[PD] wacom usb tablet as controller ?

[Christian Klippel]

hi,

Am Mittwoch, 9. April 2003 07:18 schrieb Hans-Christoph Steiner:
> The problem with writing a generic event interface object is that the
> number of outlets would change for every device, so for example, if you
> wrote your patch for a mouse with a wheel, that would give you
> three outlets for the x, y, and wheel axes.  But then throw in a mouse
> with no wheel, and you'll get one less outlet, and your patch is broken.
>

huh ? sorry, but you are completely wrong with that.

exactly that is the reason the event interface exists.
you have uniform messages for every kind of (not only) hid input device, like 
mice, joysticks, keyboards, etc .....

and that is the reason i made "usbtablet" as object first, and no other 
"special" objects, but the the generic event object as this is enough.

you may want to take a look at http://www.frogmouth.net/hid-doco/x401.html
there you can see the input_event structure, and that is the only data you get 
from the event interface. that is :

struct input_event {
        struct timeval time;
        unsigned short type;
        unsigned short code;
        unsigned int value;
};

for mouse movement, it could be like type=EV_REL, code=REL_X, value=85 ...
for a tablet it could be type=EV_ABS, code=ABS_Y, value=19282 ....
or for a keybpard type=EV_KEY, code=KEY_SPACE, value=0 ....
or for the mouse wheel type=EV_REL, code=REL_WHEEL, value=12 ....

as you can see, you have only 3 outlets, or four if you want to have the 
timestamp as well.

it should be really easy to decode that output in a patch by route or select.
that avoids the redundancy of having multiple binary objects for more or less 
the same function. and, you dont need to add the input devices anywhere to 
access them, like with xinput. its simply a device file, thats it ...

greets,

chris