Game.cs

using System;
using System.Drawing;

namespace Asteroids
{
	/// <summary>
	/// Summary description for CGame.
	/// </summary>
	public class Game : CommonOps
	{
      private Ship ship;
      private Bullet[] shipBullets;
      private AsteroidBelt asteroids;
      private Explosions explosions;
      private bool inProcess; 
      private int iLevel;
      private bool paused;
      const int PAUSE_INTERVAL = (int)(FPS);
      int iPauseTimer;
      
      public Game()
      {
         iLevel = 4; // start with 4 asteroids
         inProcess = true;
         ship = new Ship(true); // new game - we know ship is alive
         shipBullets = new Bullet[4];
         for (int i = 0; i<4; i++)
            shipBullets[i] = new Bullet();         
         asteroids = new AsteroidBelt(iLevel);
         explosions = new Explosions();
         paused = false;
         iPauseTimer = PAUSE_INTERVAL;
      }

      public bool Done()
      {
         return (!inProcess);
      }

      public void Thrust(bool bThrustOn)
      {
         if (!paused && ship.IsAlive())
         {
            ship.DecayThrust();
            if (bThrustOn)
               ship.Thrust();
         }
      }

      public void Left()
      {
         if (!paused && ship.IsAlive())
            ship.RotateLeft();
      }
		
      public void Right()
      {
         if (!paused && ship.IsAlive())
            ship.RotateRight();
      }

      public void Hyperspace()
      {   
         if (!paused && ship.IsAlive())
            if (!ship.Hyperspace())
               ExplodeShip();
      }

      public void Shoot()
      {
         if (!paused && ship.IsAlive())
         {
            foreach (Bullet bullet in shipBullets)
            {
               if (bullet.Available())
               {
                  bullet.Shoot(ship.GetCurrLoc(), ship.GetRadians(), ship.GetVelocityX(), ship.GetVelocityY());
                  PlaySound("Fire.WAV");
                  return;
               }
            }
         }
      }

      public void Pause()
      {
         iPauseTimer = PAUSE_INTERVAL;
         paused = !paused;
      }

      private bool CheckPointInAsteroid(Point ptCheck, ref Score score)
      {
         int pointValue = asteroids.CheckPointCollisions(ptCheck);
         if (pointValue > 0)
         {                  
            score.AddScore(pointValue);
            return true;
         }
         return false;
      }

      private void ExplodeShip()
      {
         Point ptCheck = new Point(0);
         PlaySound("EXPLODE1.WAV");
         PlaySound("EXPLODE2.WAV");
         PlaySound("EXPLODE3.WAV");
         foreach (Point ptExp in ship.pointsTransformed)
         {
            ship.Explode();
            ptCheck.X = ptExp.X + ship.GetCurrLoc().X;
            ptCheck.Y = ptExp.Y + ship.GetCurrLoc().Y;
            explosions.AddExplosion(ptCheck, 2);
         }
      }

      public void DrawScreen(ScreenCanvas sc, int iPictX, int iPictY, ref Score score)
      {
         Point ptCheck = new Point(0);

         if (paused)
         {
            // Pause flashes on and off
            if (iPauseTimer > PAUSE_INTERVAL/2)
            {
               TextDraw.DrawText(sc, "PAUSE", TextDraw.Justify.CENTER, 
                  iMaxY / 3, 200, 400, iPictX, iPictY);
            }
            if (--iPauseTimer < 0)
               iPauseTimer = PAUSE_INTERVAL;
         }
         else // Do all game processing if game is not paused
         {
            // If no ship displaying, after explosions are done
            // get a new one - or end the game
            if (!ship.IsAlive() && 
               (explosions.Count() == 0))
            {
               if (!score.HasReserveShips())
               {
                  // Game over
                  inProcess = false;
               }
               else
               {
                  if (asteroids.IsCenterSafe())
                  {
                     score.GetNewShip();
                     ship = new Ship(true);
                  }
               }
            }

            // Create a new asteroid belt if 
            // no explosions and no asteroids
            if ((explosions.Count() == 0) &&
               (asteroids.Count() == 0))
            {
               asteroids = new AsteroidBelt(++iLevel);
            }

            // Move all objects
            ship.Move();
            foreach (Bullet bullet in shipBullets)
            {
               bullet.Move();
            }
            asteroids.Move();
            explosions.Move();

            // Check bullets for collisions         
            foreach (Bullet bullet in shipBullets)
            {
               if (bullet.AcquireLoc(ref ptCheck) &&
                  CheckPointInAsteroid(ptCheck, ref score))
               {
                  explosions.AddExplosion(ptCheck);
                  bullet.Disable();
               }
            }

            // Check ship for collisions
            if (ship.IsAlive())
            {
               foreach (Point ptInShip in ship.pointsTransformed)
               {
                  ptCheck.X = ptInShip.X + ship.GetCurrLoc().X;
                  ptCheck.Y = ptInShip.Y + ship.GetCurrLoc().Y;
                  if (CheckPointInAsteroid(ptCheck, ref score))
                  {
                     ExplodeShip();
                     break;
                  }
               }
            }
         }

         // Draw all objects
         ship.Draw(sc, iPictX, iPictY);         
         foreach (Bullet bullet in shipBullets)
         {
            bullet.Draw(sc, iPictX, iPictY);
         }

         asteroids.Draw(sc, iPictX, iPictY);
         explosions.Draw(sc, iPictX, iPictY);

         // Draw the score
         score.Draw(sc, iPictX, iPictY);
      }
	}
}