ArrayList<PVector> history = new ArrayList<PVector>();

import processing.serial.*;
float[] portValues = new float[8];


Serial myPort;
String inString;

void setup() {                                                    //set up canves
  size(400,400);
  frameRate (30);
  rectMode(CENTER);
  background(225);

  myPort = new Serial(this, "/dev/cu.usbmodem1421", 9600);


  for(int i = 0; i<2; i++) {                                      //set inatial point
    PVector point = new PVector(425,550);
   history.add(point);

    portValues[i] = 0;
  }
}


void draw() {                                                    //finds last x and y positions and draws a line between them

  fill(0);
  strokeWeight(2);

  if (inString != null)
  {
    portValues = processSensorValues(inString);
  }

  float z = portValues[2]/3;

   float xx = map(portValues[0],-10,10,0,width);
   float yy = map(portValues[1],-10,10,0,height);

  if(portValues[3] == 1)
  {
  PVector point = new PVector(xx,yy);

  history.add(point);
  PVector newPt = history.get(history.size()-1);
  PVector oldPt = history.get(history.size()-2);

    line(oldPt.x,oldPt.y,newPt.x,newPt.y);
  }
  else if(portValues[3] == 0)
  {
  }

  println(inString);                                    //prints data
  }

  float[] processSensorValues(String valString) {      //uses tempture data for nothing, but helps process data

  String[] temp = new String[8];
  temp = split(valString,"\t");

  if(temp == null) {
    for(int i = 0; i<8; i++) {
      temp[i] = "0";
    }
  }

  float[] vals = new float[8];
  for(int i = 0; i<8; i++)
  {
    if(temp != null)
    {
      vals[i] = float(temp[i]);
    }

    else
    {
      vals[i] = 0;
    }

  }
  return vals;
}

void serialEvent(Serial p) {
  inString = myPort.readStringUntil(10);
}