From b582da90e5e9b7f3b80cf5d3c86a0e666bb55a6e Mon Sep 17 00:00:00 2001
From: PopSlime <popslime@qq.com>
Date: Tue, 13 Dec 2022 10:50:34 +0800
Subject: [PATCH] Add optional offset to TimingModel constructor.

---
 Assets/Cryville/Crtr/Extensions/TimingModel.cs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/Assets/Cryville/Crtr/Extensions/TimingModel.cs b/Assets/Cryville/Crtr/Extensions/TimingModel.cs
index acc4a8c..de7332a 100644
--- a/Assets/Cryville/Crtr/Extensions/TimingModel.cs
+++ b/Assets/Cryville/Crtr/Extensions/TimingModel.cs
@@ -1,4 +1,5 @@
 using Cryville.Common.Math;
+using System;
 
 namespace Cryville.Crtr.Extensions {
 	public abstract class TimingModel {
@@ -6,13 +7,16 @@ namespace Cryville.Crtr.Extensions {
 		public double BeatTime { get; protected set; }
 		public BeatTime FractionalBeatTime { get; protected set; }
 		public double BPM { get; set; }
-		public TimingModel() {
+		public TimingModel(double offset) {
+			Time = offset;
 			FractionalBeatTime = new BeatTime(0, 0, 1);
 		}
 	}
 	public class FractionalBeatTimeTimingModel : TimingModel {
+		public FractionalBeatTimeTimingModel(double offset = 0) : base(offset) { }
 		public void ForwardTo(BeatTime t) {
 			if (t == FractionalBeatTime) return;
+			if (BPM == 0) throw new InvalidOperationException("BPM not determined");
 			FractionalBeatTime = t;
 			var nt = t.Decimal;
 			Time += (nt - BeatTime) / BPM * 60;
@@ -20,13 +24,15 @@ namespace Cryville.Crtr.Extensions {
 		}
 	}
 	public class BeatTimeTimingModel : TimingModel {
+		public BeatTimeTimingModel(double offset = 0) : base(offset) { }
 		public void ForwardTo(double t) {
 			if (t == BeatTime) return;
+			if (BPM == 0) throw new InvalidOperationException("BPM not determined");
 			Time += (t - BeatTime) / BPM * 60;
 			BeatTime = t;
 			FractionalBeatTime = ToBeatTime(t);
 		}
-		BeatTime ToBeatTime(double beat, double error = 1e-4) {
+		static BeatTime ToBeatTime(double beat, double error = 1e-4) {
 			int i, n, d;
 			FractionUtils.ToFraction(beat, error, out n, out d);
 			i = n / d; n %= d;