From a971ceff2c3e60cd11ba5d8bdb7daa3b8e984f75 Mon Sep 17 00:00:00 2001
From: unclshura <unclshura@gmail.com>
Date: Sat, 19 Sep 2026 10:15:04 +0100
Subject: [PATCH] Fixed camera initial position and gravitate center. Fixed bug
 with reusable buffers.

---
 Splitter-UI/Services/BufferPool.cs           | 64 +++++++-------------
 Splitter-UI/Services/MatToBitmapConverter.cs |  4 +-
 Splitter-UI/Services/ThumbnailService.cs     |  2 +-
 splitter-cli/algo/CameraController.cs        |  5 +-
 4 files changed, 28 insertions(+), 47 deletions(-)

diff --git a/Splitter-UI/Services/BufferPool.cs b/Splitter-UI/Services/BufferPool.cs
index 3f75e71..d8e61a4 100644
--- a/Splitter-UI/Services/BufferPool.cs
+++ b/Splitter-UI/Services/BufferPool.cs
@@ -1,62 +1,42 @@
-namespace Splitter_UI.Services;
+using System.Buffers;
+
+namespace Splitter_UI.Services;
 
 public sealed class BufferPool : IBufferPool
 {
-
-    public sealed class Entry
+    public sealed class Entry : IDisposable
     {
+        private bool _disposed;
+
         public readonly int Width;
         public readonly int Height;
-        public readonly byte[] Bgr;
-        public readonly byte[] Bgra;
 
-        public Entry(int w, int h)
+        public byte[] Bgr;
+        public byte[] Bgra;
+
+        internal Entry(int w, int h)
         {
             Width = w;
             Height = h;
-            Bgr = new byte[w * h * 3];
-            Bgra = new byte[w * h * 4];
+
+            Bgr = ArrayPool<byte>.Shared.Rent(w * h * 3);
+            Bgra = ArrayPool<byte>.Shared.Rent(w * h * 4);
         }
 
-        override public string ToString() => $"Entry({Width}x{Height})";
-    }
+        public void Dispose()
+        {
+            if (_disposed) return;
+            _disposed = true;
 
-    private readonly Dictionary<(int w, int h), LinkedListNode<Entry>> _map;
-    private readonly LinkedList<Entry> _lru;
-    private readonly int _capacity;
-    private readonly Lock _lock = new();
+            ArrayPool<byte>.Shared.Return(Bgr);
+            ArrayPool<byte>.Shared.Return(Bgra);
+        }
 
-    public BufferPool()
-    {
-        _capacity = 8;
-        _map = new Dictionary<(int w, int h), LinkedListNode<Entry>>(_capacity);
-        _lru = new LinkedList<Entry>();
+        public override string ToString() => $"Entry({Width}x{Height})";
     }
 
     public Entry Get(int w, int h)
     {
-        var key = (w, h);
-
-        if (_map.TryGetValue(key, out var node))
-        {
-            _lru.Remove(node);
-            _lru.AddLast(node);
-            return node.Value;
-        }
-
-        var created = new Entry(w, h);
-        var newNode = new LinkedListNode<Entry>(created);
-
-        _lru.AddLast(newNode);
-        _map[key] = newNode;
-
-        if (_lru.Count > _capacity)
-        {
-            var first = _lru.First!;
-            _lru.RemoveFirst();
-            _map.Remove((first.Value.Width, first.Value.Height));
-        }
-
-        return created;
+        return new Entry(w, h);
     }
 }
diff --git a/Splitter-UI/Services/MatToBitmapConverter.cs b/Splitter-UI/Services/MatToBitmapConverter.cs
index 660758b..c651290 100644
--- a/Splitter-UI/Services/MatToBitmapConverter.cs
+++ b/Splitter-UI/Services/MatToBitmapConverter.cs
@@ -22,7 +22,7 @@ public sealed class MatToBitmapConverter(IBufferPool _pool) : IMatToBitmapConver
 
         lock (_sync)
         {
-            var entry = _pool.Get(w, h);
+            using var entry = _pool.Get(w, h);
 
             var src = mat;
             if (!src.IsContinuous())
@@ -65,7 +65,7 @@ public sealed class MatToBitmapConverter(IBufferPool _pool) : IMatToBitmapConver
 
     public Bitmap Convert(byte[] bgr, int width, int height, Bitmap? existing = null)
     {
-        var entry = _pool.Get(width, height);
+        using var entry = _pool.Get(width, height);
         ConvertBgrToBgra(bgr, entry.Bgra, width, height);
 
         if (existing is WriteableBitmap wb &&
diff --git a/Splitter-UI/Services/ThumbnailService.cs b/Splitter-UI/Services/ThumbnailService.cs
index 7ffaa60..7be4014 100644
--- a/Splitter-UI/Services/ThumbnailService.cs
+++ b/Splitter-UI/Services/ThumbnailService.cs
@@ -59,7 +59,7 @@ public sealed class ThumbnailService : IThumbnailService
         height ??= ThumbHeight;
         skip ??= TimeSpan.Zero;
 
-        var entry = _pool.Get(width.Value, height.Value);
+        using var entry = _pool.Get(width.Value, height.Value);
 
         var ok = await DecodeFrameAsync(
             entry.Bgr,
diff --git a/splitter-cli/algo/CameraController.cs b/splitter-cli/algo/CameraController.cs
index 4b92ae2..c874a89 100644
--- a/splitter-cli/algo/CameraController.cs
+++ b/splitter-cli/algo/CameraController.cs
@@ -47,6 +47,7 @@ public sealed class CameraController
         _cropHeight   = cropHeight;
         _kalman       = kalman;
         _cmd          = cmd;
+        DefaultCenter = new Point2f(videoWidth * _cmd.GravitateTo.X, videoHeight * _cmd.GravitateTo.Y);
         _cameraCenter = DefaultCenter;
         _state        = TrackState.Tracking;
 
@@ -58,7 +59,7 @@ public sealed class CameraController
         _kalman.Reset(_cameraCenter);
     }
 
-    private Point2f DefaultCenter => _cmd.GravitateTo;
+    private Point2f DefaultCenter { get; set; }
 
     public int LostFrames         => _lostFrames;
     public Point2f CameraCenter   => _cameraCenter;
@@ -148,7 +149,7 @@ public sealed class CameraController
             smoothedCenter = _kalman.Update(objectCenter);
 
             var driftEasing = 0.01f;
-            var fallbackCenter = new Point2f(_videoWidth / 2f, _videoHeight / 2f);
+            var fallbackCenter = DefaultCenter;
 
             _cameraCenter = new Point2f(
                 _cameraCenter.X + (fallbackCenter.X - _cameraCenter.X) * driftEasing,