protected override void Update(GameTime gameTime)
{
// Allows the game to exit
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
{
this.Exit();
}
// update our virtual thumbsticks
VirtualThumbsticks.Update();
// countdown until we spawn more enemies
spawnTimer -= gameTime.ElapsedGameTime;
if (spawnTimer <= TimeSpan.Zero)
{
// we spawn 1-3 enemies per spawn
int numToSpawn = rand.Next(1, 3);
for (int i = 0; i < numToSpawn; i++)
{
// create the enemy
EnemyShip enemy = new EnemyShip(Content.Load <Texture2D>("alien"));
// target the player's ship
enemy.Player = player;
// we randomly pick either the left or right side of the screen
// to place the enemy
if (rand.Next() % 2 == 0)
{
enemy.Position.X = -worldWidth / 2f - (graphicsWidthHalf + 10);
}
else
{
enemy.Position.X = worldWidth / 2f + (graphicsWidthHalf + 10);
}
// we randomly pick either the top or bottom side of the screen
// to place the enemy
if (rand.Next() % 2 == 0)
{
enemy.Position.Y = -worldHeight / 2f - (graphicsHeightHalf + 10);
}
else
{
enemy.Position.Y = worldHeight / 2f + (graphicsHeightHalf + 10);
}
// add the enemy to our list
enemies.Add(enemy);
}
// reset our timer
spawnTimer = spawnRate;
}
// update the player
player.Update(gameTime);
// update all the enemies
foreach (var enemy in enemies)
{
enemy.Update(gameTime);
}
// create a couple lists to hold the bullets and enemies
// we need to remove due to collisions
List <Bullet> bulletsToRemove = new List <Bullet>();
List <EnemyShip> enemiesToRemove = new List <EnemyShip>();
// figure out what bullets and enemies are colliding
foreach (var b in player.Bullets)
{
foreach (var e in enemies)
{
// check if the enemy contains the bullet's position
if (e.ContainsPoint(b.Position))
{
// add the bullet and enemy to the lists to be removed
bulletsToRemove.Add(b);
enemiesToRemove.Add(e);
// break the inner loop so bullets only collide
// with one enemy
break;
}
}
}
// remove all marked bullets and enemies
foreach (var b in bulletsToRemove)
{
player.Bullets.Remove(b);
}
foreach (var e in enemiesToRemove)
{
enemies.Remove(e);
}
base.Update(gameTime);
}
protected override void Update(GameTime gameTime)
{
// Allows the game to exit
if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
this.Exit();
// update our virtual thumbsticks
VirtualThumbsticks.Update();
// countdown until we spawn more enemies
spawnTimer -= gameTime.ElapsedGameTime;
if (spawnTimer <= TimeSpan.Zero)
{
// we spawn 1-3 enemies per spawn
int numToSpawn = rand.Next(1, 3);
for (int i = 0; i < numToSpawn; i++)
{
// create the enemy
EnemyShip enemy = new EnemyShip(Content.Load<Texture2D>("alien"));
// target the player's ship
enemy.Player = player;
// we randomly pick either the left or right side of the screen
// to place the enemy
if (rand.Next() % 2 == 0)
{
enemy.Position.X = -worldWidth / 2f - (graphicsWidthHalf + 10);
}
else
{
enemy.Position.X = worldWidth / 2f + (graphicsWidthHalf + 10);
}
// we randomly pick either the top or bottom side of the screen
// to place the enemy
if (rand.Next() % 2 == 0)
{
enemy.Position.Y = -worldHeight / 2f - (graphicsHeightHalf + 10);
}
else
{
enemy.Position.Y = worldHeight / 2f + (graphicsHeightHalf + 10);
}
// add the enemy to our list
enemies.Add(enemy);
}
// reset our timer
spawnTimer = spawnRate;
}
// update the player
player.Update(gameTime);
// update all the enemies
foreach (var enemy in enemies)
enemy.Update(gameTime);
// create a couple lists to hold the bullets and enemies
// we need to remove due to collisions
List<Bullet> bulletsToRemove = new List<Bullet>();
List<EnemyShip> enemiesToRemove = new List<EnemyShip>();
// figure out what bullets and enemies are colliding
foreach (var b in player.Bullets)
{
foreach (var e in enemies)
{
// check if the enemy contains the bullet's position
if (e.ContainsPoint(b.Position))
{
// add the bullet and enemy to the lists to be removed
bulletsToRemove.Add(b);
enemiesToRemove.Add(e);
// break the inner loop so bullets only collide
// with one enemy
break;
}
}
}
// remove all marked bullets and enemies
foreach (var b in bulletsToRemove)
player.Bullets.Remove(b);
foreach (var e in enemiesToRemove)
enemies.Remove(e);
base.Update(gameTime);
}