[ новости /+++ | форум | теги | ]

NAME
     glXGetConfig - return information about GLX visuals


C SPECIFICATION
     int glXGetConfig( Display *dpy,
                       XVisualInfo *vis,
                       int attrib,
                       int *value )


PARAMETERS
     dpy     Specifies the connection to the X server.

     vis     Specifies the visual to be queried.  It is a pointer
             to  an  XVisualInfo  structure, not a visual ID or a
             pointer to a Visual.

     attrib  Specifies the visual attribute to be returned.

     value   Returns the requested value.

DESCRIPTION
     glXGetConfig sets value to the attrib value  of  windows  or
     GLX  pixmaps  created  with  respect  to  vis.  glXGetConfig
     returns an error code if it fails for  any  reason.   Other-
     wise, zero is returned.

     attrib is one of the following:

     GLX_USE_GL            True if OpenGL rendering is  supported
                           by this visual, False otherwise.

     GLX_BUFFER_SIZE       Number of bits per color buffer.   For
                           RGBA  visuals,  GLX_BUFFER_SIZE is the
                           sum of  GLX_RED_SIZE,  GLX_GREEN_SIZE,
                           GLX_BLUE_SIZE,   and   GLX_ALPHA_SIZE.
                           For     color      index      visuals,
                           GLX_BUFFER_SIZE  is  the  size  of the
                           color indexes.

     GLX_LEVEL             Frame  buffer  level  of  the  visual.
                           Level   zero   is  the  default  frame
                           buffer.  Positive levels correspond to
                           frame buffers that overlay the default
                           buffer, and negative levels correspond
                           to  frame  buffers  that  underlay the
                           default buffer.

     GLX_RGBA              True  if  color  buffers  store   red,
                           green,  blue, and alpha values.  False
                           if they store color indexes.

     GLX_DOUBLEBUFFER      True  if  color   buffers   exist   in
                           front/back  pairs that can be swapped,
                           False otherwise.

     GLX_STEREO            True  if  color   buffers   exist   in
                           left/right pairs, False otherwise.

     GLX_AUX_BUFFERS       Number of auxiliary color buffers that
                           are available.  Zero indicates that no
                           auxiliary color buffers exist.

     GLX_RED_SIZE          Number of bits of red stored  in  each
                           color  buffer.   Undefined if GLX_RGBA
                           is False.

     GLX_GREEN_SIZE        Number of bits of green stored in each
                           color  buffer.   Undefined if GLX_RGBA
                           is False.

     GLX_BLUE_SIZE         Number of bits of blue stored in  each
                           color  buffer.   Undefined if GLX_RGBA
                           is False.

     GLX_ALPHA_SIZE        Number of bits of alpha stored in each
                           color  buffer.   Undefined if GLX_RGBA
                           is False.

     GLX_DEPTH_SIZE        Number of bits in the depth buffer.

     GLX_STENCIL_SIZE      Number of bits in the stencil buffer.

     GLX_ACCUM_RED_SIZE    Number of bits of red  stored  in  the
                           accumulation buffer.

     GLX_ACCUM_GREEN_SIZE  Number of bits of green stored in  the
                           accumulation buffer.

     GLX_ACCUM_BLUE_SIZE   Number of bits of blue stored  in  the
                           accumulation buffer.

     GLX_ACCUM_ALPHA_SIZE  Number of bits of alpha stored in  the
                           accumulation buffer.

     The X protocol allows a single visual ID to be  instantiated
     with  different  numbers  of bits per pixel.  Windows or GLX
     pixmaps that will be rendered with OpenGL, however, must  be
     instantiated with a color buffer depth of GLX_BUFFER_SIZE.

     Although a GLX implementation can export many  visuals  that
     support  GL  rendering,  it  must  support at least one RGBA
     visual. This visual must have at least one color  buffer,  a
     stencil buffer of at least 1 bit, a depth buffer of at least
     12 bits, and an accumulation buffer.   Alpha  bitplanes  are
     optional  in  this  visual.   However, its color buffer size
     must  be  as  great  as  that  of  the  deepest   TrueColor,
     DirectColor, PseudoColor, or StaticColor visual supported on
     level zero, and it must itself be made  available  on  level
     zero.

     In addition, if the X server exports a PseudoColor  or  Sta-
     ticColor visual on framebuffer level 0, a color index visual
     is also required on that level.  It must have at  least  one
     color  buffer,  a  stencil  buffer  of at least 1 bit, and a
     depth buffer of at least 12 bits.  This visual must have  as
     many  color  bitplanes  as  the  deepest PseudoColor or Sta-
     ticColor visual supported on level 0.

     Applications are best written to select the visual that most
     closely  meets  their requirements.  Creating windows or GLX
     pixmaps with  unnecessary  buffers  can  result  in  reduced
     rendering performance as well as poor resource allocation.

NOTES
     XVisualInfo is defined in Xutil.h.  It is a  structure  that
     includes visual, visualID, screen, and depth elements.

ERRORS
     GLX_NO_EXTENSION is returned if dpy does not support the GLX
     extension.

     GLX_BAD_SCREEN is returned if the screen  of  vis  does  not
     correspond to a screen.

     GLX_BAD_ATTRIBUTE is returned if attrib is not a  valid  GLX
     attribute.

     GLX_BAD_VISUAL is returned if vis doesn't support GLX and an
     attribute other than GLX_USE_GL is requested.

SEE ALSO
     glXChooseVisual, glXCreateContext

Партнёры:

Хостинг: