node-ffi-mapper.js

// instructions:
// 1.) install node.js and npm
// 2.) put this file in a folder
// 3.) go to this folder in terminal, and install ffi and ref using 'npm install ...'
// 4.) execute by typing `node node-ffi-mapper.js`
//
// note: refers explicitly to libmapper-0.2.dylib so make sure it is on the path!

var ref = require('ref');
var ffi = require('ffi');

var go_on = true;

var mapper = ref.types.void;
var mapperPtr = ref.refType(mapper);
var mapperDevPtr = ref.refType(mapperPtr);
var mapperSigPtr = ref.refType(mapperPtr);
var mapperVoidPtr = ref.refType('void');

var libmapper = ffi.Library('libmapper-0.2', {
   'mdev_new': [mapperDevPtr, ['string', 'int', 'int']],
   'mdev_poll': ['int', [mapperDevPtr, 'int']],
   'mdev_add_output': [mapperSigPtr,   [mapperDevPtr, 'string',
                              'int', 'char', 'string', 
                              mapperVoidPtr, mapperVoidPtr]],
   'msig_update_int' : ['void', [mapperSigPtr, 'int']]
});

//var devPtrPtr = ref.alloc(mapperDevPtr);
console.log("init device...");
var devPtrPtr = libmapper.mdev_new("device", 0, 0);
if (devPtrPtr.isNull())
   console.log("Err!");
else
   console.log("created device");
var devPtr = devPtrPtr.deref();

console.log("adding output signal");

var minPtrPtr = ref.alloc('void');
var maxPtrPtr = ref.alloc('void');

var devSigPtr = libmapper.mdev_add_output(devPtrPtr, "test_sig", 1, 'i', "hz", minPtrPtr, maxPtrPtr);


var i = 0;
while (go_on) {
   console.log("update/poll...");
   libmapper.msig_update_int(devSigPtr, i++);
   libmapper.mdev_poll(devPtrPtr, 500);   
}

console.log("ok");