/// <summary>
        /// Allows the game to run logic such as updating the world,
        /// checking for collisions, gathering input, and playing audio.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Update(GameTime gameTime)
        {
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
            {
                this.Exit();
            }

            // These statements check to see if there are any invaders remaining to shoot
            bool IsInvaderRemaining = false;

            for (int Count = 0; Count < 11; Count++)
            {
                if (Invaders[Count] != null)
                {
                    IsInvaderRemaining = true;
                    break;
                }
            }

            // If there are no invaders then move to end game state
            if (!IsInvaderRemaining)
            {
                this.Exit();
            }

            if (MissileFired != null)
            {
                MissileFired.Move();
            }

            if (Keyboard.GetState().IsKeyDown(Keys.Space))
            {
                MissileFired = new Missile(RocketXPos, 650);
            }

            // TODO: Add your update logic here
            if (Keyboard.GetState().IsKeyDown(Keys.Left))
            {
                RocketXPos = RocketXPos - 4;
            }

            if (Keyboard.GetState().IsKeyDown(Keys.Right))
            {
                RocketXPos = RocketXPos + 4;
            }

            if (RocketXPos < 100)
            {
                RocketXPos = 100;
            }

            if (RocketXPos > 924)
            {
                RocketXPos = 924;
            }


            Ticks = Ticks + gameTime.ElapsedGameTime.TotalMilliseconds;

            if (Ticks > 500)
            {
                for (int Count = 0; Count < 11; Count++)
                {
                    if (Invaders[Count] != null)
                    {
                        Invaders[Count].MoveHorizontal(AlienSpeed * AlienDirection);
                    }
                }

                Invader LeftMostInvader  = null;
                Invader RightMostInvader = null;

                for (int Count = 0; Count < 11; Count++)
                {
                    if (Invaders[Count] != null)
                    {
                        LeftMostInvader = Invaders[Count];
                        break;
                    }
                }

                for (int Count = 10; Count > 0; Count--)
                {
                    if (Invaders[Count] != null)
                    {
                        RightMostInvader = Invaders[Count];
                        break;
                    }
                }

                if (LeftMostInvader.GetXPos() < 96)
                {
                    AlienDirection = +1;

                    int XPos = 96;
                    for (int Count = 0; Count < 11; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(4);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }
                }

                if (RightMostInvader.GetXPos() > 924)
                {
                    AlienDirection = -1;

                    int XPos = 924 - InvaderImg.Width * 10;
                    for (int Count = 0; Count < 11; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(4);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }
                }

                Ticks = 0;
            }

            if (MissileFired != null)
            {
                Rectangle rectMissile = new Rectangle((int)MissileFired.GetPosition().X, (int)MissileFired.GetPosition().Y, MissileImg.Width, MissileImg.Height);

                for (int Count = 0; Count < 11; Count++)
                {
                    if (Invaders[Count] != null)
                    {
                        Rectangle rectInvader = new Rectangle(Invaders[Count].GetXPos(), Invaders[Count].GetYPos(), InvaderImg.Width, InvaderImg.Height);

                        if (rectMissile.Intersects(rectInvader))
                        {
                            Invaders[Count] = null;
                            MissileFired    = null;

                            break;
                        }
                    }
                }
            }

            base.Update(gameTime);
        }
        //Update method for Gameplay screen
        // TODO: Add your update logic here
        public void UpdatePlaying(GameTime currentTime)
        {
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
            {
                GameState = 3;
                return;
            }
            //Implemented to make testing easier
            //easily switch through different game states
            if (Keyboard.GetState().IsKeyDown(Keys.F1))
            {
                StarwarsSoundInstance.Stop();
                GameState = 1;
                return;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.F2))
            {
                GameState = 2;
                return;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.F3))
            {
                GameState = 3;
                return;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.F4))
            {
                GameState = 4;
                return;
            }
            if (Keyboard.GetState().IsKeyDown(Keys.F5))
            {
                GameState = 5;
                return;
            }
            //Allows switching between weapons (Also allows easier testing cos of faster gameplay)
            if (Keyboard.GetState().IsKeyDown(Keys.D1))
            {
                WeaponsCount = 1;
                Weapon1SoundInstance.Play();
            }
            if (Keyboard.GetState().IsKeyDown(Keys.D2))
            {
                WeaponsCount = 2;
                Weapon2SoundInstance.Play();
            }

            // These statements check to see if there are any invaders remaining to shoot
             bool IsBossInvaderRemaining = false;
                if (BossAlien != null)
                {
                    IsBossInvaderRemaining = true;      //If statement checks if the Boss alien is still remaining
                }

            bool IsInvaderRemaining = false;
            for (int Count = 0; Count < 11; Count++)
            {
                //First Array
                if (Invaders[Count] != null)        //If statement is null that means there are no Aliens left for that particular Array
                {
                    IsInvaderRemaining = true;
                    break;
                }
                //Second Array
                if (InvadersOne[Count] != null)
                {
                    IsInvaderRemaining = true;
                    break;
                }
                //Third Array
                if (InvadersTwo[Count] != null)
                {
                    IsInvaderRemaining = true;
                    break;
                }
                //Fourth Array
                if (InvadersThree[Count] != null)
                {
                    IsInvaderRemaining = true;
                    break;
                }
                //Fifth Array
                if (InvadersFour[Count] != null)
                {
                    IsInvaderRemaining = true;
                    break;
                }
            }

            // If there are no invaders then move to end game state (Gamestate 3)
            if (!IsInvaderRemaining & !IsBossInvaderRemaining)
            {
                GameState = 3;
                return;
            }

