> Nor can you build an interface where a swipe in this direction does that, but if it's two degrees farther counterclockwise, it does something else entirely
Two degrees, of course not. But https://en.wikipedia.org/wiki/Pie_menu are a thing. Swype text input is nowhere near the best we can do, it does not have context-driven feedback of any sort. The most annoying issue with touchscreen-only input, IME, is actually recovering from input errors, and (relatedly) confirmation for irreversible actions. Low-level environments for "modding" Android devices get this right - every destructive action always requires confirmation by issuing a full swipe, and it's only destructive actions that require this. Of course, porting this paradigm to more traditional environments (such as typical GUI applications) would require quite a bit of work.
Two degrees, of course not. But https://en.wikipedia.org/wiki/Pie_menu are a thing. Swype text input is nowhere near the best we can do, it does not have context-driven feedback of any sort. The most annoying issue with touchscreen-only input, IME, is actually recovering from input errors, and (relatedly) confirmation for irreversible actions. Low-level environments for "modding" Android devices get this right - every destructive action always requires confirmation by issuing a full swipe, and it's only destructive actions that require this. Of course, porting this paradigm to more traditional environments (such as typical GUI applications) would require quite a bit of work.