OpenGL Programming Guide: The Official Guide to Learning OpenGL, Version 4.3, Eighth Edition

OpenGL Transformations

To tell OpenGL where you want the near and far planes, use the glDepthRange() commands.

void glDepthRange(GLclampd near, GLclampd far);void glDepthRangef(GLclampf near, GLclampf far);

Sets the near plane to be near on the z axis and the far plane to far on the z axis. This defines an encoding for z-coordinates that’s performed during the viewport transformation. The near and far values represent adjustments to the minimum and maximum values that can be stored in the depth buffer. By default, they’re 0.0 and 1.0, respectively, which work for most applications. These parameters are clamped to lie within [0, 1].