type
    Rectangle_t = unknown 8,

    RegionRectangle_t = struct {
	*RegionRectangle_t rr_Next, rr_Prev;
	Rectangle_t rr_bounds;
    },

    Region_t = struct {
	Rectangle_t rg_bounds;
	*RegionRectangle_t rg_RegionRectangle;
    };

extern
    AndRectRegion(*Region_t rg; *Rectangle_t r)void,
    AndRegionRegion(*Region_t rg1, rg2)bool,
    ClearRectRegion(*Region_t rg; *Rectangle_t r)bool,
    ClearRegion(*Region_t rg)void,
    DisposeRegion(*Region_t rg)void,
    NewRegion()*Region_t,
    OrRectRegion(*Region_t rg; *Rectangle_t r)bool,
    OrRegionRegion(*Region_t rg1, rg2)bool,
    XorRectRegion(*Region_t rg; *Rectangle_t r)bool,
    XorRegionRegion(*Region_t rg1, rg2)bool;