            //Player Missile
            if (BossAlien != null & (WeaponsCount == 1 || WeaponsCount ==2))    //Checks if Boss Alien is destroyed and what weapon count it is on
            {                                                                   //This allows weapons power up if Boss is destroyed and switching of weapons
                if (MissileFired != null)
                {
                    MissileFired.Move();
                }

                if (Keyboard.GetState().IsKeyDown(Keys.Space))                  //Fires missile from the location of rocket, if Space bar is pressed
                {
                    MissileFired = new Missile(RocketXPos, 650);
                    ShootSoundInstance.Play();                                  //Sound is also played
                }
            }
            //Switch weapons //Used for testing to save time
            if (WeaponsCount == 2)
            {
                if (MissileFired != null)
                {
                    MissileFired.Move2();
                }
                if (Keyboard.GetState().IsKeyDown(Keys.Space))
                {
                    MissileFired = new Missile(RocketXPos, 650);
                    Shoot3SoundInstance.Play();
                }
            }
            //If Boss alien has been destroyed use second missile (Upgrade weapons/ Power up)
            if (BossAlien == null)
            {
                if (MissileFired != null)
                {
                    MissileFired.Move3();
                }
                if (Keyboard.GetState().IsKeyDown(Keys.Space))
                {
                    MissileFired = new Missile(RocketXPos, 650);
                    if (WeaponsCount == 1)
                    {
                        Shoot2SoundInstance.Play();
                    }
                }
            }
            //Alien Missile
            if (AlienMissileFired != null)  //If Alien missile is not equal to Null then alien missile starts moving
            {
                AlienMissileFired.Move();
            }
            if (AlienMissileFired2 != null)
            {
                AlienMissileFired2.Move();
            }
            if (AlienMissileFired3 != null)
            {
                AlienMissileFired3.Move();
            }
            if (AlienMissileFired4 != null)
            {
                AlienMissileFired4.Move();
            }
            if (BossMissileFired != null)
            {
                BossMissileFired.Move();
            }
            Timer = Timer + currentTime.ElapsedGameTime.Milliseconds;   //Timer to control the automation of alien/Boss shooting
            Timer2 = Timer2 + currentTime.ElapsedGameTime.Milliseconds;
            Timer3 = Timer3 + currentTime.ElapsedGameTime.Milliseconds;
            Timer4 = Timer4 + currentTime.ElapsedGameTime.Milliseconds;
            BossTimer = BossTimer + currentTime.ElapsedGameTime.Milliseconds;

            //First Array
            if (Timer > 2865)   //The timer values can be adjusted at each array to change the frequency of the automatic shooting
            {
                for (int Count = 0; Count < 11; Count++)                                                               //Checks the amount of aliens
                {
                    if (Invaders[Count] != null)                                                                        //If available then fires from alien at the player
                    {
                        AlienMissileFired = new AlienMissile(Invaders[Count].GetXPos(), Invaders[Count].GetYPos());     //Fires from the X and Y coordinates of existing aliens
                        AlienShootSoundInstance.Play();
                        Timer = 0;                                                                                      //Timer is reset back to 0 for continious shooting
                    }
                    }
              }
            //Second Array
            if (Timer2 > 4234)
            {
                for (int Count = 0; Count < 11; Count++)
                {
                    if (InvadersTwo[Count] != null)
                    {
                        AlienMissileFired2 = new AlienMissile(InvadersTwo[Count].GetXPos(), InvadersTwo[Count].GetYPos());
                        AlienShootSoundInstance.Play();
                        Timer2 = 0;
                    }
                }
            }
            //Third Array
            if (Timer3 > 6403)
            {
                for (int Count = 0; Count < 11; Count++)
                {
                    if (InvadersThree[Count] != null)
                    {
                        AlienMissileFired3 = new AlienMissile(InvadersThree[Count].GetXPos(), InvadersThree[Count].GetYPos());
                        AlienShootSoundInstance.Play();
                        Timer3 = 0;
                    }
                }
            }
            //Fourth Array
            if (Timer4 > 8000)
            {
                for (int Count = 0; Count < 11; Count++)
                {
                    if (InvadersFour[Count] != null)
                    {
                        AlienMissileFired4 = new AlienMissile(InvadersFour[Count].GetXPos(), InvadersFour[Count].GetYPos());
                        AlienShootSoundInstance.Play();
                        Timer4 = 0;
                    }
                }
            }
            //Boss Missile
            if (BossTimer > 7800)
            {
                    if (BossAlien != null)
                    {
                        BossMissileFired = new AlienMissile(BossAlien.GetXPos(), BossAlien.GetYPos());
                        BossShootSoundInstance.Play();
                        BossTimer = 0;
                    }
            }
             //Controls movement of the Aircraft and sound effects
            if (Keyboard.GetState().IsKeyDown(Keys.Left))
            {
                if (BossAlien != null)
                {
                RocketXPos = RocketXPos - 4;      //Changing this will affect the speed of the rocket
                JetSoundInstance.Play();
                 }
                if (BossLife == 2)
                {
                    RocketXPos = RocketXPos - 5;     //Upgrade if boss is hit (Move faster)
                    JetSoundInstance.Play();
                }
                if (BossLife == 1)
                {
                    RocketXPos = RocketXPos - 6;      //Upgrade if boss is hit (Move faster)
                    JetSoundInstance.Play();
                }
                if (BossAlien == null & BossLife == 0)
                {
                    RocketXPos = RocketXPos - 8;      //Upgrade if boss is destroyed (Move faster)
                    JetSoundInstance.Play();
                }
            }

