private static IEnumerator<bool> LazyHomingToEnemy(PlayerUser par, PlayerBullet b, double startAngle, double startSpeed, int delay, double homingSpeed)
{
for (int i = 0; i < delay; i++)
{
b.X += Math.Cos(startAngle) * startSpeed;
b.Y += Math.Sin(startAngle) * startSpeed;
yield return true;
}
var t = par.ParentManager
.Where(p => p.MyKind != b.MyKind && ((p.DamageKind & b.MyKind) != 0))
.OrderBy(p => (p.X - b.X) * (p.X - b.X) + (p.Y - b.Y) * (p.Y - b.Y))
.FirstOrDefault();
var ang = 0.0;
if (t == null)
{
ang = rnd.NextDouble() * Math.PI * 2;
}
else
{
ang = Math.Atan2(t.Y - b.Y, t.X - b.X);
}
while (true)
{
b.X += Math.Cos(ang) * homingSpeed;
b.Y += Math.Sin(ang) * homingSpeed;
yield return true;
}
}
private static IEnumerator<bool> Linear(UserSprite par, PlayerBullet b, double angle, double speed, int time)
{
for (int i = 0; i < time; i++)
{
b.X += Math.Cos(angle) * speed;
b.Y += Math.Sin(angle) * speed;
yield return true;
}
b.IsDead = true;
yield break;
}
private static IEnumerator<bool> HomingFunction(UserSprite us, PlayerBullet b)
{
var speed = 12.0;
var curve = 0.03;
var tl = us.ParentManager.OfType<EnemyUser>()
.OrderBy(p =>
{
var x = p.X - b.X;
var y = p.Y - b.Y;
return Math.Sqrt(x * x + y * y);
}).FirstOrDefault();
var hm = tl != null;
while (true)
{
if (hm && !tl.IsDead)
{
var ta = Math.Atan2(tl.Y - b.Y, tl.X - b.X) - b.Angle;
if (ta <= 0)
{
b.Angle -= curve;
}
else
{
b.Angle += curve;
}
}
b.X += Math.Cos(b.Angle) * speed;
b.Y += Math.Sin(b.Angle) * speed;
yield return true;
}
}