Gl.DepthFunc (gb.opengl)
Static Sub DepthFunc ( Function As Integer )
Specify the value used for depth buffer comparisons.
Parameters
- func
-
Specifies the depth comparison function.
Symbolic constants
Gl.NEVER,
Gl.LESS,
Gl.EQUAL,
Gl.LEQUAL,
Gl.GREATER,
Gl.NOTEQUAL,
Gl.GEQUAL, and
Gl.ALWAYS are accepted.
The initial value is Gl.LESS.
Description
Gl.DepthFunc specifies the function used to compare each incoming pixel depth value
with the depth value present in the depth buffer.
The comparison is performed only if depth testing is enabled.
(See
Gl.Enable and
Gl.Disable of Gl.DEPTH_TEST.)
func specifies the conditions under which the pixel will be drawn.
The comparison functions are as follows:
- Gl.NEVER
-
Never passes.
- Gl.LESS
-
Passes if the incoming depth value is less than the stored depth value.
- Gl.EQUAL
-
Passes if the incoming depth value is equal to the stored depth value.
- Gl.LEQUAL
-
Passes if the incoming depth value is less than or equal to
the stored depth value.
- Gl.GREATER
-
Passes if the incoming depth value is greater than the stored depth value.
- Gl.NOTEQUAL
-
Passes if the incoming depth value is not equal to the stored depth value.
- Gl.GEQUAL
-
Passes if the incoming depth value is greater than or equal to
the stored depth value.
- Gl.ALWAYS
-
Always passes.
The initial value of
func is Gl.LESS.
Initially, depth testing is disabled. If depth testing is disabled or if no
depth buffer exists, it is as if the depth test always passes.
Notes
Even if the depth buffer exists and the depth mask is non-zero, the
depth buffer is not updated if the depth test is disabled. In order to
unconditionally write to the depth buffer, the depth test should be enabled
and set to
Gl.ALWAYS.
Errors
Gl.INVALID_ENUM is generated if
func is not an accepted value.
Associated Gets
Gl.Get with argument Gl.DEPTH_FUNC
Gl.IsEnabled with argument Gl.DEPTH_TEST
See also
See original documentation on OpenGL website