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/.