extensions/SGIX/GLX_SGIX_video_source.txt

XXX - Not complete yet!!!

Name

    SGIX_video_source

Name Strings

    GLX_SGIX_video_source

Version

    $Date: 1995/02/18 22:25:03 $ $Revision: 1.2 $

Number

    43

Dependencies

    SGI_make_current_read is required.

Overview

    This extension provides the capability to source pixel data from a
    video stream.  A new type of GLXDrawable (GLXVideoSourceSGIX) is
    introduced which represents the drain node of a Video Library (VL)
    path.  A GLXVideoSourceSGIX may be specified as the <read> parameter
    to glXMakeCurrentReadSGI to indicate that pixel data should be read
    from the specified video source instead of from the framebuffer.  A
    GLXVideoSourceSGIX may only be specified as a <read> drawable.

Issues

    * Should there be a way to query the configuration
      of a GLXVideoSourceSGIX?

New Procedures and Functions

    typedef XID GLXVideoSourceSGIX;

    GLXVideoSourceSGIX glXCreateGLXVideoSourceSGIX(Display *display,
						   int screen,
						   VLServer server,
						   VLPath path,
						   int nodeClass,
						   VLNode drainNode);

    void glXDestroyGLXVideoSourceSGIX(Display *dpy,
				      GLXVideoSourceSGIX glxvideosource);

New Tokens

Additions to Chapter 2 of the 1.0 Specification (OpenGL Operation)

    None.

Additions to Chapter 3 of the 1.0 Specification (Rasterization)

    None.

Additions to Chapter 4 of the 1.0 Specification (Per-Fragment Operations
and the Frame Buffer)

    None.

Additions to Chapter 5 of the 1.0 Specification (Special Functions)

    None.

Additions to Chapter 6 of the 1.0 Specification (State and State Requests)

    None.

Additions to the GLX Specification

    XXX - not complete yet

    A GLXVideoSourceSGIX is created using the glXCreateGLXVideoSourceSGIX
    command.  The parameter <display> specifies a connection to an X server.
    The parameter <screen> specifies the screen on which the GLXVideoSourceSGIX
    should be created.  The parameter <server> specifies a connection to a
    video server.  The parameter <path> specifies a video transfer path.
    The parameter <drainNode> specifies a VLNode which must be a VL_DRAIN
    node on the video transfer path specified by <path>.  The parameter
    <nodeClass> specifies the class of the VLNode specified by <drainNode>.

    A GLXVideoSourceSGIX may only be used with GLXContexts created on the
    same same screen.

    The configuration of a GLXVideoSourceSGIX is static, and is fixed at
    the time that the GLXVideoSourceSGIX is created.  If any of the controls
    which affect the transfer of video data to the GL are changed on the video
    transfer path for which a particular GLXVideoSourceSGIX was created, the
    GLXVideoSourceSGIX should be destroyed and a new GLXVideoSourceSGIX
    should be created.  Otherwise, the data read from the GLXVideoSourceSGIX
    will be undefined.

    A GLXVideoSourceSGIX is destroyed by calling glXDestroyGLXVideoSourceSGIX

Dependencies on SGI_make_current_read

    XXX - not complete yet

Errors

    XXX - not complete yet

    BadMatch is generated if glXMakeCurrent parameter <drawable> is a
    GLXVideoSourceSGIX.

    BadMatch is generated if glXMakeCurrentReadSGI parameter <draw> is a
    GLXVideoSourceSGIX.

    BadMatch is generated if glXMakeCurrentReadSGI parameter <read> is a
    GLXVideoSourceSGIX which was created for a different screen than the
    GLXContext specified by the parameter <ctx>.

    GLXBadDrawable is generated if glXDestroyGLXVideoSourceSGIX parameter
    <glxvideosource> is not a valid GLXVideoSourceSGIX.

    BadAlloc is generated if glXCreateGLXVideoSourceSGIX is unable to allocate
    the resources needed to create a GLXVideoSourceSGIX.

New State

    None.

New Implementation Dependent State

    None.