Gldepthrange - HP b2600 Reference Manual

glDepthRange

glDepthRange: specify mapping of depth values from normalized device coordinates to
window coordinates.
C Specification
void glDepthRange(
Parameters
zNear
zFar
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 zNear be less than zFar.
Reverse mappings such as zNear = 1, and zFar = 0 are acceptable.
Errors
•
Associated Gets
glGet with argument GL_DEPTH_RANGE
See Also
glDepthFunc,
glPolygonOffset,
glViewport
Chapter 4
GLclampd zNear,
GLclampd zFar)
Specifies the mapping of the near clipping plane to window
coordinates. The initial value is 0.
Specifies the mapping of the far clipping plane to window coordinates.
The initial value is 1.
GL_INVALID_OPERATION is generated if glDepthRange is executed between the
execution of glBegin and the corresponding execution of glEnd.
D
glDepthRange
103