NAME    [Toc]    [Back]

       glDepthRange  -  specify mapping of depth values from normalized
 device coordinates to window coordinates

SYNOPSIS    [Toc]    [Back]

       void glDepthRange(
               GLclampd zNear,
               GLclampd zFar );

PARAMETERS    [Toc]    [Back]

       Specifies the mapping of the near clipping plane to window
       coordinates.  The  initial value is 0.  Specifies the mapping
 of the far clipping plane to window coordinates.  The
       initial value is 1.

DESCRIPTION    [Toc]    [Back]

       After  clipping and division by w, depth coordinates range
       from -1 to 1, corresponding to the near and  far  clipping
       planes.   glDepthRange() specifies a linear mapping of the
       normalized depth coordinates in this range to window depth
       coordinates.  Regardless of the actual depth buffer implementation,
 window coordinate depth values are  treated  as
       though  they  range  from  0  through 1 (like color components).
 Thus, the values accepted  by  glDepthRange()  are
       both clamped to this range before they are accepted.

       The  setting of (0,1) maps the near plane to 0 and the far
       plane to 1.  With this mapping, the depth buffer range  is
       fully utilized.

NOTES    [Toc]    [Back]

       It  is not necessary that zNear be less than zFar. Reverse
       mappings such as "zNear" = 1, and "zFar" = 0  are  acceptable.

ERRORS    [Toc]    [Back]

       GL_INVALID_OPERATION  is  generated  if  glDepthRange() is
       executed between the execution of glBegin() and the corresponding
 execution of glEnd().

ASSOCIATED GETS    [Toc]    [Back]

       glGet() with argument GL_DEPTH_RANGE

SEE ALSO    [Toc]    [Back]

       glDepthFunc(3), glPolygonOffset(3), glViewport(3)



                                                 glDepthRange(3G)