Method GL.glDepthFunc()

Method glDepthFunc

void glDepthFunc(int func)

Description

glDepthFunc 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 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 disabled. .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.

Parameter 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.

Throws

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.