From 02341ecc4a20b714f04cb15e0c838317462a8686 Mon Sep 17 00:00:00 2001
From: Zhe Fang <founchoo@outlook.com>
Date: Sat, 25 Oct 2025 16:59:03 -0400
Subject: [PATCH] feature: add angle config for fan lyrics effect

---
 .../Controls/LyricsSettingsControl.xaml       | 20 +++++++++++++++--
 .../Helper/VectorHelper.cs                    | 22 +++++++++++++++++++
 .../Models/Settings/LyricsEffectSettings.cs   |  4 +++-
 .../LyricsRendererViewModel.Draw.cs           |  3 ++-
 .../LyricsRendererViewModel.Messages.cs       |  4 ++++
 .../LyricsRendererViewModel.Update.cs         |  2 +-
 LICENSE.txt                                   |  2 +-
 7 files changed, 51 insertions(+), 6 deletions(-)
 create mode 100644 BetterLyrics.WinUI3/BetterLyrics.WinUI3/Helper/VectorHelper.cs

diff --git a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Controls/LyricsSettingsControl.xaml b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Controls/LyricsSettingsControl.xaml
index 8c53e2b..0d6a9df 100644
--- a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Controls/LyricsSettingsControl.xaml
+++ b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Controls/LyricsSettingsControl.xaml
@@ -358,9 +358,25 @@
                     </controls:SettingsExpander>
 
                     <!--  扇形歌词  -->
-                    <controls:SettingsCard x:Uid="SettingsPageFan" HeaderIcon="{ui:FontIcon FontFamily={StaticResource IconFontFamily}, Glyph=&#xEBC5;}">
+                    <controls:SettingsExpander
+                        x:Uid="SettingsPageFan"
+                        HeaderIcon="{ui:FontIcon FontFamily={StaticResource IconFontFamily},
+                                                 Glyph=&#xEBC5;}"
+                        IsExpanded="{x:Bind LyricsEffectSettings.IsFanLyricsEnabled, Mode=OneWay}">
                         <ToggleSwitch IsOn="{x:Bind LyricsEffectSettings.IsFanLyricsEnabled, Mode=TwoWay}" />
-                    </controls:SettingsCard>
+                        <controls:SettingsExpander.Items>
+                            <controls:SettingsCard IsEnabled="{x:Bind LyricsEffectSettings.IsFanLyricsEnabled, Mode=OneWay}">
+                                <local:ExtendedSlider
+                                    Default="30"
+                                    Frequency="1"
+                                    Maximum="90"
+                                    Minimum="-90"
+                                    Unit="°"
+                                    Value="{x:Bind LyricsEffectSettings.FanLyricsAngle, Mode=TwoWay}" />
+
+                            </controls:SettingsCard>
+                        </controls:SettingsExpander.Items>
+                    </controls:SettingsExpander>
 
                     <!--  滚动动画  -->
                     <controls:SettingsExpander
diff --git a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Helper/VectorHelper.cs b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Helper/VectorHelper.cs
new file mode 100644
index 0000000..1d44eba
--- /dev/null
+++ b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Helper/VectorHelper.cs
@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Numerics;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace BetterLyrics.WinUI3.Helper
+{
+    public static class VectorHelper
+    {
+        public static Vector2 WithX(this Vector2 source, float x)
+        {
+            return new Vector2(x, source.Y);
+        }
+
+        public static Vector2 WithY(this Vector2 source, float y)
+        {
+            return new Vector2(source.X, y);
+        }
+    }
+}
diff --git a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Models/Settings/LyricsEffectSettings.cs b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Models/Settings/LyricsEffectSettings.cs
index 9713dc2..1707841 100644
--- a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Models/Settings/LyricsEffectSettings.cs
+++ b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Models/Settings/LyricsEffectSettings.cs
@@ -39,6 +39,7 @@ namespace BetterLyrics.WinUI3.Models.Settings
 
