AveragePointTracking.pde

// Daniel Shiffman
// Tracking the average location beyond a given depth threshold
// Thanks to Dan O'Sullivan
// http://www.shiffman.net
// https://github.com/shiffman/libfreenect/tree/master/wrappers/java/processing

import org.openkinect.*;
import org.openkinect.processing.*;

// Showing how we can farm all the kinect stuff out to a separate class
KinectTracker tracker;
// Kinect Library object
Kinect kinect;

int v1lastTime;
PVector v1lastPosition;
float velocity;

void setup() {
  size(640,520);
  kinect = new Kinect(this);
  tracker = new KinectTracker();
  
  // Initialize...
  v1lastTime = 0;
  velocity = 0;
  v1lastPosition = PVector(0, 0, 0);
}

void draw() {
  background(255);

  // Run the tracking analysis
  tracker.track();
  // Show the image
  tracker.display();

  // Let's draw the raw location
  PVector v1 = tracker.getPos();
  fill(50,100,250,200);
  noStroke();
  ellipse(v1.x,v1.y,20,20);

  // NEW
  // Calculate velocity
   
  if (v1LastTime != 0) {
    int elapsedTime = millis() - v1LastTime; 
    
    // Velocity is distance over time...    
    velocity = PVector.dist(v1, v1lastPosition) / elapsedTime;
    println("Velocity: " + velocity);
  }
   
  // Save for next frame
  v1LastTime = millis();  
  v1lastPosition = v1.get();


  // Let's draw the "lerped" location
  PVector v2 = tracker.getLerpedPos();
  fill(100,250,50,200);
  noStroke();
  ellipse(v2.x,v2.y,20,20);

  // Display some info
  int t = tracker.getThreshold();
  fill(0);
  text("threshold: " + t + "    " +  "framerate: " + (int)frameRate + "    " + "UP increase threshold, DOWN decrease threshold",10,500);
}

void keyPressed() {
  int t = tracker.getThreshold();
  if (key == CODED) {
    if (keyCode == UP) {
      t+=5;
      tracker.setThreshold(t);
    } 
    else if (keyCode == DOWN) {
      t-=5;
      tracker.setThreshold(t);
    }
  }
}

void stop() {
  tracker.quit();
  super.stop();
}