node-red-contrib-leap-motion/leapposition.js

Node-Red nodes for leap motion

var Leap=require('leapjs');
var RED = require(process.env.NODE_RED_HOME+"/red/red");
module.exports = function (RED) {
  function Constructor (config) {
    RED.nodes.createNode(this, config);
    var node = this;
    var direction="?";
    var pastDirection;
    var controller = Leap.loop({enableGestures: true}, function(frame){
      pastDirection = direction;
      if (frame.hands.length === 0) { //No hand detected
        direction = 'NOHAND';
      } else if (frame.hands.length > 0) {
        for (var i = 0; i < frame.hands.length; i++) {
          var hand = frame.hands[0];
          var position = hand.palmPosition;
          var previousFrame = controller.frame(1);

          if (position[0] < 80 &&  position[0] > -80 && position[2] < 80 &&  position[2] > -80 ){
             direction = 'CENTER'; //The hand is above the leap
          }else{
            if (position[0] > 80 ){
              direction = 'RIGHT';
            }
            if (position[0] < -80 ){
              direction = 'LEFT';
            }
            if (position[2] > 80 ){
              direction = 'BACKWARD';
            }
            if (position[2] < -80 ){
              direction = 'FORWARD';
            }
          }
        }
      }
      if(pastDirection != direction){ //Send one message when the hand have a new position
       switch (direction) {
         case 'LEFT':
          node.send({payload:"left"});
         break;
         case 'RIGHT':
          node.send({payload:"right"});
         break;
         case 'FORWARD':
          node.send({payload:"forward"});
         break;
         case 'BACKWARD':
          node.send({payload:"backward"});
         break;
         case 'CENTER':
          node.send({payload:"center"});
         break;
         case 'NOHAND':
          node.send({payload:"nohand"});
         break;
       }
     }
    });
  }
  RED.nodes.registerType('leapposition', Constructor)
}