            if (Keyboard.GetState().IsKeyDown(Keys.Right))
            {
                if (BossAlien != null)
                {
                    RocketXPos = RocketXPos + 4;      //Changing this will affect the speed of the rocket
                    JetSoundInstance.Play();
                }
                if (BossLife == 2)
                {
                    RocketXPos = RocketXPos + 5;      //Upgrade if boss is hit (Move faster)
                    JetSoundInstance.Play();
                }
                if (BossLife == 1)
                {
                    RocketXPos = RocketXPos + 6;      //Upgrade if boss is hit (Move faster)
                    JetSoundInstance.Play();
                }
                if (BossAlien == null & BossLife == 0)
                {
                    RocketXPos = RocketXPos + 8;      //Upgrade if boss is destroyed (Move faster)
                    JetSoundInstance.Play();
                }
            }

            if (RocketXPos < 100)       //Limits the Rockets movement to prevent it from going off the screen
            {
                RocketXPos = 100;
            }

            if (RocketXPos > 924)
            {
                RocketXPos = 924;
            }

            //Controls movement of Alien
            Ticks = Ticks + currentTime.ElapsedGameTime.TotalMilliseconds;  //Calculates the ingame time for the movement of aliens

            if (Ticks > 500)    //if the timer is more than 500 then moves the alien horizontal
            {
                for (int Count = 0; Count < 11; Count++)
                {
                    //First Array
                    if (Invaders[Count] != null)
                    {
                        Invaders[Count].MoveHorizontal(AlienSpeed * AlienDirection);
                    }
                    //second array
                    if (InvadersOne[Count] != null)
                    {
                        InvadersOne[Count].MoveHorizontal(AlienSpeed * AlienDirection);
                    }
                    //Third array
                    if (InvadersTwo[Count] != null)
                    {
                        InvadersTwo[Count].MoveHorizontal(AlienSpeed * AlienDirection);
                    }
                    //Fourth array
                    if (InvadersThree[Count] != null)
                    {
                        InvadersThree[Count].MoveHorizontal(AlienSpeed * AlienDirection);
                    }
                    //Fifth array
                    if (InvadersFour[Count] != null)
                    {
                        InvadersFour[Count].MoveHorizontal(AlienSpeed * AlienDirection);
                    }
                }
                //Boss Alien movement
                if (Ticks > 500)
                {
                    if (BossAlien != null)
                    {
                        BossAlien.MoveHorizontal(BossAlienSpeed * BossAlienDirection);
                    }
                    if (BossLife == 1)
                    {
                        BossAlienSpeed = 105;
                        BossAlien.MoveHorizontal(BossAlienSpeed * BossAlienDirection);
                    }
                }
                Invader LeftMostInvader = null; //Aliens set to null
                Invader RightMostInvader = null;

                for (int Count = 0; Count < 11; Count++)
                {
                    //First Array
                    if (Invaders[Count] != null)
                    {
                        LeftMostInvader = Invaders[Count];
                        break;
                    }
                    //second array
                    if (InvadersOne[Count] != null)
                    {
                        LeftMostInvader = InvadersOne[Count];
                        break;
                    }
                    //Third array
                    if (InvadersTwo[Count] != null)
                    {
                        LeftMostInvader = InvadersTwo[Count];
                        break;
                    }
                    //Fourth array
                    if (InvadersThree[Count] != null)
                    {
                        LeftMostInvader = InvadersThree[Count];
                        break;
                    }
                    //Fifth array
                    if (InvadersFour[Count] != null)
                    {
                        LeftMostInvader = InvadersFour[Count];
                        break;
                    }
                }

                for (int Count = 10; Count > 0; Count--)
                {
                    //First Array
                    if (Invaders[Count] != null)
                    {
                        RightMostInvader = Invaders[Count];
                        break;
                    }
                    //second array
                    if (InvadersOne[Count] != null)
                    {
                        RightMostInvader = InvadersOne[Count];
                        break;
                    }
                    //Third array
                    if (InvadersTwo[Count] != null)
                    {
                        RightMostInvader = InvadersTwo[Count];
                        break;
                    }
                    //Fourth array
                    if (InvadersThree[Count] != null)
                    {
                        RightMostInvader = InvadersThree[Count];
                        break;
                    }
                    //Fifth array
                    if (InvadersFour[Count] != null)
                    {
                        RightMostInvader = InvadersFour[Count];
                        break;
                    }
                }

                //Controls alien speed/difficulty
                if (LeftMostInvader != null)                     //Checks if aliens is available
                {
                    if (LeftMostInvader.GetYPos() > 200)         //Increases alien speed after to goes pass a certain Y coordinate
                    {
                        AlienSpeed = 50;
                    }
                }
                if (RightMostInvader != null)
                {
                    if (RightMostInvader.GetYPos() > 200)
                    {
                        AlienSpeed = 50;
                    }
                }
                  if (LeftMostInvader != null)
                {
                if (LeftMostInvader.GetYPos() > 300)
                {
                    AlienSpeed = 60;
                }
                }
                  if (RightMostInvader != null)
                  {
                      if (RightMostInvader.GetYPos() > 300)
                      {
                          AlienSpeed = 60;
                      }
                  }

                //Game Over when aliens reach the bottom, navigates to Gameover screen
                 if (LeftMostInvader != null)
                  {
                if (LeftMostInvader.GetYPos() > 550)
                {
                    GameState = 4;          //Goes to gameover screen
                    return;
                }
                }
                      if (RightMostInvader != null)
                  {
                if (RightMostInvader.GetYPos() > 550)
                {
                    GameState = 4;
                    return;
                }
                  }

