On Tue, Jul 1, 2014 at 10:47 AM, Ping Cheng <[email protected]> wrote: > On Mon, Jun 30, 2014 at 1:03 AM, Dmitry Kazakov <[email protected]> wrote: >> Hi, all! >> >> I'd like to add about mapping of the tablet input. >> >> In XInput one can assign a matrix transfromation for each tablet device, >> which is exactly what people need. > > If we support matrix transformation in libinput/Wayland, all "tablet > to screen" mapping requests would be met, including my mapping to > windows. > >> The usual usecase is the following: >> >> A painter has a display + intuos tablet + cintiq. The external tablet is >> mapped to the external display, the Cintiq, obviously, is mapped into itself >> [0]. The external display can be (and probably will be) rotated on 90deg to >> have Portrait orientation. >> >> Right now all the mappings for such configuration can be achieved with >> xsetwacom/xinput calls. >> >> >> [0] - No painters I know use mappings to the specific window. > > You work with painters directly. I believe you know more of what they > use. I am only a driver developer. I can not draw a straight line on > paper or on computer ;). > >> Mode switches are troublesome. > > My mapping/display toggle/mode toggle experience was from animation > artists' requests. What kind of trouble do you usually see from mode > switch/toggle? I want to see if we have a solution.
From discussions in other threads, I feel my terms (mapping, display toggle, mode toggle) may not clear to some of you. Mapping means to map a specific tablet area to a specific display area. A common use case would be to map whole tablet to a screen/ whole desktop; Mode toggle is a function to switch between absolute to relative motion mode; Display toggle is a function to switch among screens and the whole desktop, in multi-monitor setup. Ping > Thank you for sharing your ideas. We desperately needed feedback like yours. > > Ping > >> On Mon, Jun 30, 2014 at 11:41 AM, Dmitry Kazakov <[email protected]> wrote: >>> >>> Hi, all! >>> >>> I will try to answer all your emails in one post. >>> >>> 1) Tablet vs. Touch. Basically what I am talking about is *not* touch >>> arbitration and palm recognition. The Wacom driver itself blocks all the >>> touch events when the stylus is in the proximity, so it performs the >>> necessary arbitration. What we need is to block several kinds of actions >>> (read "tools") when the user uses touch and unblock them when the user works >>> with stylus or mouse. An exact usecase: we need to allow the user to >>> zoom/pan on the canvas with his fingers, but at the same time real painting >>> with fingers must be prohibited (it disturbs the painters). Right now it is >>> almost impossible, because we get no touch events, and instead get >>> synthesized MousePress/Release/Move events for finger actions, which are >>> indistinguishable from real mouse events. >>> >>> 2) Buttons vs Tablet Press. Well, to tell you the truth we are not >>> interested in whether the stylus touched the surface of not. At all. The >>> stylus has 3 button: the tip itself, and two buttons. These three buttons >>> can be remapped with the driver (xsetwacom) to any X11 button the user >>> wants. Therefore, I have absolutely no interest in TabletTouch/TabletRelease >>> if the only thing they tell me that the stylus has touched the surface of >>> the tablet with the stylus or not. What I really need is the >>> TabletButtonPress/Release event, which tells me: >>> >>> 1) Which button (of the three) is pressed >>> 2) Exact position of the stylus >>> 3) Pressure, Tilt, Z-coordinate if available (might be zero/unit for some >>> of the buttons) >>> >>> The situation is getting even worse if you look at the feature which >>> Windows' Wacom driver has (I'm not sure whether this feature is available in >>> X11 Wacom driver, but it is highly requested by the painters). On Windows >>> the buttons on the stylus can be switched into "modifier" mode. That is >>> pressing the button doesn't produce a real button event. You need to press >>> the stylus button, and then touch the surface of the tablet with the tip: >>> only then the app will get mouse button