Brendan Shanks (@bshanks) commented about dlls/winemac.drv/macdrv_cocoa.h:
extern void macdrv_set_cocoa_window_frame(macdrv_window w, const CGRect* new_frame); extern void macdrv_get_cocoa_window_frame(macdrv_window w, CGRect* out_frame); extern void macdrv_set_cocoa_parent_window(macdrv_window w, macdrv_window parent); -extern void macdrv_window_set_color_image(macdrv_window w, CGImageRef image, CGRect rect, CGRect dirty); -extern void macdrv_window_set_shape_image(macdrv_window w, CGImageRef image); +extern void macdrv_window_set_io_surface(macdrv_window w, IOSurfaceRef image, CGRect rect, CGRect dirty); +extern void macdrv_window_shape_changed(macdrv_window w, int has_shape);
`has_shape` can be a `bool`