                //Checks Boss alien direction
                if (BossAlien != null)
                    {
                     if (BossAlien.GetXPos() < 96)   //Limits the aliens direction to prevent it from going off the screen
                     {
                    BossAlienDirection = +1;
                    int BossXPos = 96;
                    if (BossAlien != null)
                    {
                        BossAlien.SetXPos(BossXPos);
                    }
                    BossXPos = BossXPos + BossInvaderImg.Width;
                }
                    }
                  if (BossAlien != null)
                    {
                if (BossAlien.GetXPos() > 924)
                {
                    BossAlienDirection = -1;
                    int BossXPos = 924 - BossInvaderImg.Width * 10;
                    if (BossAlien != null)
                    {
                        BossAlien.SetXPos(BossXPos);
                    }
                    BossXPos = BossXPos + BossInvaderImg.Width;
                       }
                    }
                //Checks  alien direction
                if (LeftMostInvader != null)
                  {
                if (LeftMostInvader.GetXPos() < 96)
                {
                    AlienDirection = +1;
                    int XPos = 96;
                    for (int Count = 0; Count < 11; Count++)    //Checks the array for the position of the aliens before moving them vertically once they reached the side
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(20);
                            Invaders[Count].SetXPos(XPos);
                        }
                        //Second Array
                        if (InvadersOne[Count] != null)
                        {
                            InvadersOne[Count].MoveVertical(20);
                            InvadersOne[Count].SetXPos(XPos);
                        }
                        //Third Array
                        if (InvadersTwo[Count] != null)
                        {
                            InvadersTwo[Count].MoveVertical(20);
                            InvadersTwo[Count].SetXPos(XPos);
                        }
                        //Fourth Array
                        if (InvadersThree[Count] != null)
                        {
                            InvadersThree[Count].MoveVertical(20);
                            InvadersThree[Count].SetXPos(XPos);
                        }
                        //Fifth Array
                        if (InvadersFour[Count] != null)
                        {
                            InvadersFour[Count].MoveVertical(20);
                            InvadersFour[Count].SetXPos(XPos);
                        }
                        XPos = XPos + InvaderImg.Width;
                    }
                }
                  }
                if (RightMostInvader != null)       //Does the same check with rightmost alien
                {
                    if (RightMostInvader.GetXPos() > 924)
                    {
                        AlienDirection = -1;
                        int XPos = 924 - InvaderImg.Width * 10;
                        for (int Count = 0; Count < 11; Count++)
                        {
                            if (Invaders[Count] != null)
                            {
                                Invaders[Count].MoveVertical(20);
                                Invaders[Count].SetXPos(XPos);
                            }
                            //Second Array
                            if (InvadersOne[Count] != null)
                            {
                                InvadersOne[Count].MoveVertical(20);
                                InvadersOne[Count].SetXPos(XPos);
                            }
                            //Third Array
                            if (InvadersTwo[Count] != null)
                            {
                                InvadersTwo[Count].MoveVertical(20);
                                InvadersTwo[Count].SetXPos(XPos);
                            }
                            //Fourth Array
                            if (InvadersThree[Count] != null)
                            {
                                InvadersThree[Count].MoveVertical(20);
                                InvadersThree[Count].SetXPos(XPos);
                            }
                            //Fifth Array
                            if (InvadersFour[Count] != null)
                            {
                                InvadersFour[Count].MoveVertical(20);
                                InvadersFour[Count].SetXPos(XPos);
                            }
                            XPos = XPos + InvaderImg.Width;
                        }
                    }
                }

                Ticks = 0;
            }

            //Checks whether alien missile intersects with Player
            //If intesects then Lose life or Game Over
            //First array
                       if (AlienMissileFired != null)
                   {
                       Rectangle rectAlienMissile = new Rectangle((int)AlienMissileFired.GetPosition().X, (int)AlienMissileFired.GetPosition().Y, AlienMissileImg.Width, AlienMissileImg.Height);
                Rectangle rectRocket = new Rectangle(RocketXPos, 700, RocketLauncherImg.Width, RocketLauncherImg.Height);

                        if (rectAlienMissile.Intersects(rectRocket))
                        {
                            if (AmountofLives == 0)
                            {
                            AlienMissileFired = null;
                            GameState = 4;
                            PlayerKilledSoundInstance.Play();
                            }
                            AmountofLives = AmountofLives - 1;      //Player life is subtract from total life
                            AlienMissileFired = null;               //When this reaches 0 then it switches over to Game Over screen
                            PlayerKilledSoundInstance.Play();
                        }
                    }
                       //Second array
                       if (AlienMissileFired2 != null)
                       {
                           Rectangle rectAlienMissile2 = new Rectangle((int)AlienMissileFired2.GetPosition().X, (int)AlienMissileFired2.GetPosition().Y, AlienMissileImg2.Width, AlienMissileImg2.Height);
                           Rectangle rectRocket = new Rectangle(RocketXPos, 700, RocketLauncherImg.Width, RocketLauncherImg.Height);

                           if (rectAlienMissile2.Intersects(rectRocket))
                           {
                               if (AmountofLives == 0)
                               {
                                   AlienMissileFired2 = null;
                                   GameState = 4;
                                   PlayerKilledSoundInstance.Play();
                               }
                               AmountofLives = AmountofLives - 1;
                               AlienMissileFired2 = null;
                               PlayerKilledSoundInstance.Play();
                           }
                       }
                       //Third array
                       if (AlienMissileFired3 != null)
                       {
                           Rectangle rectAlienMissile3 = new Rectangle((int)AlienMissileFired3.GetPosition().X, (int)AlienMissileFired3.GetPosition().Y, AlienMissileImg2.Width, AlienMissileImg2.Height);
                           Rectangle rectRocket = new Rectangle(RocketXPos, 700, RocketLauncherImg.Width, RocketLauncherImg.Height);

