ops),
    a feedback loop will not occur."

Errors

    None

New State

    None

Issues

    TBD

Revision History

    Revision 2, 2022/12/22
      - Adjust language to exclude read-only stencil from feedback loop
    Revision 1, 2022/05/09
      - Initial revision.