gtk:gl-area-has-stencil-buffer (object)

object -- a gtk:gl-area widget
setting -- a boolean whether the widget will allocate and enable a stencil buffer

The accessor for the has-stencil-buffer slot gets or sets whether the area has a stencil buffer.

If setting is true the widget will allocate and enable a stencil buffer for the target framebuffer. Otherwise there will be none.