                           if (rectAlienMissile3.Intersects(rectRocket))
                           {
                               if (AmountofLives == 0)
                               {
                                   AlienMissileFired3 = null;
                                   GameState = 4;
                                   PlayerKilledSoundInstance.Play();
                               }
                               AmountofLives = AmountofLives - 1;
                               AlienMissileFired3 = null;
                               PlayerKilledSoundInstance.Play();
                           }
                       }
                       //Fourth array
                       if (AlienMissileFired4 != null)
                       {
                           Rectangle rectAlienMissile4 = new Rectangle((int)AlienMissileFired4.GetPosition().X, (int)AlienMissileFired4.GetPosition().Y, AlienMissileImg2.Width, AlienMissileImg2.Height);
                           Rectangle rectRocket = new Rectangle(RocketXPos, 700, RocketLauncherImg.Width, RocketLauncherImg.Height);

                           if (rectAlienMissile4.Intersects(rectRocket))
                           {
                               if (AmountofLives == 0)
                               {
                                   AlienMissileFired4 = null;
                                   GameState = 4;
                                   PlayerKilledSoundInstance.Play();
                               }
                               AmountofLives = AmountofLives - 1;
                               AlienMissileFired4 = null;
                               PlayerKilledSoundInstance.Play();
                           }
                       }
            //Boss Missile
                       if (BossMissileFired != null)
                       {
                           Rectangle rectBossMissile = new Rectangle((int)BossMissileFired.GetPosition().X, (int)BossMissileFired.GetPosition().Y, BossMissileImg.Width, BossMissileImg.Height);
                           Rectangle rectRocket = new Rectangle(RocketXPos, 700, RocketLauncherImg.Width, RocketLauncherImg.Height);

                           if (rectBossMissile.Intersects(rectRocket))
                           {
                               if (AmountofLives == 0)
                               {
                                   BossMissileFired = null;
                                   GameState = 4;
                                   PlayerKilledSoundInstance.Play();
                               }
                               AmountofLives = AmountofLives - 1;
                               BossMissileFired = null;
                               PlayerKilledSoundInstance.Play();
                           }
                       }

            //Controls missle being fired
            //Checks whether missile intersects with Boss
                       if (MissileFired != null)
                       {
                           Rectangle rectMissile = new Rectangle((int)MissileFired.GetPosition().X, (int)MissileFired.GetPosition().Y, MissileImg.Width, MissileImg.Height);
                           //Creates a rectangle in order to compare whether the missile intercepts with alien
                           if (BossAlien != null)
                           {
                               Rectangle rectBossInvader = new Rectangle(BossAlien.GetXPos(), BossAlien.GetYPos(), BossInvaderImg.Width, BossInvaderImg.Height);

                               if (rectMissile.Intersects(rectBossInvader))
                               {
                                   BossLife = BossLife - 1;
                                   MissileFired = null;
                                   PlayerScore = PlayerScore + 1000;    //Killing boss gives more score
                                   ExplosionSoundInstance.Play();

                                   if (BossLife == 0)
                                   {
                                       BossAlien = null;
                                       WeaponsCount = 1;    //Also gives a power up (Weapon upgrade)
                                       PlayerScore = PlayerScore + 1000;
                                       BosskilledSoundInstance.Play();
                                       ExplosionSoundInstance.Play();
                                   }
                               }
                           }
                       }

            // Checks whether the missle intersects with Alien
            if (MissileFired != null)
            {
                Rectangle rectMissile = new Rectangle((int)MissileFired.GetPosition().X, (int)MissileFired.GetPosition().Y, MissileImg.Width, MissileImg.Height);

                for (int Count = 0; Count < 11; Count++)  //Rectangle is created to check whether both object intesect each other
                {
                    if (Invaders[Count] != null)         //If it does then the alien is declared as null (destroyed)
                    {
                        if (BossAlien == null)
                        {
                            rectMissile = new Rectangle((int)MissileFired.GetPosition().X, (int)MissileFired.GetPosition().Y, MissileImg2.Width, MissileImg2.Height);
                        }
                        Rectangle rectInvader = new Rectangle(Invaders[Count].GetXPos(), Invaders[Count].GetYPos(), InvaderImg.Width, InvaderImg.Height);

                        if (rectMissile.Intersects(rectInvader))
                        {
                            Invaders[Count] = null;
                            MissileFired = null;

                            PlayerScore = PlayerScore + 150;

                            ExplosionSoundInstance.Play();
                            InvaderkilledSoundInstance.Play();

                            break;
                        }
                    }
                    //Second Array
                    if (InvadersOne[Count] != null)
                    {
                        if (BossAlien == null)
                        {
                            rectMissile = new Rectangle((int)MissileFired.GetPosition().X, (int)MissileFired.GetPosition().Y, MissileImg2.Width, MissileImg2.Height);
                        }
                        Rectangle rectInvader = new Rectangle(InvadersOne[Count].GetXPos(), InvadersOne[Count].GetYPos(), InvaderImg.Width, InvaderImg.Height);

                        if (rectMissile.Intersects(rectInvader))
                        {

                            InvadersOne[Count] = null;
                            MissileFired = null;

                            PlayerScore = PlayerScore + 100;

                            ExplosionSoundInstance.Play();
                            InvaderkilledSoundInstance.Play();
                            break;
                        }
                    }
                    //Third Array
                    if (InvadersTwo[Count] != null)
                    {
                        if (BossAlien == null)
                        {
                            rectMissile = new Rectangle((int)MissileFired.GetPosition().X, (int)MissileFired.GetPosition().Y, MissileImg2.Width, MissileImg2.Height);
                        }
                        Rectangle rectInvader = new Rectangle(InvadersTwo[Count].GetXPos(), InvadersTwo[Count].GetYPos(), InvaderImg.Width, InvaderImg.Height);

