[CM] Receiving OSC

[Kjetil S. Matheussen]

On Thu, 23 Oct 2008, Kjetil S. Matheussen wrote:

>
> I'm no expert in OSC, but I think using a C library, such as
> liblo would be easier to use in Snd than OscPack,
> which is a C++ library.
>
> Here's an example client:
> http://liblo.svn.sourceforge.net/viewvc/liblo/trunk/examples/example_client.c?revision=121&view=markup
>
> Using eval-c, the example (up to the first "send" command only
> and without the "blob"), can be written like this:
>
> (eval-c-add-int-type "int32_t")
> (eval-c "-llo"
>         "#include <lo/lo.h>"
>         (proto->public
>          "lo_address lo_address_new(const char *host, const char *port);
>           int lo_send_message (lo_address targ, const char *path, lo_message msg);
>           lo_message lo_message_new (void);
>           void lo_message_free (lo_message m);
>           void lo_message_add_int32 (lo_message m, int32_t a);
>           void lo_message_add_float (lo_message m, float a);
>           void lo_message_add_string (lo_message m, const char *a);"))
>
> (define t (lo_address_new #f "7770"))
>
> (define message (lo_message_new))
>
> (lo_message_add_float message 0.12345678)
> (lo_message_add_float message 23.0)
>
> (define result (lo_send_message t "/foo/bar" message))
>


A convenient function:


(define (osc_send host port path . args)
   (define address (lo_address_new host (if (string? port)
                                            port
                                            (number->string port))))
   (define message (lo_message_new))
   (for-each (lambda (arg)
               (cond ((and (number? arg)
                           (integer? arg))
                      (lo_message_add_int32 message arg)))
                     ((number? arg)
                      (lo_message_add_float message arg))
                     ((string? arg)
                      (lo_message_add_string message arg))
                     (else (error "unkown arg" arg))))
             args)
   (let ((res (lo_send_message address path message)))
     (lo_message_free message)
     res))

(osc_send t #f 7770 "/foo/bar" 5.2 9.4 "hello" 9234/234)
;; ( #f means local host )