glDepthFunc(3G)glDepthFunc(3G)NAMEglDepthFunc - specify the value used for depth buffer comparisons
SYNOPSIS
void glDepthFunc(
GLenum func );
PARAMETERS
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.
DESCRIPTIONglDepthFunc() 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 glEn‐
able() and glDisable() of GL_DEPTH_TEST.)
func specifies the conditions under which the pixel will be drawn. The
comparison functions are as follows: Never passes. Passes if the
incoming depth value is less than the stored depth value. Passes if
the incoming depth value is equal to the stored depth value. Passes if
the incoming depth value is less than or equal to the stored depth
value. Passes if the incoming depth value is greater than the stored
depth value. Passes if the incoming depth value is not equal to the
stored depth value. Passes if the incoming depth value is greater than
or equal to the stored depth value. 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 GETSglGet() with argument GL_DEPTH_FUNC
glIsEnabled() with argument GL_DEPTH_TEST
SEE ALSOglDepthRange(3)(), glEnable(3), glPolygonOffset(3)glDepthFunc(3G)
