glDepthFunc(3) glDepthFunc(3)
NAME
glDepthFunc - specify the value used for depth buffer comparisons
C SPECIFICATION
void glDepthFunc( GLenum func )
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
glDepthFunc specifies the function used to compare each incoming pixel
depth value with the depth value present in the depth buffer. The com-
parison is performed only if depth testing is enabled. (See glEnable
and glDisable 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 dis-
abled. 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.
ERRORS
GL_INVALID_ENUM is generated if func is not an accepted value.
GL_INVALID_OPERATION is generated if glDepthFunc is executed between
the execution of glBegin and the corresponding execution of glEnd.
ASSOCIATED GETS
glGet with argument GL_DEPTH_FUNC
glIsEnabled with argument GL_DEPTH_TEST
SEE ALSO
glDepthRange(3), glEnable(3), glPolygonOffset(3)
glDepthFunc(3)
Mac OS X 10.6 - Generated Thu Sep 17 20:20:17 CDT 2009