Arduino Pong

//1D Pong
//created by Andrew Schmidt (aschmidt20)
//June 21, 2013

int ledPins[] = {2,3,4,5,6,7,8,9};
int button1Pin = 10;
int button2Pin = 11;
int button1State, button2State;
String gameInstance = "start";
int player1Score, player2Score = 0;
int delayTime;


void setup()
{
  int index;
  for(index = 0; index <= 7; index++)
  {
    pinMode(ledPins[index], OUTPUT);
  }
  pinMode(button1Pin, INPUT);
  pinMode(button2Pin, INPUT);
  delayTime = 100;
}

void loop()
{                                 // Different points of the game as String variables
  if (gameInstance == "start")
  {
    leftRight();
  }
  else if (gameInstance == "player 1 return")
  {
    delayTime = delayTime - 5; // increases speed of "ball"
    rightLeft();
  }
  else if (gameInstance == "player 2 return")
  {
    delayTime = delayTime - 5;
    leftRight();
  }
  else if (gameInstance == "player 1 point")
  {
    player1Score++;
    delayTime = 100; // resets delay after every point
    showScore();
  }
  else if (gameInstance == "player 2 point")
  {
    player2Score++;
    delayTime = 100;
    showScore();
  }

}

void leftRight() // LEDs light up from Left to Right then check if the button is pressed
{
  int index;

  for(index = 0; index <= 6; index++)
  {
    digitalWrite(ledPins[index], HIGH);
    delay(delayTime);
    digitalWrite(ledPins[index], LOW);
  }
  digitalWrite(ledPins[7], HIGH);

  button1State = digitalRead(button1Pin);

  if (button1State == LOW)           // sets gameInstance for when it goes through the main Loop
  {
    gameInstance = "player 1 return";
  }
  else
  {
    gameInstance = "player 2 point";
  }
  digitalWrite(ledPins[7], LOW);
}

void rightLeft()  // LEDs light up from Right to Left then check if the button is pressed
{
  int index;

  for(index = 7; index >=1; index--)
  {
    digitalWrite(ledPins[index], HIGH);
    delay(delayTime);
    digitalWrite(ledPins[index], LOW);
  }
  digitalWrite(ledPins[0], HIGH);

  button2State = digitalRead(button2Pin);

  if (button2State == LOW)
  {
    gameInstance = "player 2 return";
  }
  else
  {
    gameInstance = "player 1 point";
  }
  digitalWrite(ledPins[0], LOW);
}

void showScore()
{
// Show player 1 score
  if (player1Score == 1)
  {
    digitalWrite(ledPins[7], HIGH);
  }
  else if (player1Score == 2)
  {
    digitalWrite(ledPins[7], HIGH);
    digitalWrite(ledPins[6], HIGH);
  }
  else if (player1Score == 3)
  {
    digitalWrite(ledPins[7], HIGH);
    digitalWrite(ledPins[6], HIGH);
    digitalWrite(ledPins[5], HIGH);
  }
  else if (player1Score == 4)
  {
    digitalWrite(ledPins[7], HIGH);
    digitalWrite(ledPins[6], HIGH);
    digitalWrite(ledPins[5], HIGH);
    digitalWrite(ledPins[4], HIGH);
  }


 // Show player 2 score
  if (player2Score == 1)
  {
    digitalWrite(ledPins[0], HIGH);
  }
  else if (player2Score == 2)
  {
    digitalWrite(ledPins[1], HIGH);
    digitalWrite(ledPins[0], HIGH);
  }
  else if (player2Score == 3)
  {
    digitalWrite(ledPins[2], HIGH);
    digitalWrite(ledPins[1], HIGH);
    digitalWrite(ledPins[0], HIGH);
  }
  else if (player2Score == 4)
  {
    digitalWrite(ledPins[3], HIGH);
    digitalWrite(ledPins[2], HIGH);
    digitalWrite(ledPins[1], HIGH);
    digitalWrite(ledPins[0], HIGH);
  }

  delay(2000);
  ledsOff();

  if (player1Score == 4)    // If the game is over, marquee in direction of winner
  {
    marqueeRight();
  }
  else if (player2Score == 4)
  {
    marqueeLeft();
  }

  gameInstance = "start";
}

void ledsOff()  // Turns off all LEDs
{
  int index;

  for(index = 0; index <= 7; index++)
  {
    digitalWrite(ledPins[index], LOW);
  }
}

void marqueeRight()  // Marquee code from Inventor's Kit examples, modified for length and direction
{
  int index;
  int indez;
  int delayTime = 100; // milliseconds to pause between LEDs
                       // Make this smaller for faster switching

  // Step through the first four LEDs
  // (We'll light up one in the lower 4 and one in the upper 4)
  for(indez = 0; indez<= 5; indez++)
  {
    for(index = 0; index <= 3; index++) // Step from 0 to 3
    {
      digitalWrite(ledPins[index], HIGH);    // Turn a LED on
      digitalWrite(ledPins[index+4], HIGH);  // Skip four, and turn that LED on
      delay(delayTime);                      // Pause to slow down the sequence
      digitalWrite(ledPins[index], LOW);     // Turn the LED off
      digitalWrite(ledPins[index+4], LOW);   // Skip four, and turn that LED off
    }
  }

  delay(2500);
  gameRestart();
}

void marqueeLeft()
{
  int index;
  int indez;
  int delayTime = 100; // milliseconds to pause between LEDs
                       // Make this smaller for faster switching

  // Step through the first four LEDs
  // (We'll light up one in the lower 4 and one in the upper 4)
  for(indez = 0; indez<= 5; indez++)
  {
    for(index = 3; index >= 0; index--) // Step from 0 to 3
    {
      digitalWrite(ledPins[index], HIGH);    // Turn a LED on
      digitalWrite(ledPins[index+4], HIGH);  // Skip four, and turn that LED on
      delay(delayTime);                      // Pause to slow down the sequence
      digitalWrite(ledPins[index], LOW);     // Turn the LED off
      digitalWrite(ledPins[index+4], LOW);   // Skip four, and turn that LED off
    }
  }

  delay(2500);
  gameRestart();
}

void gameRestart()  // Restarts game, variables back to original
{
  player1Score = 0;
  player2Score = 0;
  gameInstance = "start";
  delayTime = 100;
}