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osu-lazer/osu.Game/Database/LegacyBeatmapExporter.cs

117 lines
5.1 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.IO;
using System.Linq;
using System.Text;
using osu.Framework.Platform;
using osu.Game.Beatmaps;
using osu.Game.Beatmaps.Formats;
using osu.Game.IO;
using osu.Game.Rulesets.Objects;
using osu.Game.Rulesets.Objects.Types;
using osu.Game.Skinning;
using osuTK;
namespace osu.Game.Database
{
/// <summary>
/// Exporter for osu!stable legacy beatmap archives.
/// Converts all beatmaps in the set to legacy format and exports it as a legacy package.
/// </summary>
public class LegacyBeatmapExporter : LegacyArchiveExporter<BeatmapSetInfo>
{
public LegacyBeatmapExporter(Storage storage)
: base(storage)
{
}
protected override Stream? GetFileContents(BeatmapSetInfo model, INamedFileUsage file)
{
var beatmapInfo = model.Beatmaps.SingleOrDefault(o => o.Hash == file.File.Hash);
if (beatmapInfo == null)
return base.GetFileContents(model, file);
// Read the beatmap contents and skin
using var contentStream = base.GetFileContents(model, file);
if (contentStream == null)
return null;
using var contentStreamReader = new LineBufferedReader(contentStream);
var beatmapContent = new LegacyBeatmapDecoder().Decode(contentStreamReader);
var workingBeatmap = new FlatWorkingBeatmap(beatmapContent);
var playableBeatmap = workingBeatmap.GetPlayableBeatmap(beatmapInfo.Ruleset);
using var skinStream = base.GetFileContents(model, file);
if (skinStream == null)
return null;
using var skinStreamReader = new LineBufferedReader(skinStream);
var beatmapSkin = new LegacySkin(new SkinInfo(), null!)
{
Configuration = new LegacySkinDecoder().Decode(skinStreamReader)
};
// Convert beatmap elements to be compatible with legacy format
// So we truncate time and position values to integers, and convert paths with multiple segments to bezier curves
foreach (var controlPoint in playableBeatmap.ControlPointInfo.AllControlPoints)
controlPoint.Time = Math.Floor(controlPoint.Time);
foreach (var hitObject in playableBeatmap.HitObjects)
{
// Truncate end time before truncating start time because end time is dependent on start time
if (hitObject is IHasDuration hasDuration && hitObject is not IHasPath)
hasDuration.Duration = Math.Floor(hasDuration.EndTime) - Math.Floor(hitObject.StartTime);
hitObject.StartTime = Math.Floor(hitObject.StartTime);
if (hitObject is not IHasPath hasPath) continue;
// stable's hit object parsing expects the entire slider to use only one type of curve,
// and happens to use the last non-empty curve type read for the entire slider.
// this clear of the last control point type handles an edge case
// wherein the last control point of an otherwise-single-segment slider path has a different type than previous,
// which would lead to sliders being mangled when exported back to stable.
// normally, that would be handled by the `BezierConverter.ConvertToModernBezier()` call below,
// which outputs a slider path containing only Bezier control points,
// but a non-inherited last control point is (rightly) not considered to be starting a new segment,
// therefore it would fail to clear the `CountSegments() <= 1` check.
// by clearing explicitly we both fix the issue and avoid unnecessary conversions to Bezier.
if (hasPath.Path.ControlPoints.Count > 1)
hasPath.Path.ControlPoints[^1].Type = null;
if (BezierConverter.CountSegments(hasPath.Path.ControlPoints) <= 1) continue;
var newControlPoints = BezierConverter.ConvertToModernBezier(hasPath.Path.ControlPoints);
// Truncate control points to integer positions
foreach (var pathControlPoint in newControlPoints)
{
pathControlPoint.Position = new Vector2(
(float)Math.Floor(pathControlPoint.Position.X),
(float)Math.Floor(pathControlPoint.Position.Y));
}
hasPath.Path.ControlPoints.Clear();
hasPath.Path.ControlPoints.AddRange(newControlPoints);
}
// Encode to legacy format
var stream = new MemoryStream();
using (var sw = new StreamWriter(stream, Encoding.UTF8, 1024, true))
new LegacyBeatmapEncoder(playableBeatmap, beatmapSkin).Encode(sw);
stream.Seek(0, SeekOrigin.Begin);
return stream;
}
protected override string FileExtension => @".osz";
}
}