glDepthRange(3) glDepthRange(3)
NAME
glDepthRange - specify mapping of depth values from normalized device
coordinates to window coordinates
C SPECIFICATION
void glDepthRange( GLclampd zNear,
GLclampd zFar )
PARAMETERS
zNear Specifies the mapping of the near clipping plane to window coor-
dinates. The initial value is 0.
zFar Specifies the mapping of the far clipping plane to window coor-
dinates. 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 speci-
fies 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(3), glPolygonOffset(3), glViewport(3)
glDepthRange(3)
Mac OS X 10.6 - Generated Thu Sep 17 20:20:18 CDT 2009