1991-2006
Silicon Graphics, Inc.
2010-2013
Khronos Group
glDepthRange
3G
glDepthRange
specify mapping of depth values from normalized device coordinates to window coordinates
C Specification
void glDepthRange
GLdouble nearVal
GLdouble farVal
void glDepthRangef
GLfloat nearVal
GLfloat farVal
Parameters
nearVal
Specifies the mapping of the near clipping plane to window coordinates.
The initial value is 0.
farVal
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 nearVal be less than farVal.
Reverse mappings such as
nearVal
=
1
,
and
farVal
=
0
are acceptable.
The type of the nearVal and
farVal parameters was changed from
GLclampf to GLfloat for glDepthRangef
and from GLclampd to GLdouble for
glDepthRange. This change is
transparent to user code and is described in detail on the
removedTypes
page.
Associated Gets
glGet with argument GL_DEPTH_RANGE
See Also
glDepthFunc,
glPolygonOffset,
glViewport,
removedTypes
Copyright
Copyright 1991-2006 Silicon Graphics, Inc.
Copyright 2010-2013 Khronos Group.
This document is licensed under the SGI Free Software B License.
For details, see
http://oss.sgi.com/projects/FreeB/.