glDepthFunc - specify the value used for depth buffer comparisons
void glDepthFunc( GLenum func )
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 default value is GL_LESS.
glDepthFunc 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 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 z value is less than the stored z value. GL_EQUAL Passes if the incoming z value is equal to the stored z value. GL_LEQUAL Passes if the incoming z value is less than or 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 default value of func is GL_LESS. Initially, depth testing is disabled.
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.
glGet with argument GL_DEPTH_FUNC glIsEnabled with argument GL_DEPTH_TEST
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Fri Dec 6 11:18:03 EST 1996
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