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GLDEPTHRANGE(3G)                                                                            GLDEPTHRANGE(3G)



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


C SPECIFICATION
       void glDepthRange( GLclampd zNear,
                          GLclampd zFar )


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

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

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

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

ASSOCIATED GETS
       glGet with argument GL_DEPTH_RANGE

SEE ALSO
       glDepthFunc(3G), glPolygonOffset(3G), glViewport(3G)




                                                                                            GLDEPTHRANGE(3G)