Andrew: Aha!  I was wondering how to keep track of which touch is which, did not realize you could get the id of the object as an integer and use that as a key (I've programmed in scheme forever, but learning objective-c now).  I was just passing the x and y of a single touch across, and ignoring multiple touches.  Thanks!  I would be curious to see the code. James: That sounds great.  I am wondering what your strategy is for exposing an objective-c object to scheme like that, as so far I have only been able to send basic data types (int, double etc) between c and scheme.  Something like keeping some reference to the c object and implementing the various methods in scheme? In particular, I would like to make a list of x,y pairs that get sent from the c event handler to the corresponding scheme function, is that possible?  I imagine there could be some way to construct scheme lists from c, but not sure how that could be done at the moment.  As I say, I am still learning the ropes around here. Thanks for the replies! - Ryan --- On Sun, 7/12/09, James Long <longster@gmail.com> wrote: From: James Long <longster@gmail.com> Subject: Re: [Gambit-iphone] Touch Translation To: "Andrew Andkjar" <andkjar@obtech.net> Cc: "Ryan Spangler" <patch_work8848@yahoo.com>, "gambit-iphone@iro.umontreal.ca" <gambit-iphone@iro.umontreal.ca> Date: Sunday, July 12, 2009, 11:54 AM Hey Ryan, I have not worked much on access to Touch events yet, and you're probably looking for specific FFI code as an example.  Andrew, it would be great if you could share your code! I was thinking of exposing access to the UITouch and other event objects so that you could benefit from the normal Cocoa API.  When I do this, I will share this code. Thanks, James On Sun, Jul 12, 2009 at 1:30 PM, Andrew Andkjar<andkjar@obtech.net> wrote: > In the iPhone app I'm developing I am currently traversing the set of touch > events in Objective-C and calling into touch-<began | moved | ended> > Gambit-C callbacks I've defined that take an integer touch id and x,y > coordinates.  Active touches are tracked in Scheme in a hash table keyed on > touch id.  This has been suiting my multi-touch tracking needs so far.  I'd > be happy to share some code if there's interest. >     'AA > On Jul 11, 2009, at 6:03 PM, Ryan Spangler <patch_work8848@yahoo.com> wrote: > > Hey all, > > I was looking into porting the touch events into gambit, but I am pretty new > to gambit and the c ffi specifically.  The touch events are somewhat > complex, taking an NSSet * and a UIEvent *.  From what I can tell, the NSSet > contains all current touch points (so if you have three fingers down, the > NSSet contains three touch points) and the UIEvent has a history of all the > touch points and where they have been since the first "touchesBegan" event, > though I am not sure of the specific structure of these objects yet.  I am > wondering what is the best way to translate these into scheme data > structures? > > Thanks for any guidance on this, and I also noticed that James was talking > about working on touch facilities as well.  Maybe we could join forces on > this?  Or maybe you are already done? > > - Ryan > > > _______________________________________________ > Gambit-iphone mailing list > Gambit-iphone@iro.umontreal.ca > https://webmail.iro.umontreal.ca/mailman/listinfo/gambit-iphone > > _______________________________________________ > Gambit-iphone mailing list > Gambit-iphone@iro.umontreal.ca > https://webmail.iro.umontreal.ca/mailman/listinfo/gambit-iphone > >