                        if (rectMissile.Intersects(rectInvader))
                        {
                            InvadersTwo[Count] = null;
                            MissileFired = null;

                            PlayerScore = PlayerScore + 50;

                            ExplosionSoundInstance.Play();
                            InvaderkilledSoundInstance.Play();
                            break;
                        }
                    }
                    //Fourth Array
                    if (InvadersThree[Count] != null)
                    {
                        if (BossAlien == null)
                        {
                            rectMissile = new Rectangle((int)MissileFired.GetPosition().X, (int)MissileFired.GetPosition().Y, MissileImg2.Width, MissileImg2.Height);
                        }
                        Rectangle rectInvader = new Rectangle(InvadersThree[Count].GetXPos(), InvadersThree[Count].GetYPos(), InvaderImg.Width, InvaderImg.Height);

                        if (rectMissile.Intersects(rectInvader))
                        {
                            InvadersThree[Count] = null;
                            MissileFired = null;

                            PlayerScore = PlayerScore + 25;

                            ExplosionSoundInstance.Play();
                            InvaderkilledSoundInstance.Play();
                            break;
                        }
                    }
                    //Fifth Array
                    if (InvadersFour[Count] != null)
                    {
                        if (BossAlien == null)
                        {
                            rectMissile = new Rectangle((int)MissileFired.GetPosition().X, (int)MissileFired.GetPosition().Y, MissileImg2.Width, MissileImg2.Height);
                        }
                        Rectangle rectInvader = new Rectangle(InvadersFour[Count].GetXPos(), InvadersFour[Count].GetYPos(), InvaderImg.Width, InvaderImg.Height);

                        if (rectMissile.Intersects(rectInvader))
                        {
                            InvadersFour[Count] = null;
                            MissileFired = null;

                            PlayerScore = PlayerScore + 25;

                            ExplosionSoundInstance.Play();
                            InvaderkilledSoundInstance.Play();
                            break;
                        }
                    }
                }
            }
        }
Exemple #3
0
        // Main Update
        public void UpdatePlaying(GameTime currentTime)
        {
            //stop the theme song during the gameplay
            ThemeSoundInstance.Stop();

            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
            {
                this.Exit();
            }

            // These statements check to see if there are any invaders remaining to shoot
            bool IsInvaderRemaining = false;

            for (int Count = 0; Count < 55; Count++)
            {
                if (Invaders[Count] != null)
                {
                    IsInvaderRemaining = true;
                    break;
                }
            }

            // If there are no invaders then move to end game state
            if (!IsInvaderRemaining)
            {
                GameState = 4;

                return;
            }
            //move missle if active
            if (MissileFired != null)
            {
                MissileFired.Move();
            }

            //if space is pressed, initiate missile
            if (Keyboard.GetState().IsKeyDown(Keys.Space))
            {
                //i found it irritating that pressing space would remove the existing missile
                //now, a missile will only shoot if there is no existing missile
                if (MissileFired == null)
                {
                    //at location of rocket
                    MissileFired = new Missile(RocketXPos, 650);

                    //play shooting sound
                    ShootSoundInstance.Play();
                }
            }

            //with the added code for pressing space,
            //we need to kill the missile if it goes off the screen.
            //otherwise if the missile misses an invader, it will continue forever you you will be unable to shoot another
            //if there is a missile

            if (MissileFired != null)
            {
                //above 1 Y co-ordinate
                if (MissileFired.GetPosition().Y < 1)
                {
                    //kill
                    MissileFired = null;
                }
            }

            // Move the rocket left and right
            if (Keyboard.GetState().IsKeyDown(Keys.Left))
            {
                RocketXPos = RocketXPos - 4;
            }

            if (Keyboard.GetState().IsKeyDown(Keys.Right))
            {
                RocketXPos = RocketXPos + 4;
            }

            //Keep the rocket on the screen
            if (RocketXPos < 100)
            {
                RocketXPos = 100;
            }

            if (RocketXPos > 924)
            {
                RocketXPos = 924;
            }


            //Moving The Invaders
            Ticks = Ticks + currentTime.ElapsedGameTime.TotalMilliseconds;

            //variable for changing speed
            int speedInt = 500;

            //vairable for choosing invader
            int invaderChoose = 0;

            //find the first invader which isnt dead
            do
            {
                invaderChoose = invaderChoose + 1;
            }while (Invaders[invaderChoose] == null);

            //assign speed depending on y position of selected invader

            if (Invaders[invaderChoose].GetYPos() < 200)
            {
                speedInt = 500;
            }
            else if (Invaders[invaderChoose].GetYPos() > 200)
            {
                speedInt = 300;
            }
            else if (Invaders[invaderChoose].GetYPos() > 400)
            {
                speedInt = 100;
            }

            // move invaders
            if (Ticks > speedInt)
            {
                //Play sound each time they move
                InvaderSoundInstance.Play();
                //setting initial speed and direction
                for (int Count = 0; Count < 55; Count++)
                {
                    if (Invaders[Count] != null)
                    {
                        Invaders[Count].MoveHorizontal(AlienSpeed * AlienDirection);
                    }
                }

                Invader LeftMostInvader  = null;
                Invader RightMostInvader = null;


                for (int Count = 0; Count < 11; Count++)
                {
                    if (Invaders[Count] != null)
                    {
                        LeftMostInvader = Invaders[Count];
                        break;
                    }
                }

                for (int Count = 10; Count > 0; Count--)
                {
                    if (Invaders[Count] != null)
                    {
                        RightMostInvader = Invaders[Count];
                        break;
                    }
                }

                if (LeftMostInvader.GetXPos() < 96)
                {
                    AlienDirection = +1;

                    int XPos = 96;


                    for (int Count = 0; Count < 11; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }

