code: func StencilOpSeparate(face uint32, sfail uint32, dpfail uint32, dppass uint32) {
  	C.glowStencilOpSeparate(gpStencilOpSeparate, (C.GLenum)(face), (C.GLenum)(sfail), (C.GLenum)(dpfail), (C.GLenum)(dppass))
  }
docs: // set front and/or back stencil test actions