osu/osu.Game/Rulesets/UI/FrameStabilityContainer.cs

192 lines
6.7 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 osu.Framework.Allocation;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Timing;
using osu.Game.Input.Handlers;
using osu.Game.Screens.Play;
namespace osu.Game.Rulesets.UI
{
/// <summary>
/// A container which consumes a parent gameplay clock and standardises frame counts for children.
/// Will ensure a minimum of 40 frames per clock second is maintained, regardless of any system lag or seeks.
/// </summary>
public class FrameStabilityContainer : Container, IHasReplayHandler
{
private readonly double gameplayStartTime;
/// <summary>
/// The number of frames (per parent frame) which can be run in an attempt to catch-up to real-time.
/// </summary>
public int MaxCatchUpFrames { get; set; } = 5;
/// <summary>
/// Whether to enable frame-stable playback.
/// </summary>
internal bool FrameStablePlayback = true;
[Cached]
public GameplayClock GameplayClock { get; }
public FrameStabilityContainer(double gameplayStartTime = double.MinValue)
{
RelativeSizeAxes = Axes.Both;
GameplayClock = new GameplayClock(framedClock = new FramedClock(manualClock = new ManualClock()));
this.gameplayStartTime = gameplayStartTime;
}
private readonly ManualClock manualClock;
private readonly FramedClock framedClock;
private IFrameBasedClock parentGameplayClock;
/// <summary>
/// The current direction of playback to be exposed to frame stable children.
/// </summary>
private int direction;
[BackgroundDependencyLoader(true)]
private void load(GameplayClock clock)
{
if (clock != null)
{
parentGameplayClock = clock;
GameplayClock.IsPaused.BindTo(clock.IsPaused);
}
}
protected override void LoadComplete()
{
base.LoadComplete();
setClock();
}
/// <summary>
/// Whether we are running up-to-date with our parent clock.
/// If not, we will need to keep processing children until we catch up.
/// </summary>
private bool requireMoreUpdateLoops;
/// <summary>
/// Whether we are in a valid state (ie. should we keep processing children frames).
/// This should be set to false when the replay is, for instance, waiting for future frames to arrive.
/// </summary>
private bool validState;
protected override bool RequiresChildrenUpdate => base.RequiresChildrenUpdate && validState;
private bool isAttached => ReplayInputHandler != null;
private const double sixty_frame_time = 1000.0 / 60;
private bool firstConsumption = true;
public override bool UpdateSubTree()
{
requireMoreUpdateLoops = true;
validState = !GameplayClock.IsPaused.Value;
int loops = 0;
while (validState && requireMoreUpdateLoops && loops++ < MaxCatchUpFrames)
{
updateClock();
if (validState)
{
base.UpdateSubTree();
UpdateSubTreeMasking(this, ScreenSpaceDrawQuad.AABBFloat);
}
}
return true;
}
private void updateClock()
{
if (parentGameplayClock == null)
setClock(); // LoadComplete may not be run yet, but we still want the clock.
validState = true;
requireMoreUpdateLoops = false;
var newProposedTime = parentGameplayClock.CurrentTime;
try
{
if (!FrameStablePlayback)
return;
if (firstConsumption)
{
// On the first update, frame-stability seeking would result in unexpected/unwanted behaviour.
// Instead we perform an initial seek to the proposed time.
// process frame (in addition to finally clause) to clear out ElapsedTime
manualClock.CurrentTime = newProposedTime;
framedClock.ProcessFrame();
firstConsumption = false;
}
else if (manualClock.CurrentTime < gameplayStartTime)
manualClock.CurrentTime = newProposedTime = Math.Min(gameplayStartTime, newProposedTime);
else if (Math.Abs(manualClock.CurrentTime - newProposedTime) > sixty_frame_time * 1.2f)
{
newProposedTime = newProposedTime > manualClock.CurrentTime
? Math.Min(newProposedTime, manualClock.CurrentTime + sixty_frame_time)
: Math.Max(newProposedTime, manualClock.CurrentTime - sixty_frame_time);
}
if (isAttached)
{
double? newTime = ReplayInputHandler.SetFrameFromTime(newProposedTime);
if (newTime == null)
{
// we shouldn't execute for this time value. probably waiting on more replay data.
validState = false;
requireMoreUpdateLoops = true;
return;
}
newProposedTime = newTime.Value;
}
}
finally
{
if (newProposedTime != manualClock.CurrentTime)
direction = newProposedTime > manualClock.CurrentTime ? 1 : -1;
manualClock.CurrentTime = newProposedTime;
manualClock.Rate = Math.Abs(parentGameplayClock.Rate) * direction;
manualClock.IsRunning = parentGameplayClock.IsRunning;
requireMoreUpdateLoops |= manualClock.CurrentTime != parentGameplayClock.CurrentTime;
// The manual clock time has changed in the above code. The framed clock now needs to be updated
// to ensure that the its time is valid for our children before input is processed
framedClock.ProcessFrame();
}
}
private void setClock()
{
// in case a parent gameplay clock isn't available, just use the parent clock.
if (parentGameplayClock == null)
parentGameplayClock = Clock;
Clock = GameplayClock;
ProcessCustomClock = false;
}
public ReplayInputHandler ReplayInputHandler { get; set; }
}
}