click (right or middle button >>> usually). If this feature will ever be implemented in X11 Wacom driver >>> (which is quite desirable), your protocol with TabletTouch/Press will not >>> work. Please check Wintab protocol docs for more info, specifically, >>> CSR_SYSBTNMAP attributes [0] >>> >>> 3) Axes resolution. Yes, it is perfectly ok to have a separate function >>> which tells the physical limits of the axis. What I wanted to say is that >>> min_value/max_value attributes, which are reported by XInput are not enough. >>> For rotation I also need to know the mapping of the coordinate system origin >>> and it's direction (clockwise/counterclockwise). >>> >>> PS: >>> Please keep me in CC, I'm having troubles with keeping up with the traffic >>> in this mailing list. >>> >>> >>> [0] - http://www.wacomeng.com/windows/docs/Wintab_v140.htm >>> >>> >>> >>> On Fri, Jun 27, 2014 at 6:53 AM, Jason Gerecke <[email protected]> >>> wrote: >>>> >>>> On Wed, Jun 25, 2014 at 5:50 PM, Peter Hutterer >>>> <[email protected]> wrote: >>>> > Replying to three emails at once here to keep the thread a bit more >>>> > managable. >>>> > >>>> > On Wed, Jun 25, 2014 at 01:38:22PM -0700, Jason Gerecke wrote: >>>> >> On Wed, Jun 25, 2014 at 12:38 AM, Lyude <[email protected]> wrote: >>>> >> > On Wed, 2014-06-25 at 11:06 +0400, Dmitry Kazakov wrote: >>>> >> >> Hi, all! >>>> >> >> >>>> >> >> >>>> >> >> I am a developer from Krita painting application team. We recently >>>> >> >> did >>>> >> >> quite much work on incorporating better tablet support in Krita. I >>>> >> >> have several comments about your proposal of the tablet protocol >>>> >> >> (sorry for nor replying directly, since I wasn't subscribed to the >>>> >> >> list before). >>>> >> > >>>> >> > Benjamin commented on this as I was writing this e-mail, and I >>>> >> > figured I >>>> >> > should too: yes, it's awesome to see developers commenting on the >>>> >> > protocol. A lot of the quirks around this protocol are going to be >>>> >> > difficult to see without the help of people who have programmed on >>>> >> > the >>>> >> > client side of things as opposed to the compositor side of things. >>>> >> > So >>>> >> > yes, your input is very much appreciated and I thank you for it! >>>> >> > >>>> >> >> >>>> >> >> 1) Axes. There should also be an axis for rotation of the stylus >>>> >> >> (Artpen) and Tangential Pressure (for the wheel of the Airbrush). >>>> >> >> >>>> >> >> 2) There is also Artpen type of stylus. In Qt it is called >>>> >> >> "Rotational >>>> >> >> Stylus". >>>> >> > >>>> >> > Don't worry, we haven't forgotten about these. These will eventually >>>> >> > be >>>> >> > added into the protocol. The reason why they're not in this draft is >>>> >> > because I'm doing this as my Google Summer of Code project, and as >>>> >> > such >>>> >> > I'm on a deadline and I have to focus on just getting the basics >>>> >> > done >>>> >> > first before I can focus on all of the other features. >>>> > >>>> > Our current approach, both in libinput and the WL protocol should make >>>> > these >>>> > additions little more than adding a couple of enum, so I think we're >>>> > good >>>> > here. >>>> > >>>> >> >> 3) Fingers. There is a complication in XInput2 right now, since >>>> >> >> touch >>>> >> >> enabled Wacom devices have a special Finger XInput2 device, which >>>> >> >> provides both interfaces: tablet and touch and therefore generates >>>> >> >> both types of events. Right now Qt5 still cannot handle it >>>> >> >> properly, >>>> >> >> but the work is in progress. From Krita point of view, the main >>>> >> >> usecase for us is to distinguish whether the user paints with a >>>> >> >> finger >>>> >> >> of with the stylus. Because most of the users prefer to disable >>>> >> >> painting with fingers and use it for gestures/UI only (yes, palm >>>> >> >> detection works with non-100% probability). >>>> >> > >>>> >> > Right now libinput handles the finger device as another touchpad, >>>> >> > since >>>> >> > that's usually what it is. Your use-case sounds perfectly valid >>>> >> > though, >>>> >> > but IMO a better approach would be to add something to the