public GamePlayEngine.State UpdateState(GamePlayEngine.State currentState, float deltaTime)
{
var enemies = currentState.Enemies;
var state = currentState;
var remainEnemies = new List <IEnemy>();
var bulletStates = currentState.Bullets
.Select(bullet => (bullet, nextBullet: bullet.Move(deltaTime))).ToList();
foreach (var enemy in enemies)
{
var currentEnemy = enemy;
var bullets = state.Bullets;
var remainBullets = new List <(IBullet bullet, IBullet nextBullet)>();
foreach (var bulletPair in bulletStates)
{
var moveRange = GamePlayEngine.GetMoveRange(bulletPair.bullet.AreaRange, bulletPair.nextBullet.AreaRange);
if (!currentEnemy.IsDead() && currentEnemy.AreaRange.IsIntersect(moveRange))
{
currentEnemy = currentEnemy.BeInjured(bulletPair.bullet.Atk);
}
else if (bulletPair.nextBullet.AreaRange.IsIntersect(state.PlayRange))
{
remainBullets.Add(bulletPair);
}
}
if (currentEnemy.IsDead())
{
state = state.With(
s => s.Score,
state.Score + currentEnemy.Score);
}
else
{
remainEnemies.Add(currentEnemy);
}
bulletStates = remainBullets;
}
return(state.With(
s => s.Enemies,
remainEnemies.ToArray())
.With(
s => s.Bullets,
bulletStates.Select(bulletPair => bulletPair.nextBullet).ToArray()));
}
GamePlayEngine.State ICommand.Execute(GamePlayEngine.State state)
=> state.With(
s => s.Bullets,
state.Bullets.Concat(new IBullet[] { state.Player.Attack() }).ToArray());
GamePlayEngine.State ICommand.Execute(GamePlayEngine.State state)
=> state.With(
s => s.Player,
state.Player.Jump());