public virtual void Update(LevelTime levelTime)
{
songPosition = levelTime.SongPosition; // used in draw call
/* I'm either insane or insanely brilliant, but it's probably the former.
* The problem: Replays kept desyncing because spawner movement was still
* framerate-dependent due to accumulating floating point errors
* (or something like that).
* A normal person would've just locked the update loop to n ticks/s
* and called it a day, but in MonoGame, as far as I'm aware,
* that also caps the framerate at n fps, and I didn't want to do that.
* Instead, I decided to calculate the spawner positions independent of
* game state to sidestep this problem.
* To do this, I turn the SR and TW node lists into piecewise functions,
* multiply them to get a combined movement function, and then,
* for each frame, multiply the rotation/ms factor by the integral
* of that function between 0 and the current song position.
* This appears to have sorted out my issues for the most part. Spawner
* movement still varies a little bit in moments with high SR*TW values,
* but since these variances don't accumulate anymore, it always
* catches itself when the rotation slows down.
*/
var totalIntegral = combinedSpinWarpFunction.IntegralTo(songPosition);
for (int i = 0; i < Spawners.Count; i++)
{
var spawner = Spawners[i];
if (spawner.IsStillInUse(levelTime.SongPosition) || spawner.ActiveFlares.Count > 0)
{
spawner.Angle = (float)(spawnerAngles[i]
+ MathEx.WrapAngle(totalIntegral * Spawner.RotationPerMs));
spawner.Update(levelTime);
}
}
}
/// <summary>
/// Creates one wave of a shot.
/// </summary>
public List <Bullet> Create(Vector2 spawnPoint, float spawnerAngle, Vector2 playerCenter,
LevelColors colors)
{
var bullets = new List <Bullet>(Amount);
double waveAngle = spawnerAngle + (90 * MathEx.DegToRad);
if (Amount > 1)
{
waveAngle += Angle / -2;
}
if (Aim == Aim.Player)
{
float playerAngle = (float)Math.Atan2(
spawnPoint.Y - playerCenter.Y,
spawnPoint.X - playerCenter.X)
- spawnerAngle;
waveAngle += playerAngle;
}
MathEx.WrapAngle(waveAngle);
var angleStep = Angle / (Amount - 1);
for (int i = 0; i < Amount; i++)
{
var bulletAngle = waveAngle + Offset;
if (BulletType == BulletType.Homing)
{
bullets.Add(CreateHomingBullet(spawnPoint, (float)bulletAngle,
(float)Speed, (float)HomingLifespan, colors));
}
else
{
bullets.Add(CreateBullet(BulletType, spawnPoint, (float)bulletAngle,
(float)Speed, colors));
}
waveAngle += angleStep;
}
return(bullets);
}