// 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. #nullable enable using System; using System.Collections.Generic; using System.Linq; using osu.Game.Input.Handlers; using osu.Game.Replays; namespace osu.Game.Rulesets.Replays { /// <summary> /// The ReplayHandler will take a replay and handle the propagation of updates to the input stack. /// It handles logic of any frames which *must* be executed. /// </summary> public abstract class FramedReplayInputHandler<TFrame> : ReplayInputHandler where TFrame : ReplayFrame { /// <summary> /// Whether we have at least one replay frame. /// </summary> public bool HasFrames => Frames.Count != 0; /// <summary> /// Whether we are waiting for new frames to be received. /// </summary> public bool WaitingForFrame => !replay.HasReceivedAllFrames && currentFrameIndex == Frames.Count - 1; /// <summary> /// The current frame of the replay. /// The current time is always between the start and the end time of the current frame. /// </summary> /// <remarks>Returns null if the current time is strictly before the first frame.</remarks> public TFrame? CurrentFrame => currentFrameIndex == -1 ? null : (TFrame)Frames[currentFrameIndex]; /// <summary> /// The next frame of the replay. /// The start time of <see cref="NextFrame"/> is always greater or equal to the start time of <see cref="CurrentFrame"/> regardless of the seeking direction. /// </summary> /// <remarks>Returns null if the current frame is the last frame.</remarks> public TFrame? NextFrame => currentFrameIndex == Frames.Count - 1 ? null : (TFrame)Frames[currentFrameIndex + 1]; /// <summary> /// The frame for the start value of the interpolation of the replay movement. /// </summary> /// <exception cref="InvalidOperationException">The replay is empty.</exception> public TFrame StartFrame { get { if (!HasFrames) throw new InvalidOperationException($"Attempted to get {nameof(StartFrame)} of an empty replay"); return (TFrame)Frames[Math.Max(0, currentFrameIndex)]; } } /// <summary> /// The frame for the end value of the interpolation of the replay movement. /// </summary> /// <exception cref="InvalidOperationException">The replay is empty.</exception> public TFrame EndFrame { get { if (!HasFrames) throw new InvalidOperationException($"Attempted to get {nameof(EndFrame)} of an empty replay"); return (TFrame)Frames[Math.Min(currentFrameIndex + 1, Frames.Count - 1)]; } } /// <summary> /// When set, we will ensure frames executed by nested drawables are frame-accurate to replay data. /// Disabling this can make replay playback smoother (useful for autoplay, currently). /// </summary> public bool FrameAccuratePlayback; // This input handler should be enabled only if there is at least one replay frame. public override bool IsActive => HasFrames; protected double CurrentTime { get; private set; } protected virtual double AllowedImportantTimeSpan => sixty_frame_time * 1.2; protected List<ReplayFrame> Frames => replay.Frames; private readonly Replay replay; private int currentFrameIndex; private const double sixty_frame_time = 1000.0 / 60; protected FramedReplayInputHandler(Replay replay) { // TODO: This replay frame ordering should be enforced on the Replay type. // Currently, the ordering can be broken if the frames are added after this construction. replay.Frames = replay.Frames.OrderBy(f => f.Time).ToList(); this.replay = replay; currentFrameIndex = -1; CurrentTime = double.NegativeInfinity; } private bool inImportantSection { get { if (!HasFrames || !FrameAccuratePlayback || currentFrameIndex == -1) return false; return IsImportant(StartFrame) && // a button is in a pressed state Math.Abs(CurrentTime - EndFrame.Time) <= AllowedImportantTimeSpan; // the next frame is within an allowable time span } } protected virtual bool IsImportant(TFrame frame) => false; /// <summary> /// Update the current frame based on an incoming time value. /// There are cases where we return a "must-use" time value that is different from the input. /// This is to ensure accurate playback of replay data. /// </summary> /// <param name="time">The time which we should use for finding the current frame.</param> /// <returns>The usable time value. If null, we should not advance time as we do not have enough data.</returns> public override double? SetFrameFromTime(double time) { if (!HasFrames) { // In the case all frames are received, allow time to progress regardless. if (replay.HasReceivedAllFrames) return CurrentTime = time; return null; } double frameStart = getFrameTime(currentFrameIndex); double frameEnd = getFrameTime(currentFrameIndex + 1); // If the proposed time is after the current frame end time, we progress forwards to precisely the new frame's time (regardless of incoming time). if (frameEnd <= time) { time = frameEnd; currentFrameIndex++; } // If the proposed time is before the current frame start time, and we are at the frame boundary, we progress backwards. else if (time < frameStart && CurrentTime == frameStart) currentFrameIndex--; frameStart = getFrameTime(currentFrameIndex); frameEnd = getFrameTime(currentFrameIndex + 1); // Pause until more frames are arrived. if (WaitingForFrame && frameStart < time) { CurrentTime = frameStart; return null; } CurrentTime = Math.Clamp(time, frameStart, frameEnd); // In an important section, a mid-frame time cannot be used and a null is returned instead. return inImportantSection && frameStart < time && time < frameEnd ? null : (double?)CurrentTime; } private double getFrameTime(int index) { if (index < 0) return double.NegativeInfinity; if (index >= Frames.Count) return double.PositiveInfinity; return Frames[index].Time; } } }