glStencilOpSeparate

Specifies whether front and/or back stencil state is updated. Three symbolic constants are valid: GL_FRONT , GL_BACK , and GL_FRONT_AND_BACK .

Specifies the action to take when the stencil test fails. Eight symbolic constants are accepted: GL_KEEP , GL_ZERO , GL_REPLACE , GL_INCR , GL_INCR_WRAP , GL_DECR , GL_DECR_WRAP , and GL_INVERT . The initial value is GL_KEEP .

Specifies the stencil action when the stencil test passes, but the depth test fails. dpfail accepts the same symbolic constants as sfail . The initial value is GL_KEEP .

Specifies the stencil action when both the stencil test and the depth test pass, or when the stencil test passes and either there is no depth buffer or depth testing is not enabled. dppass accepts the same symbolic constants as sfail . The initial value is GL_KEEP .