protocol >>>> >> > for >>>> >> > touchpads on wayland so that it can be known that they belong to a >>>> >> > tablet and provide any other sorts of data you might be need, so >>>> >> > programs like yours can treat them differently. >>>> > >>>> > Dmitry, are you talking about pen/touch arbitration, i.e. don't send >>>> > touch >>>> > events when the pen is in use. If so, that's definitely on the plan, we >>>> > need >>>> > it for touchpads (disable while typing feature), and we need it for the >>>> > pen/touch interference. >>>> > >>>> > This will be hidden away so you or event the compositor don't have to >>>> > worry >>>> > about it. >>>> > >>>> >> >> 4) Button Press/Release events should come in both cases: when the >>>> >> >> user clicks on the stylus' buttons and when the stylus touches the >>>> >> >> surface of the tablet. >>>> >> > >>>> >> > I'm not entirely sure that's a good idea. If I'm reading this right, >>>> >> > you >>>> >> > mean that additional button presses should be sent when the tool >>>> >> > touches >>>> >> > the surface of the tablet. [...] >>>> > >>>> > We're already sending out BTN_TOUCH when the tip touches the surface, >>>> > so I >>>> > think we're good here. Unless Dmitry was referring to something else. >>>> > >>>> > >>>> >> >> 6) It might be a good idea to define the physical properties of the >>>> >> >> axes. E.g. for tilt, rotation and tangential pressure. Afair, Wacom >>>> >> >> driver for XInput returns some not-very-obvious values right now. >>>> >> >> One >>>> >> >> would need to experiment to know what these numbers mean. >>>> >> > >>>> >> > We would all love for this to be the case I promise you, but >>>> >> > unfortunately it's not that simple for all of the axes. The distance >>>> >> > axis reports a seemingly meaningless value that can't be converted >>>> >> > to >>>> >> > millimeters very easily. That being said, I have come up with a few >>>> >> > ways >>>> >> > that we could actually convert it to millimeters, but this will have >>>> >> > to >>>> >> > wait until I've fulfilled the goals for my Google Summer of Code >>>> >> > Project >>>> >> > (unless anyone else wants to implement this in the mean time in >>>> >> > libinput >>>> >> > of course). >>>> >> > >>>> >> > I'll write up the method I've come up with for converting this wild >>>> >> > value to actual millimeters at some point when I get the chance. >>>> >> > >>>> >> While I'm interested in seeing what you've come up with, I would be >>>> >> very hesitant to integrate the code into libinput. We make *no* claims >>>> >> about the physical resolution or accuracy of the distance axis. I've >>>> >> seen the value change by more than 10 units just by switching to a >>>> >> different pen... There's absolutely nothing stopping us from >>>> >> introducing a tablet that invalidates any clever code you may come up >>>> >> with. >>>> > >>>> > yeah, I agree with Jason here, let's not pretend we have data we don't >>>> > have. >>>> > As much as I'd like to attach concrete physical information to all axes >>>> > we >>>> > can't (well, shouldn't) make it up. >>>> > >>>> > Short of keeping a database of each tablet with the offsets and ratios >>>> > to >>>> > convert distance values to mm I don't think this is doable, and I'm not >>>> > a >>>> > big fan of that either. >>>> > >>>> >> > As for the tilt axes of the tools, this is something that could be >>>> >> > represented in a more meaningful value. We could normalize it to a >>>> >> > number between 0 and 180°, so you can get the actual tilt in degrees >>>> >> > as >>>> >> > opposed to what we currently have. This is something we could pull >>>> >> > off >>>> >> > rather easily, I'll make sure to discuss this with my mentor >>>> >> > tomorrow. >>>> >> > >>>> >> Alternatively, I would suggest adding an e.g. >>>> >> `libinput_event_tablet_get_axis_resolution` function. To get a >>>> >> physical value, a caller would just multiply whatever this function >>>> >> returns for some axis by the current normalized unitless value for the >>>> >> same. I suggest this for a few reasons: it is a fairly standard way of >>>> >> doing things (HID, the kernel, and