- specify mapping of depth values from normalized device
coordinates to window coordinates
C SPECIFICATION
PARAMETERS
_param1 Specifies the mapping of the near clipping plane
to window coordinates. The initial value is 0.
_param2 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 imple-
mentation, window coordinate depth values are treated as
though they range from 0 through 1 (like color compo-
nents). 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 _param1 be less than _param2.
Reverse mappings such as _eqnparam1=1, and _eqnparam2=0
are acceptable.
ERRORS
GL_INVALID_OPERATION is generated if glDepthRange is exe-
cuted between the execution of glBegin and the correspond-
ing execution of glEnd.
ASSOCIATED GETS
glGet with argument GL_DEPTH_RANGE
SEE ALSO
glDepthFunc, glPolygonOffset, glViewport
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