Name

    CHROMIUM_copy_texture

Name Strings

    GL_CHROMIUM_copy_texture

Version

    Last Modifed Date: July 16, 2014

Dependencies

    OpenGL ES 2.0 is required.

    CHROMIUM_flipy affects the definition of this extension.
    EXT_texture_format_BGRA8888 affects the definition of this extension.

Overview

    This extension expands on the functionality provided by the
    glCopyTexImage2D command.  A new function is exported,
    glCopyTextureCHROMIUM, that performs the same copy operation as
    glCopyTexImage2D, while respecting the pixel-storage modifiers
    UNPACK_FLIP_Y_CHROMIUM, GL_UNPACK_PREMULTIPLY_ALPHA_CHROMIUM and
    GL_UNPACK_UNPREMULTIPLY_ALPHA_CHROMIUM.

    If GL_UNPACK_PREMULTIPLY_ALPHA_CHROMIUM and
    GL_UNPACK_UNPREMULTIPLY_ALPHA_CHROMIUM are enabled.  Then no alpha
    processing occurs.  This is the equivalent of having neither flag set.

    The extension also supports copying BGRA textures and copying
    EXTERNAL_OES texture to BGRA texture, which is not explicitly
    granted by EXT_texture_format_BGRA8888.

New Procedures and Functions

    The command

        void glCopyTextureCHROMIUM (GLenum target, GLenum source_id,
                                    GLenum dest_id,
                                    GLint internal_format, GLenum dest_type)

    Copies the contents of texture referred to by <source_id> to <dest_id>
    texture. If <source_id> texture is not defined or has different dimension
    to <dest_id> texture, define <source_id> texture same to <dest_id> texture.

    Texture level 0 is copied from the source image to level 0 of the
    destination texture.

    The internal format of the destination texture is converted to that
    specified by <internal_format>. Must be one of the following symbolic
    constants: GL_RGB, GL_RGBA
    The internal format of <source_id> texture must be one of the following
    symbolic constants: GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB,
    GL_RGBA, GL_BGRA_EXT
    When <source_id> texture doens't contain a superset of the component
    required by <internal_format>, fill the components by following rules.

                   source format          color components
             =================================================
                   GL_ALPHA               (0, 0, 0, A)
                   GL_LUMINANCE           (L, L, L, 1)
                   GL_LUMINANCE_ALPHA     (L, L, L, A)
                   GL_RGB                 (R, G, B, 1)
                   GL_RGBA                (R, G, B, A)
                   GL_BGRA_EXT            (R, G, B, A)

    The format type of the destination texture is converted to that specified
    by <dest_type>.

    <target> uses the same parameters as TexImage2D.

    INVALID_OPERATION is generated if <internal_format> is not one of the valid formats
    described above.

    INVALID_OPERATION is generated if the internal format of <source_id> is not one of
    formats from the table above.

    INVALID_VALUE is generated if <target> is not GL_TEXTURE_2D.

    INVALID_VALUE is generated if <source_id> or <dest_id> are not valid texture
    objects.

    INVALID_VALUE is generated if textures corresponding to <dest_id> have not
    been bound as GL_TEXTURE_2D object.

    INVALID_VALUE is generated if textures corresponding to <source_id> have not
    been bound as GL_TEXTURE_2D, GL_TEXTURE_RECTANGLE_ARB or
    GL_TEXTURE_EXTERNAL_OES objects.

    INVALID_VALUE is generated if level 0 of the source texture is not defined.

    The command

        void glCopySubTextureCHROMIUM (GLenum target, GLenum source_id,
                                       GLenum dest_id,
                                       GLint xoffset, GLint yoffset)

    Copies the sub contents of texture referred to by <source_id> to <dest_id>
    texture without redefining <dest_id> texture.

    See CopyTextureCHROMIUM for the interpretation of the <target> arguments.

    <xoffset> and <yoffset> specify a texel offset in the x and y direction
    respectively within the destination texture.

    INVALID_OPERATION is generated if source internal_format and destination
    internal_format are not one of the valid formats described above.

    INVALID_VALUE is generated if <target> is not GL_TEXTURE_2D.

    INVALID_OPERATION is generated if the destination texture has not been
    defined.

    INVALID_VALUE is generated if level 0 of the source texture or
    the destination texture is not defined.

    INVALID_VALUE is generated if <xoffset> < 0 , or <yoffset> < 0.

    INVALID_VALUE is generated if (<xoffset> + source_width) > dest_width,
    or (<yoffset> + source_height) > dest_height.

Errors

    None.

New Tokens

    None.

New State

    None.

Revision History

    8/1/2011    Documented the extension
    7/4/2013    Add a new parameter dest_type to glCopyTextureCHROMIUM()
    16/7/2014   Add GL_TEXTURE_RECTANGLE_ARB as valid source_id target.