Specifies the function used for depth buffer comparisons.
OpenGL C bindings library: libGL.a
void glDepthFunc(GLenum function)
|function||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 function is GL_LESS.|
The glDepthFunc subroutine 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.)
The function parameter specifies the conditions under which the pixel will be drawn. The comparison functions are as follows:
|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.|
The default value of function is GL_LESS. Initially, depth testing is disabled.
|GL_INVALID_ENUM||function is not an accepted value.|
|GL_INVALID_OPERATION||The glDepthFunc subroutine is called between a call to glBegin and the corresponding call to glEnd.|
Associated gets for the glDepthFunc subroutine are as follows. (See the glGet subroutine for more information.)
glGet with argument GL_DEPTH_FUNC
glIsEnabled with argument GL_DEPTH_TEST.
|/usr/include/GL/gl.h||Contains C language constants, variable type definitions, and ANSI function prototypes for OpenGL.|
The glBegin or glEnd subroutine, glDepthRange subroutine, glEnable or glDisable subroutine, glPolygonOffset subroutine, glPolygonOffsetEXT subroutine.