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osu-lazer/osu.Game/Graphics/Containers/BeatSyncedContainer.cs
2022-05-22 22:44:54 +09:00

144 lines
6.0 KiB
C#

// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.
using System;
using System.Diagnostics;
using osu.Framework.Allocation;
using osu.Framework.Audio.Track;
using osu.Framework.Graphics.Containers;
using osu.Game.Beatmaps;
using osu.Game.Beatmaps.ControlPoints;
using osu.Game.Screens.Play;
namespace osu.Game.Graphics.Containers
{
/// <summary>
/// A container which fires a callback when a new beat is reached.
/// Consumes a parent <see cref="GameplayClock"/> or <see cref="Beatmap"/> (whichever is first available).
/// </summary>
/// <remarks>
/// This container does not set its own clock to the source used for beat matching.
/// This means that if the beat source clock is playing faster or slower, animations may unexpectedly overlap.
/// Make sure this container's Clock is also set to the expected source (or within a parent element which provides this).
///
/// This container will also trigger beat events when the beat matching clock is paused at <see cref="TimingControlPoint.DEFAULT"/>'s BPM.
/// </remarks>
public class BeatSyncedContainer : Container
{
private int lastBeat;
private TimingControlPoint lastTimingPoint;
/// <summary>
/// The amount of time before a beat we should fire <see cref="OnNewBeat(int, TimingControlPoint, EffectControlPoint, ChannelAmplitudes)"/>.
/// This allows for adding easing to animations that may be synchronised to the beat.
/// </summary>
protected double EarlyActivationMilliseconds;
/// <summary>
/// While this container automatically applied an animation delay (meaning any animations inside a <see cref="OnNewBeat"/> implementation will
/// always be correctly timed), the event itself can potentially fire away from the related beat.
///
/// By setting this to false, cases where the event is to be fired more than <see cref="MISTIMED_ALLOWANCE"/> from the related beat will be skipped.
/// </summary>
protected bool AllowMistimedEventFiring = true;
/// <summary>
/// The maximum deviance from the actual beat that an <see cref="OnNewBeat"/> can fire when <see cref="AllowMistimedEventFiring"/> is set to false.
/// </summary>
public const double MISTIMED_ALLOWANCE = 16;
/// <summary>
/// The time in milliseconds until the next beat.
/// </summary>
public double TimeUntilNextBeat { get; private set; }
/// <summary>
/// The time in milliseconds since the last beat
/// </summary>
public double TimeSinceLastBeat { get; private set; }
/// <summary>
/// How many beats per beatlength to trigger. Defaults to 1.
/// </summary>
public int Divisor { get; set; } = 1;
/// <summary>
/// An optional minimum beat length. Any beat length below this will be multiplied by two until valid.
/// </summary>
public double MinimumBeatLength { get; set; }
/// <summary>
/// Whether this container is currently tracking a beatmap's timing data.
/// </summary>
protected bool IsBeatSyncedWithTrack { get; private set; }
[Resolved]
protected IBeatSyncProvider BeatSyncSource { get; private set; }
protected virtual void OnNewBeat(int beatIndex, TimingControlPoint timingPoint, EffectControlPoint effectPoint, ChannelAmplitudes amplitudes)
{
}
protected override void Update()
{
TimingControlPoint timingPoint;
EffectControlPoint effectPoint;
IsBeatSyncedWithTrack = BeatSyncSource.Clock?.IsRunning == true;
double currentTrackTime;
if (IsBeatSyncedWithTrack)
{
Debug.Assert(BeatSyncSource.ControlPoints != null);
Debug.Assert(BeatSyncSource.Clock != null);
currentTrackTime = BeatSyncSource.Clock.CurrentTime + EarlyActivationMilliseconds;
timingPoint = BeatSyncSource.ControlPoints.TimingPointAt(currentTrackTime);
effectPoint = BeatSyncSource.ControlPoints.EffectPointAt(currentTrackTime);
}
else
{
// this may be the case where the beat syncing clock has been paused.
// we still want to show an idle animation, so use this container's time instead.
currentTrackTime = Clock.CurrentTime + EarlyActivationMilliseconds;
timingPoint = TimingControlPoint.DEFAULT;
effectPoint = EffectControlPoint.DEFAULT;
}
double beatLength = timingPoint.BeatLength / Divisor;
while (beatLength < MinimumBeatLength)
beatLength *= 2;
int beatIndex = (int)((currentTrackTime - timingPoint.Time) / beatLength) - (effectPoint.OmitFirstBarLine ? 1 : 0);
// The beats before the start of the first control point are off by 1, this should do the trick
if (currentTrackTime < timingPoint.Time)
beatIndex--;
TimeUntilNextBeat = (timingPoint.Time - currentTrackTime) % beatLength;
if (TimeUntilNextBeat <= 0)
TimeUntilNextBeat += beatLength;
TimeSinceLastBeat = beatLength - TimeUntilNextBeat;
if (timingPoint == lastTimingPoint && beatIndex == lastBeat)
return;
// as this event is sometimes used for sound triggers where `BeginDelayedSequence` has no effect, avoid firing it if too far away from the beat.
// this can happen after a seek operation.
if (AllowMistimedEventFiring || Math.Abs(TimeSinceLastBeat) < MISTIMED_ALLOWANCE)
{
using (BeginDelayedSequence(-TimeSinceLastBeat))
OnNewBeat(beatIndex, timingPoint, effectPoint, BeatSyncSource.Amplitudes ?? ChannelAmplitudes.Empty);
}
lastBeat = beatIndex;
lastTimingPoint = timingPoint;
}
}
}