/// <summary>
/// Update projectile
/// </summary>
public bool Update(float elapsedTime, GameManager game)
{
if (game == null)
{
throw new ArgumentNullException("game");
}
// add elapsed time for this frame
this.elapsedTime += elapsedTime;
// normalize time
float normalizedTime = Math.Min(1.0f, this.elapsedTime / totalTime);
// compute current projectile position
Vector3 position = Vector3.Lerp(sourcePosition, destinationPosition,
normalizedTime);
// set postion into projectile transform matrix
transform.Translation = position;
// if projectile includes a particle system update its position
if (system != null)
system.SetTransform(systemTransform * transform);
// check if projectile hit any player
int playerHit = game.GetPlayerAtPosition(position);
// if a player is hit or reached destination explode projectile
if ((playerHit != player && playerHit != -1) ||
normalizedTime == 1.0f)
{
// compute explosion position moving hit point into hit normal direction
Vector3 explosionPosition =
position + 0.5f * animatedSpriteSize * transform.Backward;
// set transform to explosion position
transform.Translation = explosionPosition;
// if an animated sprite explosion is available, create it
if (animatedSpriteSize > 0)
game.AddAnimSprite(animatedSprite, explosionPosition,
animatedSpriteSize, 10.0f, animatedSpriteFrameRate,
animatedSpriteDrawMode, -1);
// if splash damage is available, apply splash damage to nearby players
if (explosionDamageRadius > 0)
game.AddDamageSplash(player, explosionDamage,
explosionPosition, explosionDamageRadius);
// if exploded on a player add contact damage
if (playerHit != -1 && game.GetPlayer(playerHit).IsAlive)
game.AddDamage(player, playerHit, contactDamage,
Vector3.Normalize(destinationPosition - sourcePosition));
// if explosion sound is available, play it
if (explosionSound != null)
game.PlaySound3D(explosionSound, explosionPosition);
// add explosion particle system
if (projectileType == ProjectileType.Missile)
game.AddParticleSystem(
ParticleSystemType.MissileExplode,
transform);
else
if (projectileType == ProjectileType.Blaster)
game.AddParticleSystem(
ParticleSystemType.BlasterExplode,
transform);
// kill trail particle system
if (system != null)
system.SetTotalTime(-1e10f);
// return false to kill the projectile
return false;
}
// return true to keep projectile alive
return true;
}
/// <summary>
/// Update powerup for given elapsed time
/// </summary>
public bool Update(GameManager game, float elapsedTime)
{
if (game == null)
{
throw new ArgumentNullException("game");
}
// add elapsed time for this frame
this.elapsedTime += elapsedTime;
// if waiting to respawn
if (waitTime > 0)
{
// decrease wait time
waitTime = Math.Max(0.0f, waitTime - elapsedTime);
// if wait time is finished
if (waitTime == 0)
{
// add powerup spawn animated sprite
game.AddAnimSprite(AnimSpriteType.Spawn,
transform.Translation, 50, 40, 30, DrawMode.Additive, -1);
// play powerup spawn sound
game.PlaySound3D("powerup_spawn", transform.Translation);
}
// return true to keep powerup alive
return true;
}
// calculate bobbing angles
float turn_angle = (this.elapsedTime * GameOptions.PowerupTurnSpeed) %
MathHelper.TwoPi;
float move_angle = (this.elapsedTime * GameOptions.PowerupMoveSpeed) %
MathHelper.TwoPi;
// create bobbing matrix
bobbing = Matrix.CreateRotationY(turn_angle) *
Matrix.CreateTranslation((float)Math.Cos(move_angle) *
GameOptions.PowerupMoveDistance * Vector3.Up);
// check for any player at the powerup location
int playerHit = game.GetPlayerAtPosition(transform.Translation);
if (playerHit != -1)
{
// disable powerup until respawn time
waitTime = GameOptions.PowerupRespawnTime;
// get player at powerup location
PlayerShip p = game.GetPlayer(playerHit);
switch( powerupType )
{
case PowerupType.Energy:
p.AddEnergy(0.5f); // add 50% energy
break;
case PowerupType.Missile:
p.AddMissile(3); // add 3 missiles
break;
}
// add powerup spawn animates sprite
game.AddAnimSprite(AnimSpriteType.Spawn,
transform.Translation, 40, 40, 30, DrawMode.Additive, -1);
// play powerup get sound
game.PlaySound("powerup_get");
}
// return true to keep powerup alive
return true;
}