2010-2013
Khronos Group
glDepthRangeIndexed
3G

# glDepthRangeIndexed

specify mapping of depth values from normalized device coordinates to window coordinates for a specified viewport

## C Specification

                    void glDepthRangeIndexed
                    GLuint index
                    GLdouble nearVal
                    GLdouble farVal

## Parameters

`index`

  Specifies the index of the viewport whose depth range to update.

`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. Each viewport has an independent depth range specified as 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). `glDepthRangeIndexed` specifies a linear mapping of the normalized depth coordinates in this range to window depth coordinates for a specified viewport. Thus, the values accepted by `glDepthRangeIndexed` are both clamped to this range before they are accepted.

The `index` parameter specifies the index of first viewport whose depth range to modify and must be less than the value of `GL_MAX_VIEWPORTS`. `nearVal` and `farVal` specify near and far values of the depth range for the specified viewport, respectively.

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 the near plane distance be less than the far plane distance. Reverse mappings such as nearVal = 1 , and farVal = 0 are acceptable.

The type of the `nearVal` and `farVal` parameters was changed from GLclampd to GLdouble. This change is transparent to user code and is described in detail on the removedTypes page.

## Errors

`GL_INVALID_VALUE` is generated if `index` is greater than or equal to the value of `GL_MAX_VIEWPORTS`.

## Associated Gets

glGet with argument `GL_DEPTH_RANGE`

## See Also

glDepthFunc, glDepthRange, glDepthRangeArray, glPolygonOffset, glViewportArray, glViewport, removedTypes

## Copyright

Copyright 2010-2013 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.