Input/Output Homework

Description
I have multiple lines being drawn at various lengths. Their colors depend on how much light I shine on the photocell. I used my last assignment as a template for this one.
 
Materials
1 - photocell
1 - arduino
1- 10k resistor
 
Code

import processing.serial.*;

PFont caption;

String portname = "/dev/tty.usbmodem1421"; // or "COM5"

Serial port;

String buf="";

int cr = 13;  // ASCII return   == 13

int lf = 10;  // ASCII linefeed == 10

void setup() {

  size(512, 512);

  noStroke();

  colorMode(RGB);

  fill(0.4);

  port = new Serial(this, portname, 9600);

}

void draw() {

}

void drawLine (int val) {

  background(0);

  for(int i=0;i<512;i++) {

    fill(val, 255-val, val/4);

    delay(1);

    ellipse(i, 100, 50, 50); 

  }

  for(int j=0; j<256; j++) {

    fill(val/4, 255-val, val);

    delay(1);

    ellipse(j, 300, 50, 50); 

  }

  for(int k=0; k<158; k++) {

    fill(255-val, val/2, val);

    delay(1);

    ellipse(k, 400, 50, 50); 

  }

}

// called whenever serial data arrives

void serialEvent(Serial p) {

  int c = port.read();

  if (c != lf && c != cr) {

    buf += char(c);

  }

  if (c == lf) {

    int val = int(buf);

    println("val="+val); 

    if(val > 100) {

      drawLine(val);

    }

    buf = "";

  }

}