2010
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 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/.