glDepthRange function

Article
12/11/2020

The glDepthRange function specifies the mapping of z values from normalized device coordinates to window coordinates.

Syntax

void WINAPI glDepthRange(
   GLclampd zNear,
   GLclampd zFar
);

Parameters

zNear: The mapping of the near clipping plane to window coordinates. The default value is zero.
zFar: The mapping of the far clipping plane to window coordinates. The default value is 1.

Return value

This function does not return a value.

Error codes

The following error code can be retrieved by the glGetError function.

Name	Meaning
GL_INVALID_OPERATION	The function was called between a call to glBegin and the corresponding call to glEnd.

Remarks

After clipping and division by w, z -coordinates range from 0.0 to 1.0, corresponding to the near and far clipping planes. The glDepthRange function specifies a linear mapping of the normalized z-coordinates in this range to window z-coordinates. Regardless of the actual depth buffer implementation, window coordinate depth values are treated as though they range from 0.0 through 1.0 (like color components). Thus, the values accepted by glDepthRange are both clamped to this range before they are accepted.

The default mapping 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 zNear be less than zFar. Reverse mappings such as (1,0) are acceptable.

The following function retrieves information related to glDepthRange:

glGet with argument GL_DEPTH_RANGE

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	Gl.h
Library	Opengl32.lib
DLL	Opengl32.dll