Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> writes: >> +INPUT_PROP_POINTER: >> +------------------ >> +There is a one to one mapping between the device coordinates and >> +screen coordinates. > > This is not correct as touchpads fall firmly into INPUT_PROP_POINTER > land and certainly do not have 1:1 relationship between on-screen and > device coordinates. > >> This property only has meaning for non-touch based >> +input such as a pen or an eraser. A drawing tablet would have this property >> +set. > > Wacom Bamboo touch can be said is touch based but still is a pointer > device. Basically pointer device is one that requires use of an > on-screen pointer to reflect user's movement while with direct devices > touching object itself serves as a pointer to the user. So, does the above mean something like this? device I_P_POINTER I_P_DIRECT 1:1 =========================================== tablet present present yes touchpad present missing no touchscreen missing present yes <impossible> missing missing no Jussi Pakkanen <jussi.pakkanen@xxxxxxxxxxxxx> writes: > +INPUT_PROP_POINTER: > +------------------ > + > +There does not exist a one to one mapping between the device > +coordinates and screen coordinates. If I understood Dmitry right, the existence of a 1:1 mapping has nothing to do with a device being I_P_POINTER: the presence of this property means that an on-screen pointer is required to reflect the user's movement. (In practice, non direct devices probably always require a pointer, or maybe I just lack imagination.) > This property only has meaning for non-touch based input such as a pen > or an eraser. And what's its meaning then? Sorry, maybe it's just me, but I don't understand such sentences. In my understanding, a device either carries a property or not; the meaning of a given property is always the same, and it's the very role of the documentation to define these meanings. > +INPUT_PROP_DIRECT: > +------------------ > + > +The device coordinates can be directly mapped to screen coordinates Cool. > +(i.e. the opposite of INPUT_PROP_POINTER) Not cool, according to my interpretation of Dmitry's previous review: see above. > This property only has meaning for touch-based input. See my other paragraph above. Jussi, please don't take this personal! I'm no expert of this, and I'm not a native English speaker. Still I think documentation should be clear even for such dummies like me, that's why I chimed in. Hopefully it isn't considered bikeshedding. -- Thanks, Feri. -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