X all use the same system), is more >>>> >> efficient (callers working in your preferred unit [e.g. Qt] are spared >>>> >> doing the conversion but anyone else [e.g. GTK, EFL] will have to do a >>>> >> second conversion to a different unit), and provides a way of getting >>>> >> physical information for any axis (if we ever came out with a pen that >>>> >> accurately measured distance, you wouldn't need to change the >>>> >> semantics of how distance is reported or sacrifice the now-existant >>>> >> physical translation information). >>>> > >>>> > Jason: how accurate is tilt, and are applications actually using it as >>>> > angle or >>>> > just as normalized number anyway? >>>> > >>>> >>>> I can't find a mention of the accuracy in any public docs, so I'm a >>>> little hesitant to give numbers on the list. The spec sheet does show >>>> it to be accurate to a handful of degrees though. >>>> >>>> The second part is a little complicated to answer. Every tilt-enabled >>>> program I'm aware of uses the data to adjust the brush azimuth. The >>>> goal is to have the virtual brush angled to be parallel with the >>>> physical pen at all times. A few applications also calculate an >>>> altitude angle, deforming the brush from circular to increasingly >>>> eliptical as the pen becomes more horizontal. Qt and Android (and >>>> likely EFL based on current discussions) have APIs that specify angles >>>> in various physical forms: tilt-x/tilt-y in degrees, alt-az in >>>> radians, etc. GTK on the other hand provides normalized data, but >>>> neither provides resolution information nor information about what >>>> "normalized" means. Because of the resulting ambiguity, GIMP and >>>> Inkscape do their calculations on the assumption that [-1, 1] in GTK >>>> corresponds to [-180 degrees, +180 degrees] in the physical world. GTK >>>> actually does its normalization based on the device's min/max though >>>> (so [-64 degrees, +63 degrees] for our hardware) meaning that GIMP and >>>> Inkscape wind up calculating incorrect azimuth values. The results >>>> aren't _that_ wrong though; I'm not aware of anyone having noticed or >>>> filing a bug about it. >>>> >>>> tl;dr, Applications universally /try/ to use the physical angles. Not >>>> all succeed. >>>> >>>> Jason >>>> --- >>>> Now instead of four in the eights place / >>>> you’ve got three, ‘Cause you added one / >>>> (That is to say, eight) to the two, / >>>> But you can’t take seven from three, / >>>> So you look at the sixty-fours.... >>>> >>>> >> > As for tangential pressure, this is a term I've never actually heard >>>> >> > of >>>> >> > before. I don't know what the values from the tablet are supposed to >>>> >> > correspond to in regards to pressure, so I've added two of our >>>> >> > friends >>>> >> > at Wacom to the CC list help us out (I hope you two don't mind!) on >>>> >> > this. >>>> >> > (Jason and Ping, if you guys aren't on the list already, the >>>> >> > original >>>> >> > protocol this e-mail is discussing can be found here: >>>> >> > >>>> >> > http://lists.freedesktop.org/archives/wayland-devel/2014-June/015583.html >>>> >> > ) >>>> >> > >>>> >> > In regards to rotation and any other axes, I haven't had any contact >>>> >> > with these yet. So I can't really say much on them. >>>> > >>>> > Rotation exists on the mouse/lens cursor tool, but it's a calculation >>>> > based >>>> > on the tilt x/y axes. For us it'd just be one more axis. >>>> > >>>> > Cheers, >>>> > Peter >>>> > >>>> >> I'm not sure where the term "tangential pressure" came from, but it >>>> >> can refer either to the fingerwheel on the airbrush tool (expected to >>>> >> be used to control ink flow rate; value is basically [0, 1]) or the >>>> >> fingerwheel on the 4D Mouse tool (which is like a spring-loaded >>>> >> mousewheel that reports how far forward or backward from the neutral >>>> >> position the wheel is; value is basically [-1, 1]). >>>> >> >>>> >> Jason >>>> > >>> >>> >>> >>> >>> -- >>> Dmitry Kazakov >> >> >> >> >> -- >> Dmitry Kazakov _______________________________________________ wayland-devel mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/wayland-devel
