Name

    CHROMIUM_texture_mailbox

Name Strings

    GL_CHROMIUM_texture_mailbox

Version

    Last Modifed Date: April 25, 2012

Dependencies

    OpenGL ES 2.0 is required.

Overview

    This extension defines a way of sharing texture image data between texture
    objects in different contexts where the contexts would not normally share
    texture resources. Three new functions are exported. glGenMailboxCHROMIUM
    generates a name that can be used to identify texture image data outside
    the scope of a context group. glProduceMailboxCHROMIUM moves texture image
    data out of a texture object and into a mailbox. glConsumeMailboxCHROMIUM
    moves texture image data out of a mailbox and into a texture object.

New Procedures and Functions

    void glGenMailboxCHROMIUM (GLbyte *mailbox)

    Generates a unique name identifying a mailbox. The name is generated using
    a cryptographic random number generator and is intended to be difficult to
    guess. The scope of the name is implementation specific, for example it
    might not span multiple displays.

    <mailbox> returns a GL_MAILBOX_SIZE_CHROMIUM byte sized name


    void glProduceTextureCHROMIUM (GLenum target, const GLbyte *mailbox)

    Moves the image data of the currently bound texture object into the mailbox.
    The texture object is redefined as though all its levels had been resized to
    zero by zero and the texture object is therefore incomplete. If the mailbox
    previously contained image data, the old image data is deleted. The state
    of the bound texture object is not saved in the mailbox, only the image
    data, as well as the immutable state. The texture object is no longer
    immutable.

    If glProduceTextureCHROMIUM generates an error, the associated image data
    is preserved in the texture object.

    The mailbox is emptied and the texture image data deleted if the context
    is destroyed before being consumed. See glConsumeTextureCHROMIUM.

    <target> uses the same parameters as TexImage2D.

    <mailbox> identifies a GL_MAILBOX_SIZE_CHROMIUM byte sized name returned by
    glGenMailboxCHROMIUM.

    INVALID_OPERATION is generated if <target> is not a valid target.

    INVALID_OPERATION is generated if the texture is attached to a framebuffer.

    INVALID_OPERATION is generated if the texture is immutable.

    INVALID_OPERATION is generated if <mailbox> is invalid.


    void glConsumeTextureCHROMIUM (GLenum target, const GLbyte *mailbox)

    <target> uses the same parameters as TexImage2D.

    <mailbox> identifies a GL_MAILBOX_SIZE_CHROMIUM byte sized name returned by
    glGenMailboxCHROMIUM.

    Redefines the image data of the currently bound texture object with the
    image data in the mailbox and empties the mailbox. The state of the
    currently bound texture object is not modified, only the image data. All
    levels are redefined, and the immutable state is set according to the
    contents of the mailbox.

    If glConsumeTextureCHROMIUM generates an error, the associated image data
    is preserved in the texture object.

    INVALID_OPERATION is generated if <target> is not a valid target.

    INVALID_OPERATION is generated if <mailbox> is empty.

    INVALID_OPERATION is generated if <mailbox> is not in the scope of the
    context.

    INVALID_OPERATION is generated if <mailbox> is invalid.

    INVALID_OPERATION is generated if the texture is attached to a framebuffer.

    INVALID_OPERATION is generated if the texture is immutable.

    INVALID_OPERATION is generated if the image data is invalid in the current
    context.

New Tokens

    The size of a mailbox name in bytes.

        GL_MAILBOX_SIZE_CHROMIUM                             64

Errors

    None.

New Tokens

    None.

New State

    None.

Revision History

    4/25/2011    Documented the extension