xref: /third_party/openGLES/extensions/I3D/WGL_I3D_digital_video_control.txt

Name

    WGL_I3D_digital_video_control

Name Strings

    WGL_I3D_digital_video_control

Contact

    Dale Kirkland, Intense3D (dlkirkla 'at' intense3d.com)

Status

    Complete

Version

    Date: 04/17/2000   Revision 1.0

Number

    250

Dependencies

    The extension is written against the OpenGL 1.2.1 Specification
    although it should work on any previous OpenGL specification.

    The WGL_EXT_extensions_string extension is required.

    WGL_I3D_gamma affects the definition of this extension.

Overview

    The digital video control extension controls digital video data,
    such as whether it is gamma corrected or the cursor is injected
    into the video stream.

IP Status

    None

Issues

    None

New Procedures and Functions

    BOOL wglGetDigitalVideoParametersI3D(HDC hDC,
                                         int iAttribute,
                                         int *piValue)

    BOOL wglSetDigitalVideoParametersI3D(HDC hDC,
                                         int iAttribute,
                                         const int *piValue)

New Tokens

    Accepted by the <iAttribute> parameter of wglGetDigitalVideoParametersI3D
    and wglSetDigitalVideoParametersI3D:

      WGL_DIGITAL_VIDEO_CURSOR_ALPHA_FRAMEBUFFER_I3D    0x2050
      WGL_DIGITAL_VIDEO_CURSOR_ALPHA_VALUE_I3D          0x2051
      WGL_DIGITAL_VIDEO_CURSOR_INCLUDED_I3D             0x2052
      WGL_DIGITAL_VIDEO_GAMMA_CORRECTED_I3D             0x2053

Additions to Chapter 2 of the OpenGL 1.2.1 Specification (OpenGL Operation)

    None

Additions to Chapter 3 of the OpenGL 1.2.1 Specification (Rasterization)

    None

Additions to Chapter 4 of the OpenGL 1.2.1 Specification (Per-Fragment
Operations and the Frame Buffer)

    None

Additions to Chapter 5 of the OpenGL 1.2.1 Specification (Special Functions)

    None

Additions to Chapter 6 of the OpenGL 1.2.1 Specification (State and
State Requests)

    None

Additions to Appendix A of the OpenGL 1.2.1 Specification (Invariance)

    None

Additions to the WGL Specification

    Digital video data is controlled by parameters that are set with
    the function wglSetDigitalVideoParametersI3D:

      BOOL wglSetDigitalVideoParametersI3D(HDC hDC,
                                           int iAttribute,
                                           const int *piValue)

    <hDC> is a device context for a graphics adapter or a window
    residing on a device that supports digital video.  For multiple
    monitor systems, only the digital video mode associated with <hDC>
    is set.

    <iAttribute> must be one of the following values:

      WGL_DIGITAL_VIDEO_CURSOR_ALPHA_FRAMEBUFFER_I3D
          Specifies the source of the cursor data's alpha component.
          If the value pointed to by <piValue> is non-zero, the
          alpha component of the cursor data comes from the
          framebuffer. If the value pointed to by <piValue> is
          zero the alpha component of the cursor is specified by
          WGL_DIGITAL_VIDEO_CURSOR_ALPHA_VALUE_I3D. The default
          value is zero.

      WGL_DIGITAL_VIDEO_CURSOR_ALPHA_VALUE_I3D
          Determines the alpha component of the cursor.  The value
          pointed to by <piValue> is converted by the following
          equation:

                          ((2 * <*piValue>) + 1)
                          ----------------------
                              (2^32 - 1)

          and the result is clamped to [0, 1].  The clamped result is
          multiplied by 2^n - 1, where 'n' is the number of bits in the
          alpha buffer.  The digital video data will have the result as
          the cursor data's alpha component.  The default alpha value
          is 2^31 - 1.

      WGL_DIGITAL_VIDEO_CURSOR_INCLUDED_I3D
          Specifies whether cursor data is included in the digital
          video data.  If the value pointed to by <piValue> is
          non-zero, the digital video data contains cursor data.
          Otherwise the digital video data does not contain cursor
          data.  This value defaults to zero.

      WGL_DIGITAL_VIDEO_GAMMA_CORRECTED_I3D
          Specifies whether the digital video data is gamma
          corrected.  If the value pointed to by <piValue> is non-zero,
          the digital video data is gamma corrected.  Otherwise, the
          digital video data is not gamma corrected.  This value
          defaults to zero.

    Digital video parameters can be queried with the function
    wglGetDigitalVideoParametersI3D:

      BOOL wglGetDigitalVideoParametersI3D(HDC hDC,
                                           int iAttribute,
                                           int *piValue)

    <hDC> is a device context for a graphics adapter or a window
    residing on a device that supports digital video.  For multiple
    monitor systems, only the digital video mode parameters associated
    with <hDC> are returned.

    <iAttribute> must be one of the following values:

      WGL_DIGITAL_VIDEO_CURSOR_ALPHA_FRAMEBUFFER_I3D
          <piValue> returns one value indicating the source of the cursor
          data's alpha component.  If the value is non-zero then the
          alpha component of the cursor data comes from the framebuffer.
          Otherwise, the value of the cursor's alpha data is determined
          by the value specified by
          WGL_DIGITAL_VIDEO_CURSOR_ALPHA_VALUE_I3D.

      WGL_DIGITAL_VIDEO_CURSOR_ALPHA_VALUE_I3D
          <piValue> returns the user-specified alpha component of
          the cursor's data.

      WGL_DIGITAL_VIDEO_CURSOR_INCLUDED_I3D
          <piValue> returns one value indicating whether cursor data is
          present in the digital video data.  If the value is non-zero
          then cursor data is present in the digital video data.

      WGL_DIGITAL_VIDEO_GAMMA_CORRECTED_I3D
          <piValue> returns one value indicating whether the digital
          video data is gamma corrected.  If the value is non-zero then
          the digital video data is gamma corrected.

Dependencies on WGL_EXT_extensions_string

    Because there is no way to extend wgl, these calls are defined in
    the ICD and can be called by obtaining the address with
    wglGetProcAddress.  Because this extension is a WGL extension, it
    is not included in the GL_EXTENSIONS string.  Its existence can be
    determined with the WGL_EXT_extensions_string extension.

Dependencies on WGL_I3D_gamma

    If WGL_I3D_gamma is supported, the <iAttribute> parameter of
    WGLGetDigitalVideoParametersI3D and WGLSetDigitalVideoParametersI3D
    accepts WGL_DIGITAL_VIDEO_GAMMA_CORRECTED_I3D.  Otherwise it does
    not.

Errors

    If the function succeeds, a value of TRUE is returned.  If the
    function fails, a value of FALSE is returned.  To get extended
    error information, call GetLastError.

      ERROR_DC_NOT_FOUND         The <hDC> was not valid.

      ERROR_NO_SYSTEM_RESOURCES  There is no support for digital video
                                 for the device specified by <hDC>.

      ERROR_INVALID_DATA         <iAttribute> is not a valid value.

New State

    None

New Implementation Dependent State

    None

Revision History

    12/03/1999  0.1  First draft.
    01/05/2000  0.2  Enumerants assigned
    04/17/2000  1.0  Driver released to ISVs.