                    XPos = 96;
                    for (int Count = 11; Count < 22; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }

                    XPos = 96;
                    for (int Count = 22; Count < 33; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }

                    XPos = 96;
                    for (int Count = 33; Count < 44; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }
                    XPos = 96;
                    for (int Count = 44; Count < 55; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }
                }


                // Keeping launcher in constraints of invaders
                if (RocketXPos < LeftMostInvader.GetXPos())
                {
                    RocketXPos = LeftMostInvader.GetXPos();
                }
                if (RocketXPos > RightMostInvader.GetXPos())
                {
                    RocketXPos = RightMostInvader.GetXPos();
                }

                // Moving Invaders left and right
                if (RightMostInvader.GetXPos() > 924)
                {
                    AlienDirection = -1;

                    int XPos = 924 - InvaderImg.Width * 11;
                    for (int Count = 0; Count < 11; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }

                    XPos = 924 - InvaderImg.Width * 11;
                    for (int Count = 11; Count < 22; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }

                    XPos = 924 - InvaderImg.Width * 11;
                    for (int Count = 22; Count < 33; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }

                    XPos = 924 - InvaderImg.Width * 11;
                    for (int Count = 33; Count < 44; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }

                    XPos = 924 - InvaderImg.Width * 11;
                    for (int Count = 44; Count < 55; Count++)
                    {
                        if (Invaders[Count] != null)
                        {
                            Invaders[Count].MoveVertical(8);
                            Invaders[Count].SetXPos(XPos);
                        }

                        XPos = XPos + InvaderImg.Width;
                    }
                }
                //Resetting millisecond count for moving invaders.
                Ticks = 0;
            }

            // UFO

            //Generate Random Value Between 1 and 500
            int ReturnValue = RandomNumber(1, 500);

            //If There is no active UFO and The Random Number Is 1, Then Set ufoalive To True
            if (ufo.ufoAlive == false && ReturnValue == 1)
            {
                ufo.ufoAlive = true;
            }

            //Count milliseconds
            ufoTime = ufoTime + currentTime.ElapsedGameTime.TotalMilliseconds;

            // If Ufoalive is true, i.e. there is an active ufo, increment  X position by 10 pixels every 100 milliseconds
            // then reset ufotime variable to zero
            if (ufo.ufoAlive == true)
            {
                if (ufoTime > 100)
                {
                    ufo.UFOxPos = ufo.UFOxPos + 10;
                    ufoTime     = 0;
                }
            }

            // if ufo position goes further than 1000 pixels, set ufoalive to false, i.e. kill the ufo. so a new one can be generated.
            if (ufo.UFOxPos > 1000)
            {
                ufo.ufoAlive = false;
                ufo.UFOxPos  = 10;
            }

            // if a missile is fired
            if (MissileFired != null)
            {
                //rectangle for missile
                Rectangle rectMissile = new Rectangle((int)MissileFired.GetPosition().X, (int)MissileFired.GetPosition().Y, MissileImg.Width, MissileImg.Height);
                //for each invader
                for (int Count = 0; Count < 55; Count++)
                {
                    if (Invaders[Count] != null)
                    {
                        Rectangle rectInvader = new Rectangle(Invaders[Count].GetXPos(), Invaders[Count].GetYPos(), InvaderImg.Width, InvaderImg.Height);
                        //Check for invader collision with the missile
                        if (rectMissile.Intersects(rectInvader))
                        {
                            //set invader and missile to null
                            Invaders[Count] = null;
                            MissileFired    = null;
                            //increase score and play collision sound
                            PlayerScore = PlayerScore + 100;
                            CollisionSoundInstance.Play();

                            break;
                        }
                    }
                }

                //checking for collison with ufo
                Rectangle rectUfo = new Rectangle(ufo.UFOxPos, 10, UFOimg.Width, UFOimg.Height);
                if (rectMissile.Intersects(rectUfo))
                {
                    //add score, jump UFO to end position, Play Collision Sound
                    PlayerScore = PlayerScore + 1000;
                    ufo.UFOxPos = 1000;

                    CollisionSoundInstance.Play();
                }
            }

            //check for collision between invader and rocker launcher
            for (int Count2 = 0; Count2 < 55; Count2++)
            {
                if (Invaders[Count2] != null)
                {
                    Rectangle rectInvader2 = new Rectangle(Invaders[Count2].GetXPos(), Invaders[Count2].GetYPos(), InvaderImg.Width, InvaderImg.Height);
                    Rectangle rectRocket   = new Rectangle(RocketXPos, 650, RocketLauncherImg.Width, RocketLauncherImg.Height);

                    if (rectInvader2.Intersects(rectRocket))
                    {
                        //if collision occurs, remove a life
                        GameLives = GameLives - 1;
                    }
                }
            }


            //Makeing the invaders fire back
            //using a new missile class which goes the opposite direction to the existing missile class
            // i felt it was easier to seperate the two classes completely than create another instance of the existing missile class and creating a reverse move.

