osu/osu.Game/Screens/Play/GameplayClockContainer.cs

249 lines
8.6 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.Collections.Generic;
using System.Linq;
using osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Logging;
using osu.Framework.Timing;
using osu.Framework.Utils;
namespace osu.Game.Screens.Play
{
/// <summary>
/// Encapsulates gameplay timing logic and provides a <see cref="IGameplayClock"/> via DI for gameplay components to use.
/// </summary>
public class GameplayClockContainer : Container, IAdjustableClock, IGameplayClock
{
/// <summary>
/// Whether gameplay is paused.
/// </summary>
public IBindable<bool> IsPaused => isPaused;
/// <summary>
/// The source clock. Should generally not be used for any timekeeping purposes.
/// </summary>
public IClock SourceClock { get; private set; }
/// <summary>
/// Invoked when a seek has been performed via <see cref="Seek"/>
/// </summary>
public event Action? OnSeek;
/// <summary>
/// The time from which the clock should start. Will be seeked to on calling <see cref="Reset"/>.
/// </summary>
/// <remarks>
/// If not set, a value of zero will be used.
/// Importantly, the value will be inferred from the current ruleset in <see cref="MasterGameplayClockContainer"/> unless specified.
/// </remarks>
public double? StartTime { get; set; }
public virtual IEnumerable<double> NonGameplayAdjustments => Enumerable.Empty<double>();
/// <summary>
/// The final clock which is exposed to gameplay components.
/// </summary>
protected IFrameBasedClock FramedClock { get; private set; }
private readonly BindableBool isPaused = new BindableBool(true);
/// <summary>
/// The adjustable source clock used for gameplay. Should be used for seeks and clock control.
/// </summary>
private readonly DecoupleableInterpolatingFramedClock decoupledClock;
/// <summary>
/// Creates a new <see cref="GameplayClockContainer"/>.
/// </summary>
/// <param name="sourceClock">The source <see cref="IClock"/> used for timing.</param>
public GameplayClockContainer(IClock sourceClock)
{
SourceClock = sourceClock;
RelativeSizeAxes = Axes.Both;
decoupledClock = new DecoupleableInterpolatingFramedClock { IsCoupled = false };
IsPaused.BindValueChanged(OnIsPausedChanged);
// this will be replaced during load, but non-null for tests which don't add this component to the hierarchy.
FramedClock = new FramedClock();
}
protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent)
{
var dependencies = new DependencyContainer(base.CreateChildDependencies(parent));
FramedClock = CreateGameplayClock(decoupledClock);
dependencies.CacheAs<IGameplayClock>(this);
return dependencies;
}
/// <summary>
/// Starts gameplay.
/// </summary>
public virtual void Start()
{
ensureSourceClockSet();
if (!decoupledClock.IsRunning)
{
// Seeking the decoupled clock to its current time ensures that its source clock will be seeked to the same time
// This accounts for the clock source potentially taking time to enter a completely stopped state
Seek(FramedClock.CurrentTime);
decoupledClock.Start();
}
isPaused.Value = false;
}
/// <summary>
/// Seek to a specific time in gameplay.
/// </summary>
/// <param name="time">The destination time to seek to.</param>
public virtual void Seek(double time)
{
Logger.Log($"{nameof(GameplayClockContainer)} seeking to {time}");
decoupledClock.Seek(time);
// Manually process to make sure the gameplay clock is correctly updated after a seek.
FramedClock.ProcessFrame();
OnSeek?.Invoke();
}
/// <summary>
/// Stops gameplay.
/// </summary>
public void Stop() => isPaused.Value = true;
/// <summary>
/// Resets this <see cref="GameplayClockContainer"/> and the source to an initial state ready for gameplay.
/// </summary>
/// <param name="startClock">Whether to start the clock immediately, if not already started.</param>
public void Reset(bool startClock = false)
{
// Manually stop the source in order to not affect the IsPaused state.
decoupledClock.Stop();
if (!IsPaused.Value || startClock)
Start();
ensureSourceClockSet();
Seek(StartTime ?? 0);
}
/// <summary>
/// Changes the source clock.
/// </summary>
/// <param name="sourceClock">The new source.</param>
protected void ChangeSource(IClock sourceClock) => decoupledClock.ChangeSource(SourceClock = sourceClock);
/// <summary>
/// Ensures that the <see cref="decoupledClock"/> is set to <see cref="SourceClock"/>, if it hasn't been given a source yet.
/// This is usually done before a seek to avoid accidentally seeking only the adjustable source in decoupled mode,
/// but not the actual source clock.
/// That will pretty much only happen on the very first call of this method, as the source clock is passed in the constructor,
/// but it is not yet set on the adjustable source there.
/// </summary>
private void ensureSourceClockSet()
{
if (decoupledClock.Source == null)
ChangeSource(SourceClock);
}
protected override void Update()
{
if (!IsPaused.Value)
FramedClock.ProcessFrame();
base.Update();
}
/// <summary>
/// Invoked when the value of <see cref="IsPaused"/> is changed to start or stop the <see cref="decoupledClock"/> clock.
/// </summary>
/// <param name="isPaused">Whether the clock should now be paused.</param>
protected virtual void OnIsPausedChanged(ValueChangedEvent<bool> isPaused)
{
if (isPaused.NewValue)
decoupledClock.Stop();
else
decoupledClock.Start();
}
/// <summary>
/// Creates the final <see cref="FramedClock"/> which is exposed via DI to be used by gameplay components.
/// </summary>
/// <remarks>
/// Any intermediate clocks such as platform offsets should be applied here.
/// </remarks>
/// <param name="source">The <see cref="IFrameBasedClock"/> providing the source time.</param>
/// <returns>The final <see cref="FramedClock"/>.</returns>
protected virtual IFrameBasedClock CreateGameplayClock(IFrameBasedClock source) => source;
#region IAdjustableClock
bool IAdjustableClock.Seek(double position)
{
Seek(position);
return true;
}
void IAdjustableClock.Reset() => Reset();
public void ResetSpeedAdjustments() => throw new NotImplementedException();
double IAdjustableClock.Rate
{
get => FramedClock.Rate;
set => throw new NotSupportedException();
}
public double Rate => FramedClock.Rate;
public double CurrentTime => FramedClock.CurrentTime;
public bool IsRunning => FramedClock.IsRunning;
#endregion
public void ProcessFrame()
{
// Handled via update. Don't process here to safeguard from external usages potentially processing frames additional times.
}
public double ElapsedFrameTime => FramedClock.ElapsedFrameTime;
public double FramesPerSecond => FramedClock.FramesPerSecond;
public FrameTimeInfo TimeInfo => FramedClock.TimeInfo;
public double TrueGameplayRate
{
get
{
double baseRate = Rate;
foreach (double adjustment in NonGameplayAdjustments)
{
if (Precision.AlmostEquals(adjustment, 0))
return 0;
baseRate /= adjustment;
}
return baseRate;
}
}
}
}