[WIP] SimaiGenerator初步

Author: Starrah

Program.cs

@@ -16,11 +16,6 @@ private static int Main(string[] args)
         {
             return root.Parse(args).Invoke();
         }
-        catch (NotImplementedException ex)
-        {
-            Console.Error.WriteLine(ex.Message);
-            return 1;
-        }
         catch (ConversionException ex)
         {
             PrintAlerts(ex.Alerts, "转换失败：");

chart/BPMList.cs

@@ -38,6 +38,12 @@ public int FindIndex(Rational time)
         return i-1;
     }
 
+    public bool IsBpmChanged(Rational start, Rational end)
+    {
+        var bpmIdx = FindIndex(start);
+        return bpmIdx < Count - 1 && this[bpmIdx + 1].Time < end;
+    }
+
     private string DebuggerDisplay()
     {
         var result = "";

generator/SimaiGenerator.cs

@@ -0,0 +1,171 @@
+using System.Numerics;
+using System.Text;
+using MuConvert.chart;
+using MuConvert.utils;
+using Rationals;
+using static MuConvert.utils.Alert.LEVEL;
+
+namespace MuConvert.generator;
+
+class SimaiNote
+{
+    public Rational Time;
+    public string Note;
+    public bool IsBpm;
+
+    public SimaiNote(Rational time, string note, bool isBpm = false)
+    {
+        Time = time;
+        Note = note;
+        IsBpm = isBpm;
+    }
+};
+
+public class SimaiGenerator : IGenerator
+{
+    private readonly List<Alert> alerts = [];
+    private StringBuilder result = new StringBuilder();
+#pragma warning disable CS8618
+    private Chart chart;
+#pragma warning restore CS8618
+    
+    private List<SimaiNote> buf = [];
+    private int bpmIdx = 0; // 当前遍历到了哪个bpm
+    
+    private BigInteger bufBarWholepart = 0; // 以下两个用于控制分小节写入
+    private bool lastWriteEmpty = false;
+    private Dictionary<Slide, SimaiNote> sharedHeadBuf = new(); // 以下两个用于控制星星头的缓存，确保同头星星可以直接被连接到正确的simai语句上
+    private Rational sharedHeadBufTime = 0;
+
+    private void flush()
+    {
+        throw new NotImplementedException();
+    }
+
+    private string DurationStr(Note note)
+    {
+        var ib = note.Duration.InvariantBar;
+        // 当发生以下两种情况之一时，返回bar格式原值；否则返回秒
+        // 1. duration全程bpm没有变化
+        // 2. 算出来的InvariantBar，分母小于等于16分音
+        if (ib.Denominator <= 16 || !chart.BpmList.IsBpmChanged(note.Time, note.Time + ib))
+        {
+            return $"[{ib.Denominator}:{ib.Numerator}]";
+        }
+        else
+        { // 返回绝对时间
+            return $"[#{(decimal)note.Duration.Seconds:0.###}]";
+        }
+    }
+    
+    public (string, List<Alert>) Generate(Chart _chart)
+    {
+        if (chart != null) throw new Exception(Locale.InstanceMultipleUsage);
+        chart = _chart;
+
+        int noteIdx = 0;
+        while (noteIdx < chart.Notes.Count)
+        {
+            var note = chart.Notes[noteIdx];
+            var time = note.Time;
+            
+            // 先看是否引发bpm change，如果是的话，则本次循环只结算这个bpm change
+            BPM? bpmChange = null;
+            if (bpmIdx < chart.BpmList.Count && time >= chart.BpmList[bpmIdx].Time)
+            {
+                bpmChange = chart.BpmList[bpmIdx];
+                time = chart.BpmList[bpmIdx].Time;
+            }
+            
+            // 基于时间的缓存清理
+            while (time.WholePart > bufBarWholepart)
+            { // 如果进入了新的小节，则写入上一小节缓存下来的数据
+                flush();
+                bufBarWholepart++;
+            }
+            if (time != sharedHeadBufTime)
+            { // 清空sharedHeadBuf
+                sharedHeadBuf.Clear();
+                sharedHeadBufTime = time;
+            }
+            
+            if (bpmChange != null)
+            { // 本次循环只结算这个bpm change
+                buf.Add(new SimaiNote(bpmChange.Time, $"({bpmChange.Bpm})", true));
+                continue;
+            }
+
+            string res;
+            if (note is Hold hold)
+            {
+                res = $"{hold.Key}h{hold.Modifiers}{DurationStr(hold)}";
+            }
+            else if (note is Tap tap)
+            {
+                var starModifier = tap is Star ? "$" : "";
+                res = $"{tap.Key}{starModifier}{tap.Modifiers}";
+            }
+            else if (note is TouchHold th)
+            {
+                res = $"{th.TouchArea}h{th.Modifiers}{DurationStr(th)}";
+            }
+            else if (note is Touch touch)
+            {
+                res = $"{touch.TouchArea}{touch.Modifiers}";
+            }
+            else if (note is Slide slide)
+            {
+                // 处理头
+                if (slide.SharedHeadWith != null) res = "*";
+                else if (slide.OwnHead != null)
+                {
+                    var starModifier = slide.OwnHead is not Star ? "@" : "";
+                    res = $"{slide.Key}{starModifier}{slide.OwnHead.Modifiers}";
+                }
+                else res = $"{slide.Key}?";
+
+                bool durationOccured = false;
+                foreach (var seg in slide.segments)
+                {
+                    res += seg.Type.ToSimai(seg.StartKey);
+                    res += seg.EndKey;
+                    
+                    if (seg.Duration != null)
+                    {
+                        durationOccured = true;
+                    }
+                    else if (durationOccured)
+                    { // 如果此前有某段出现过时间，说明是分段时间的写法。但我自己却没有时间，说明是非法的写法
+                        alerts.Add(new Alert(Error, Locale.InvalidSlide, (chart, time), null, res));
+                        throw new ConversionException(alerts);
+                    }
+                }
+
+                if (slide.SharedHeadWith != null)
+                {
+                    if (!sharedHeadBuf.TryGetValue(slide.SharedHeadWithRoot, out var src))
+                    { // 没找到前一段星星对应的字符串
+                        alerts.Add(new Alert(Error, Locale.MA2CNSlideNoPrevious, (chart, time), null, res));
+                        throw new ConversionException(alerts);
+                    }
+                    Utils.Assert(src.Time == time);
+                    src.Note += res;
+                    res = "";
+                }
+                else
+                {
+                    var simaiNote = new SimaiNote(time, res);
+                    buf.Add(simaiNote);
+                    res = ""; // 我自己加进simaiNote里去，循环外面的公共逻辑就不要加了
+                    sharedHeadBuf[slide] = simaiNote;
+                }
+            }
+            else throw Utils.Fail("SimaiGenerator遇到了未知的Note对象");
+
+            if (!string.IsNullOrEmpty(res)) buf.Add(new SimaiNote(time, res));
+            noteIdx++;
+        }
+
+        return ("", alerts);
+    }
+}