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osu-lazer/osu.Game/Screens/Edit/EditorClock.cs
2020-01-09 13:43:44 +09:00

132 lines
5.6 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.Linq;
using osu.Framework.Utils;
using osu.Framework.Timing;
using osu.Game.Beatmaps;
using osu.Game.Beatmaps.ControlPoints;
namespace osu.Game.Screens.Edit
{
/// <summary>
/// A decoupled clock which adds editor-specific functionality, such as snapping to a user-defined beat divisor.
/// </summary>
public class EditorClock : DecoupleableInterpolatingFramedClock
{
public readonly double TrackLength;
public ControlPointInfo ControlPointInfo;
private readonly BindableBeatDivisor beatDivisor;
public EditorClock(WorkingBeatmap beatmap, BindableBeatDivisor beatDivisor)
{
this.beatDivisor = beatDivisor;
ControlPointInfo = beatmap.Beatmap.ControlPointInfo;
TrackLength = beatmap.Track.Length;
}
public EditorClock(ControlPointInfo controlPointInfo, double trackLength, BindableBeatDivisor beatDivisor)
{
this.beatDivisor = beatDivisor;
ControlPointInfo = controlPointInfo;
TrackLength = trackLength;
}
/// <summary>
/// Seek to the closest snappable beat from a time.
/// </summary>
/// <param name="position">The raw position which should be seeked around.</param>
/// <returns>Whether the seek could be performed.</returns>
public bool SeekSnapped(double position)
{
var timingPoint = ControlPointInfo.TimingPointAt(position);
double beatSnapLength = timingPoint.BeatLength / beatDivisor.Value;
// We will be snapping to beats within the timing point
position -= timingPoint.Time;
// Determine the index from the current timing point of the closest beat to position
int closestBeat = (int)Math.Round(position / beatSnapLength);
position = timingPoint.Time + closestBeat * beatSnapLength;
// Depending on beatSnapLength, we may snap to a beat that is beyond timingPoint's end time, but we want to instead snap to
// the next timing point's start time
var nextTimingPoint = ControlPointInfo.TimingPoints.FirstOrDefault(t => t.Time > timingPoint.Time);
if (position > nextTimingPoint?.Time)
position = nextTimingPoint.Time;
return Seek(position);
}
/// <summary>
/// Seeks backwards by one beat length.
/// </summary>
/// <param name="snapped">Whether to snap to the closest beat after seeking.</param>
/// <param name="amount">The relative amount (magnitude) which should be seeked.</param>
public void SeekBackward(bool snapped = false, double amount = 1) => seek(-1, snapped, amount);
/// <summary>
/// Seeks forwards by one beat length.
/// </summary>
/// <param name="snapped">Whether to snap to the closest beat after seeking.</param>
/// <param name="amount">The relative amount (magnitude) which should be seeked.</param>
public void SeekForward(bool snapped = false, double amount = 1) => seek(1, snapped, amount);
private void seek(int direction, bool snapped, double amount = 1)
{
if (amount <= 0) throw new ArgumentException("Value should be greater than zero", nameof(amount));
var timingPoint = ControlPointInfo.TimingPointAt(CurrentTime);
if (direction < 0 && timingPoint.Time == CurrentTime)
// When going backwards and we're at the boundary of two timing points, we compute the seek distance with the timing point which we are seeking into
timingPoint = ControlPointInfo.TimingPointAt(CurrentTime - 1);
double seekAmount = timingPoint.BeatLength / beatDivisor.Value * amount;
double seekTime = CurrentTime + seekAmount * direction;
if (!snapped || ControlPointInfo.TimingPoints.Count == 0)
{
Seek(seekTime);
return;
}
// We will be snapping to beats within timingPoint
seekTime -= timingPoint.Time;
// Determine the index from timingPoint of the closest beat to seekTime, accounting for scrolling direction
int closestBeat;
if (direction > 0)
closestBeat = (int)Math.Floor(seekTime / seekAmount);
else
closestBeat = (int)Math.Ceiling(seekTime / seekAmount);
seekTime = timingPoint.Time + closestBeat * seekAmount;
// Due to the rounding above, we may end up on the current beat. This will effectively cause 0 seeking to happen, but we don't want this.
// Instead, we'll go to the next beat in the direction when this is the case
if (Precision.AlmostEquals(CurrentTime, seekTime))
{
closestBeat += direction > 0 ? 1 : -1;
seekTime = timingPoint.Time + closestBeat * seekAmount;
}
if (seekTime < timingPoint.Time && timingPoint != ControlPointInfo.TimingPoints.First())
seekTime = timingPoint.Time;
var nextTimingPoint = ControlPointInfo.TimingPoints.FirstOrDefault(t => t.Time > timingPoint.Time);
if (seekTime > nextTimingPoint?.Time)
seekTime = nextTimingPoint.Time;
// Ensure the sought point is within the boundaries
seekTime = Math.Clamp(seekTime, 0, TrackLength);
Seek(seekTime);
}
}
}