Arduino + Processing oscilloscope

import processing.serial.*;
import java.awt.event.*;

Serial port;
byte[] values;



int threshold = 60;
boolean save = false;
int zoom = 4;
int offsetx = 0;
int lastxPos = -1;
boolean isgoing = false;
int lasts = 0;
int lastxOffset = 0;
byte lastsample = 0;
long last5ks = 0;
long allsamples = 0;
long time = 1000;
boolean capture = true;
boolean zorth = false;
boolean oforbox = false;
int boxstart = 0;
int boxend = 0;


void setup()
{
  frame.setResizable(true);
  size(displayWidth -100, displayHeight - 100);
  port = new Serial(this, Serial.list()[Serial.list().length - 1], 1000000);    //adjust to your COM-Port
  values = new byte[400000000];
  addMouseWheelListener(new MouseWheelListener() {
    public void mouseWheelMoved(MouseWheelEvent mwe) {
      mouseWheel(mwe.getWheelRotation());
    }
  }
  );

  smooth();
  thread("Sample");
}


void mouseDragged()
{
  if (oforbox)
  {
    boxend = mouseX;
  }
  else
  {
    offsetx = lastxOffset + ((mouseX - lastxPos) * zoom);
    if (offsetx < 0)
      offsetx = 0;
    if ((offsetx) > lasts)
      offsetx = lasts ;
  }
}

void mousePressed()
{
  if (oforbox)
  {
    boxstart = mouseX;
    boxend = mouseX;
  }
  else
  {
    lastxPos = mouseX;
    lastxOffset = offsetx;
  }
}

void keyPressed() //+++++++++++++++++++++++++++++++
{
  if (key == 's'||key == 'S')
  {
    saveFrame();
  }

  if (key == 'c'||key == 'C')
  {
    capture = !capture;
  }

  if (key == CODED && keyCode == CONTROL)
  {
    zorth = true;
  }

  if (key == 'b'||key == 'B')
  {
    oforbox = !oforbox;
  }
  if (key == 'r'||key == 'R')
  {
    lasts = 0;
    offsetx = 0;
  }
}
void keyReleased()
{
  if (key == CODED && keyCode == CONTROL)
  {
    zorth = false;
  }
}

void mouseWheel(int delta) {
  if (zorth)
  {
    threshold -= delta * 4;
    if (threshold > 255)
      threshold = 255;
    if (threshold < 1)
      threshold = 1;
  }
  else
  {
    int oldzoom = zoom;
    zoom += delta;
    if (zoom <= 0)
      zoom = 1;
    if (zoom != oldzoom)
    {
      if (zoom < oldzoom)
      {
        offsetx += (width - mouseX);
      }
      else
      {
        offsetx -= (width - mouseX);
      }
    }
    if (offsetx < 0)
      offsetx = 0;
    if ((offsetx) > lasts)
      offsetx = lasts ;
  }
}

void Sample()
{
  int rbl = 4000;
  int rs = 0;
  byte[] ring = new byte[rbl];
  int rbp = 0;

  while (true)
  {
    while (!capture)
    {
      while (port.available () < 1) {
      }
      lastsample = (byte)port.read();
    }
    if (allsamples >= 20000)
    {
      allsamples = 0;
      time = millis() - last5ks;
      last5ks = millis();
    }
    allsamples ++;

    while (port.available () < 1) {
    }
    int lastsamplei = port.read();
    if (lastsamplei >= 0)
    {
      lastsample = (byte)lastsamplei;

      if (lastsamplei > threshold)
      {
        rs = 4000;
      }

      if ( rs-- > 0)
      {

        if (!isgoing)
        {
          for (int i = rbp; i < (rbp + rbl); i++)
          {
            if (i >= rbl)
              values[lasts++] = ring[i - rbl];
            else
              values[lasts++] = ring[i];
          }
          isgoing = true;
        }
        values[lasts++] = lastsample;
      }
      else
      {
        ring[rbp++] = lastsample;
        if (rbp >= rbl)
        {
          rbp = 0;
        }
        isgoing = false;
      }
    }
  }
}

int Yval(int vale) {
  vale *= (height - 140) / 255.0 ;
  vale += 120;
  return Y(vale);
}

int Y(int valu)
{
  return height - valu;
}

void draw()
{

  background(0);


