[Libff-devel] Re: [Libff-kernel] Wingman Force 3D in linux, not only questions.

[<py...@lo...>]

Hi

Thanks, I started playing with it. 

> My advice:
> 1. look at the usb data when nothing happens (no effect played, joystick
> not moving)

Well, I get some "init", than nothing happens.

> 2. look at the data when the joystick moves

> 3. Identify packets describing the state of the stick. Those are not the
> packets you are interested in.

Well it's lots of data, trying to find a method for not (at least not fully) 
manual searchigh through URB-s, however joystick after startup emulates 
spring, dou You remember (or have it written) if there are any force - 
related information sent for this reason ?

> 4. look at the data when effects are played

I thought there was some effect tester/modeller with directX (direct input). I 
guess I was wrong (at least about directx9c), do You know anything (but plain 
C programs I could write) that allows playing custom effects ?

> 5. Identify the packets that were not there in 2 and 1. Those are
> probably force-feedback packets
> 6. Change the parameters of the effects, look at the data, guess what
> bytes encode what parameters

Well, I'll try;).


> I've already done 1 to 5, I was trying to do 6 for spring/friction
> effects when my stick stopped working.
> The packets for condition effects use the same pipe as packets for
> constant force, they have a similar structure as well.
>
> You might want to install cygwin so that you get access to grep, sort...
> they are usefull to sort and filter large anounts of data automatically.
>


1. Well, I've done some sniffing fo far but results are not yet very clear, 
I'll have to find some reasonable method not using logitech - provided tester 
(since it does not generate custom effects - i guess - just shots, crashes 
and so on).
Is there a ready-made tool to send custom packets/sequences of packets to the 
device, or I will have to write my own one ? (preferably linux one - not to 
interfere with windows drivers which seem to go crazy with just the sniffer).

Correct me if I'm wrong, I started looking through the linux driver, to find 
(at leas more or less what to look for). In the kernel (source), in 
hid-lgff.c what stores effects is called "private". It's declared as a void 
pointer in input.h and it is allocated as lgff_devices structure in 
hid-lgff.c. When/(or maybe if) I find something useful I should fill this 
structure's fields with propper data (like it is done int 
privete->constant->field[0]...). 
lgff_device has (among other) elements: constant and rumble, but what about 
ramp, sine and so on? are they "struct lgff_effect effects[8]" ? (or at the 
moment there is just no room for them ? Well, I'm just starting to look 
through the source code to find out what and how is done, so my questions 
might be quite silly for now ;) )

Michal