         [ObservableProperty][NotifyPropertyChangedRecipients] public partial int LyricsVerticalEdgeOpacity { get; set; } = 0; // 0% opacity
         [ObservableProperty][NotifyPropertyChangedRecipients] public partial bool IsFanLyricsEnabled { get; set; } = false;
+        [ObservableProperty][NotifyPropertyChangedRecipients] public partial int FanLyricsAngle { get; set; } = 30;
 
         public LyricsEffectSettings(int lyricsScrollTopDuration, int lyricsScrollDuration, int lyricsScrollBottomDuration, EasingType lyricsScrollEasingType)
         {
@@ -68,7 +69,8 @@ namespace BetterLyrics.WinUI3.Models.Settings
                 LyricsScrollTopDelay = this.LyricsScrollTopDelay,
                 LyricsScrollBottomDelay = this.LyricsScrollBottomDelay,
                 LyricsVerticalEdgeOpacity = this.LyricsVerticalEdgeOpacity,
-                IsFanLyricsEnabled = this.IsFanLyricsEnabled
+                IsFanLyricsEnabled = this.IsFanLyricsEnabled,
+                FanLyricsAngle = this.FanLyricsAngle,
             };
         }
     }
diff --git a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Draw.cs b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Draw.cs
index 3cf02af..9150b51 100644
--- a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Draw.cs
+++ b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Draw.cs
@@ -321,7 +321,8 @@ namespace BetterLyrics.WinUI3.ViewModels.LyricsRendererViewModel
                 // 组合变换：缩放 -> 旋转 -> 平移
                 ds.Transform =
                     Matrix3x2.CreateScale((float)line.ScaleTransition.Value, line.CenterPosition)
-                    * Matrix3x2.CreateRotation((float)line.AngleTransition.Value, currentPlayingLine.Position)
+                    * Matrix3x2.CreateRotation((float)line.AngleTransition.Value, 
+                    currentPlayingLine.Position.WithX(_liveStatesService.LiveStates.LyricsWindowStatus.LyricsEffectSettings.FanLyricsAngle < 0 ? (float)_maxLyricsWidth : 0))
                     * Matrix3x2.CreateTranslation((float)_lyricsXTransition.Value, (float)yOffset);
 
                 using var combined = new CanvasCommandList(control);
diff --git a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Messages.cs b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Messages.cs
index d794cf9..eda1946 100644
--- a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Messages.cs
+++ b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Messages.cs
@@ -207,6 +207,10 @@ namespace BetterLyrics.WinUI3.ViewModels.LyricsRendererViewModel
                 {
                     _isLayoutChanged = true;
                 }
+                else if (message.PropertyName == nameof(LyricsEffectSettings.FanLyricsAngle))
+                {
+                    _isLayoutChanged = true;
+                }
             }
             else if (message.Sender is LyricsStyleSettings)
             {
diff --git a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Update.cs b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Update.cs
index 702a875..00980b6 100644
--- a/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Update.cs
+++ b/BetterLyrics.WinUI3/BetterLyrics.WinUI3/ViewModels/LyricsRendererViewModel/LyricsRendererViewModel.Update.cs
@@ -696,7 +696,7 @@ namespace BetterLyrics.WinUI3.ViewModels.LyricsRendererViewModel
 
                     line.AngleTransition.StartTransition(_liveStatesService.LiveStates.LyricsWindowStatus.LyricsEffectSettings.IsFanLyricsEnabled
                             ? Math.PI
-                                * (30.0 / 180.0)
+                                * (_liveStatesService.LiveStates.LyricsWindowStatus.LyricsEffectSettings.FanLyricsAngle / 180.0)
                                 * distanceFactor
                                 * (i > _playingLineIndex ? 1 : -1)
                             : 0
diff --git a/LICENSE.txt b/LICENSE.txt
index ed1214f..fe33cba 100644
--- a/LICENSE.txt
+++ b/LICENSE.txt
@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2025 Zhe Fang
+Copyright (c) 2025 Zhe Fang and contributors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal