glDepthFunc

The glDepthFunc function specifies the value used for depth-buffer comparisons.

void glDepthFunc(
  GLenum func);

• func
  Specifies the depth-comparison function. The following symbolic constants are accepted.
  Expand table

  Symbolic Constant	Meaning
  GL_NEVER	Never passes.
  GL_LESS	Passes if the incoming z value is less than the stored z value. This is the default value.
  GL_LEQUAL	Passes if the incoming z value is less than or equal to the stored z value.
  GL_EQUAL	Passes if the incoming z value is equal to the stored z value.
  GL_GREATER	Passes if the incoming z value is greater than the stored z value.
  GL_NOTEQUAL	Passes if the incoming z value is not equal to the stored z value.
  GL_GEQUAL	Passes if the incoming z value is greater than or equal to the stored z value.
  GL_ALWAYS	Always passes.

The glDepthFunc function specifies the function used to compare each incoming pixel z value with the z value present in the depth buffer. The comparison is performed only if depth testing is enabled. (See glEnable with the argument GL_DEPTH_TEST.)

Initially, depth testing is disabled.

The following functions retrieve information related to glDepthFunc:

glGet with argument GL_DEPTH_FUNC

glIsEnabled with argument GL_DEPTH_TEST

The following are the error codes generated and their conditions.

**  Windows NT/2000:** Requires Windows NT 3.5 or later.
**  Windows 95/98:** Requires Windows 95 or later. Available as a redistributable for Windows 95.
**  Header:** Declared in Gl.h.
**  Library:** Use Opengl32.lib.

glBegin, glDepthRange, glEnable, glEnd, glGet, glIsEnabled