Test simple Leap Motion gesture recognition with node.js

leap_gesture_test.js

var _ = require('underscore')
var Leap = require('leapjs')


/*** Decompose X, Y, Z vector to simple direction */
var getDirection = function(vector) {

  // Only do this if vector is defined and has length 3
	if (vector && vector.length == 3) {

		// Find out which axis has largest absolute value (e.g. major direction component)
		var absVector = _.map(vector, Math.abs); 
		var axis = absVector.indexOf(Math.max.apply(null, absVector));

		// Return a word based on the axis and the sign of the value in that axis
		return [['left','right'],['down', 'up'],['in','out']][axis][vector[axis] > 0 ? 1 : 0]
	}
};


var controller = new Leap.Controller({enableGestures: true});

// Handle a frame and print direction and state of a swipe gesture
controller.on('frame', function (f) {
	if(f.gestures.length > 0) {
		if(f.gestures[0].type == 'swipe') {
			console.log('swipe: ' + getDirection(f.gestures[0].direction) + ' ' + f.gestures[0].state);
		}
	}
});

// Go!
controller.connect();

//EOF