glDepthRange — specify mapping of depth values from normalized device coordinates to window coordinates
void glDepthRange( | GLclampd | nearVal, |
GLclampd | farVal) ; |
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.
After clipping and division by w,
depth coordinates range from
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.
It is not necessary that nearVal
be less than farVal
.
Reverse mappings such as
GL_INVALID_OPERATION
is generated if glDepthRange
is executed between the execution of glBegin
and the corresponding execution of glEnd.
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