  stroke(#000060);

  int y1 = Yval(threshold) - 15;
  if (y1 < 1)
    y1 = 1;
  fill(#000040);

  triangle(1, y1, 1, Yval(threshold) + 15, 15, Yval(threshold)); //THRESHOLD

  fill(30);
  stroke(30);
  rect(0, Y(120), width, 120);// BOTTOM


  fill(#005000);
  stroke(#005000);
  int l = lastsample;
  if (l < 0) l += 256;
  rect(0, Yval(l), 20, (int)(l / 255.0f * (height - 120)) - 1); //CURRENT LEVEL

  stroke(#002000);




  for (int i = width - 100; i > 0; i -= 100)
  {
    for (int y = 1; y + 120 < height; y+= 40)
    {
      line(i, Y(y + 120), i, Y(y + 130));
    }
  }


  fill(#AAAAFF);

  textSize(14);
  text("samples in memory", 20, height - 45);
  text("bytes available", 20, height - 90);



  text("samples/s", 170, height - 45);
  text("ms/div", 170, height - 90);


  text("samples/div", 350, height - 45);


  if (oforbox)
  {
    text("selected samples", 550, height - 45);
    text("selected ms", 550, height - 90);
    text("Period  > Hz", 700, height - 90);
  }


  textSize(20);

  text(lasts, 20, height - 25);
  text(port.available(), 20, height - 70);



  text(20000000/time, 170, height - 25);          //s/s
  text((    Float.toString( (float)(100 * zoom) /   (20000000/time)   * 1000)), 170, height - 70); //msdiv


  text(100 * zoom, 350, height - 25);            //sdiv


  if (oforbox)
  {
    text(abs((boxstart - boxend) * zoom), 550, height - 25); //sbox
    text(abs(boxstart - boxend) * zoom /   (20000.0/time), 550, height-70);
    text(1000/(abs(boxstart - boxend) * zoom /   (20000.0/time)), 700, height-70);
  }



  if (capture)
  {
    text("capture: on", width - 200, height - 25);
  }
  else
  {
    text("capture: off", width - 200, height - 25);
  }
  fill(#808000);
  if (oforbox)
  {
    {
      int x1 = boxstart - 15;
      if (x1 < 1)
        x1 = 1;
      if (x1 > width)
        x1 = width;
      int x2 = boxstart + 15;
      if (x2 < 1)
        x2 = 1;
      if (x2 > width)
        x2 = width;


      triangle(x1, height - 120, x2, height - 120, boxstart, height - 135); //BOXSTART
      line(boxstart, height - 120, boxstart, 1);
    }
    {
      int x1 = boxend - 15;
      if (x1 < 1)
        x1 = 1;
      if (x1 > width)
        x1 = width;
      int x2 = boxend + 15;
      if (x2 < 1)
        x2 = 1;
      if (x2 > width)
        x2 = width;


      triangle(x1, height - 120, x2, height - 120, boxend, height - 135); //BOXEND
      line(boxend, height - 120, boxend, 1);
    }
  }


  stroke(#00FFFF);



  if (lasts > 0)
  {
    int valpos = lasts - offsetx;
    int lastval = values[valpos];

    int zoomstep = zoom / 4;
    if (zoomstep < 1)
      zoomstep = 1;


    for (int i = width - 1; i > 0; i--)
    {
      for (int c = 0; c < zoom; c+= zoomstep)
      {
        if (valpos - c < 0)
        {
          return;
        }
        int val = values[valpos - c];
        if (val < 0)
          val += 256;
        line(i + 1, Yval(lastval), i, Yval(val));
        lastval = val;
      }
      valpos -= zoom;
    }
  }
}

/*


 const unsigned char PS_16 = (1 << ADPS2);
 const unsigned char PS_32 = (1 << ADPS2) | (1 << ADPS0);
 const unsigned char PS_64 = (1 << ADPS2) | (1 << ADPS1);
 const unsigned char PS_128 = (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0);


 void setup()
 {
 Serial.begin(1000000);
 pinMode(A0, INPUT);

 ADCSRA &= ~PS_128;
 ADCSRA |= PS_16;
 }

 void loop()
 {
 Serial.write(analogRead(A0) >> 2);
 }
 */