gpu/GLES2/extensions/CHROMIUM/CHROMIUM_stream_texture_matrix.txt

Name

    CHROMIUM_stream_texture_matrix

Name Strings

    CHROMIUM_stream_texture_matrix

Version

    Last Modifed Date: February 16, 2016

Dependencies

    OpenGL ES 2.0 is required.

Overview

    Allows clients to set the value of a 4x4 uniform to the current texture
    matrix of a stream texture.

    Allows shader access to the texture matrix for the current front buffer
    of a stream texture.  Intended for use with Android SurfaceTexture, which
    doesn't provide the value until the front buffer is latched.

    Also allows hints about whether an image could be promoted to an overlay.

New Procedures and Functions

    The command

       void UniformMatrix4fvStreamTextureMatrixCHROMIUM(
               GLintUniformLocation location,
               GLbooleanFalseOnly transpose,
               const GLfloat* transform)

    Updates a uniform to match the current stream texture's texture matrix
    multiplied by transform. The stream texture must be bound to the
    GL_TEXTURE_EXTERNAL_OES target on the active texture unit.

    If the bound texture is not a stream texture, then the identity matrix is
    used instead.

    <location> Specifies the 4x4f uniform location to be modified.
    <transpose> Specifies whether the matrix should be transposed.
    <transform> Provides an additional transform matrix that is applied
      prior to the the stream texture transformation matrix.

    The command

       void OverlayPromotionHintCHROMIUM(
               GLuint texture,
               GLboolean promotion_hint,
               GLint display_x,
               GLint display_y)

    Provides a hint about whether the GLImage bound to texture could be promoted
    to an overlay or not.

    <texture> is the texture id, which should have a stream texture image bound
      to it.
    <promotion_hint> indicates whether the GLImage could be promoted.
    <display_x> is the x coordinate of the origin of the overlay if the image
      could be promoted.  Otherwise, it is 0.
    <display_y> is the y coordinate of the origin of the overlay if the image
      could be promoted.  Otherwise, it is 0.


    If <texture> is not a valid texture, or if it doesn't have a stream texture
    image bound to it, then no action is taken.

Errors

    None.

New State

    None.

Revision History

    02/16/2016    Documented the extension
    03/21/2016    Amended the interpretation of the matrix argument.