            //if an invader isnt currently firing

            if (invaderMissile == null)
            {
                //generate random number for possibility of fire
                int RandomInvaderMissileFired = RandomNumber(1, 500);

                //if random number is equal to 1, fire a missle
                if (RandomInvaderMissileFired == 1)
                {
                    //generate second random number for choosing which invader

                    int ChooseInvader = RandomNumber(1, 55);
                    //if the invader is not dead
                    if (Invaders[ChooseInvader] != null)
                    {
                        //create new missile
                        invaderMissile = new Missile(Invaders[ChooseInvader].GetXPos(), Invaders[ChooseInvader].GetYPos());
                    }
                }
            }

            //if missile is existant
            if (invaderMissile != null)
            {
                //check for collisions
                Rectangle rectRocket         = new Rectangle(RocketXPos, 650, RocketLauncherImg.Width, RocketLauncherImg.Height);
                Rectangle rectInvaderMissile = new Rectangle((int)invaderMissile.GetPosition().X, (int)invaderMissile.GetPosition().Y, MissileImg.Width, MissileImg.Height);

                if (rectInvaderMissile.Intersects(rectRocket))
                {
                    //if collision, remove life
                    GameLives      = GameLives - 1;
                    invaderMissile = null;
                }
                //kill if no longer visible
                else if (invaderMissile.GetPosition().Y > 700)
                {
                    invaderMissile = null;
                }
                // else move the missile
                else
                {
                    invaderMissile.MoveReverse();
                }
            }

            //check remaining lives
            if (GameLives < 0)
            {
                //end game to end screen if none left
                GameState = 3;
                return;
            }
        }
        //Initialise Ingame Variables
        public void InitialiseGameVariables()
        {
            RocketXPos = 650;         //Set Rocket X value
            AlienDirection = -1;      //Set default direction
            AlienSpeed = 25;          //Sets a default speed (These can be changed in-game to increase difficulty)

            BossAlienDirection = -1;
            BossAlienSpeed = 100;

            //Declaring the Alien arrays:
            Invaders = new Invader[11];     //11 columns across
            InvadersOne = new Invader[11];
            InvadersTwo = new Invader[11];
            InvadersThree = new Invader[11];
            InvadersFour = new Invader[11];

            int XPos = 512;                 // Sets the default X coordinate for Aliens
            for (int Count = 0; Count < 11; Count++)    //Checks the count for amount of aliens
            {
                //First Array
                Invaders[Count] = new Invader();
                Invaders[Count].SetXPos(XPos);
                Invaders[Count].SetYPos(100);   //Each line of alien has a different Y coordinate
                //Second Array
                InvadersOne[Count] = new Invader();
                InvadersOne[Count].SetXPos(XPos);
                InvadersOne[Count].SetYPos(135);
                //Third Array
                InvadersTwo[Count] = new Invader();
                InvadersTwo[Count].SetXPos(XPos);
                InvadersTwo[Count].SetYPos(155);
                //Fourth Array
                InvadersThree[Count] = new Invader();
                InvadersThree[Count].SetXPos(XPos);
                InvadersThree[Count].SetYPos(180);
                //Fifth Array
                InvadersFour[Count] = new Invader();
                InvadersFour[Count].SetXPos(XPos);
                InvadersFour[Count].SetYPos(205);

                XPos = XPos + 32;
            }

            int BossXPos = 512;     //Sets defualt X position for Boss Alien
            BossAlien= new BossAlien();
            BossAlien.SetXPos(BossXPos);
            BossAlien.SetYPos(0);

            Ticks = 0; //Shows the amount of time passed
            Timer = 0; //Timer for each variable e.g. Alien & Boss
            Timer2 = 0;
            Timer3 = 0;
            Timer4 = 0;
            MissileFired = null;    //Missile values are set to null at start
            AlienMissileFired = null;
            AlienMissileFired2 = null;
            BossMissileFired = null;
            PlayerScore = 0;    //Player score set to 0 at start
            AmountofLives = 3; //Amount of lives the player at start of game
            BossLife = 3;     //Amount of lives Boss has at start of game
            WeaponsCount = 1; //Checks what weapon the player is using & allows switching between them
        }
Exemple #5
0
        protected void InitialiseGameVariables()
        {
            //initialise variables.

            GameLives  = 3;
            RocketXPos = 512;

            AlienDirection = -1;
            AlienSpeed     = 16;

            Invaders = new Invader[55];

            int XPos = 512;
            int posY = 100;
            int posX = 512;

            //Generating the invaders. 5 blocks of code for each row
            for (int Count = 0; Count < 11; Count++)
            {
                Invaders[Count] = new Invader();
                Invaders[Count].SetXPos(posX);
                Invaders[Count].SetYPos(posY);

                posX = posX + 32;
                XPos = XPos + 32;
            }
            //Resetting the X position
            posX = 512;

            for (int Count = 11; Count < 22; Count++)
            {
                posY            = 150;
                Invaders[Count] = new Invader();
                Invaders[Count].SetXPos(posX);
                Invaders[Count].SetYPos(posY);

                posX = posX + 32;
                XPos = XPos + 32;
            }

            posX = 512;

            for (int Count = 22; Count < 33; Count++)
            {
                posY            = 200;
                Invaders[Count] = new Invader();
                Invaders[Count].SetXPos(posX);
                Invaders[Count].SetYPos(posY);

                posX = posX + 32;
                XPos = XPos + 32;
            }
            posX = 512;

            for (int Count = 33; Count < 44; Count++)
            {
                posY            = 250;
                Invaders[Count] = new Invader();
                Invaders[Count].SetXPos(posX);
                Invaders[Count].SetYPos(posY);

                posX = posX + 32;
                XPos = XPos + 32;
            }
            posX = 512;

            for (int Count = 44; Count < 55; Count++)
            {
                posY            = 300;
                Invaders[Count] = new Invader();
                Invaders[Count].SetXPos(posX);
                Invaders[Count].SetYPos(posY);

                posX = posX + 32;
                XPos = XPos + 32;
            }


            //Setting More Game Variables & Instances
            Ticks        = 0;
            MissileFired = null;
            PlayerScore  = 0;
            ufo          = new UFO();
            base.Initialize();
            invaderMissile = null;
        }