Changed X11 capture to only use a single fullscreen texture

Author: DarthAffe

ScreenCapture.NET.X11/X11ScreenCapture.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using ScreenCapture.NET.Downscale;
@@ -18,8 +17,11 @@ public sealed class X11ScreenCapture : AbstractScreenCapture<ColorBGRA>
     private readonly object _captureLock = new();
 
     private nint _display;
-
-    private readonly Dictionary<CaptureZone<ColorBGRA>, ZoneTextures> _textures = new();
+    private nint _drawable;
+    private nint _imageHandle;
+    private X11.XImage _image;
+    private int _size;
+    private unsafe ReadOnlySpan<byte> Data => new(_image.data, _size);
 
     #endregion
 
@@ -43,53 +45,44 @@ protected override bool PerformScreenCapture()
     {
         lock (_captureLock)
         {
-            if (_display == 0)
+            if ((_display == 0) || (_imageHandle == 0))
             {
                 Restart();
                 return false;
             }
 
-            lock (CaptureZones)
-                lock (_textures)
-                    foreach (CaptureZone<ColorBGRA> captureZone in CaptureZones)
-                    {
-                        if (!_textures.TryGetValue(captureZone, out ZoneTextures? textures)) break;
-                        textures.Update();
-                    }
+            X11.XGetSubImage(_display, _drawable, 0, 0, (uint)Display.Width, (uint)Display.Height, X11.ALL_PLANES, X11.ZPIXMAP, _imageHandle, 0, 0);
 
             return true;
         }
     }
 
     protected override void PerformCaptureZoneUpdate(CaptureZone<ColorBGRA> captureZone, in Span<byte> buffer)
     {
-        lock (_textures)
+        using IDisposable @lock = captureZone.Lock();
         {
-            using IDisposable @lock = captureZone.Lock();
-            {
-                if (captureZone.DownscaleLevel == 0)
-                    CopyZone(captureZone, buffer);
-                else
-                    DownscaleZone(captureZone, buffer);
-            }
+            if (captureZone.DownscaleLevel == 0)
+                CopyZone(captureZone, buffer);
+            else
+                DownscaleZone(captureZone, buffer);
         }
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private void CopyZone(CaptureZone<ColorBGRA> captureZone, in Span<byte> buffer)
     {
-        if (!_textures.TryGetValue(captureZone, out ZoneTextures? textures)) return;
-
-        ReadOnlySpan<ColorBGRA> source = MemoryMarshal.Cast<byte, ColorBGRA>(textures.Data);
+        ReadOnlySpan<ColorBGRA> source = MemoryMarshal.Cast<byte, ColorBGRA>(Data);
         Span<ColorBGRA> target = MemoryMarshal.Cast<byte, ColorBGRA>(buffer);
 
+        int offsetX = captureZone.X;
+        int offsetY = captureZone.Y;
         int width = captureZone.Width;
         int height = captureZone.Height;
-        int sourceStride = textures.Image.bytes_per_line / ColorBGRA.ColorFormat.BytesPerPixel;
+        int sourceStride = _image.bytes_per_line / captureZone.ColorFormat.BytesPerPixel;
 
         for (int y = 0; y < height; y++)
         {
-            int sourceOffset = y * sourceStride;
+            int sourceOffset = ((y + offsetY) * sourceStride) + offsetX;
             int targetOffset = y * width;
             source.Slice(sourceOffset, width).CopyTo(target.Slice(targetOffset, width));
         }
@@ -98,9 +91,7 @@ private void CopyZone(CaptureZone<ColorBGRA> captureZone, in Span<byte> buffer)
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private void DownscaleZone(CaptureZone<ColorBGRA> captureZone, in Span<byte> buffer)
     {
-        if (!_textures.TryGetValue(captureZone, out ZoneTextures? textures)) return;
-
-        ReadOnlySpan<byte> source = textures.Data;
+        ReadOnlySpan<byte> source = Data;
         Span<byte> target = buffer;
 
         int blockSize = captureZone.DownscaleLevel switch
@@ -116,17 +107,19 @@ private void DownscaleZone(CaptureZone<ColorBGRA> captureZone, in Span<byte> buf
             _ => (int)Math.Pow(2, captureZone.DownscaleLevel),
         };
 
+        int offsetX = captureZone.X;
+        int offsetY = captureZone.Y;
         int width = captureZone.Width;
         int height = captureZone.Height;
         int stride = captureZone.Stride;
         int bpp = captureZone.ColorFormat.BytesPerPixel;
-        int sourceStride = textures.Image.bytes_per_line / ColorBGRA.ColorFormat.BytesPerPixel;
+        int sourceStride = _image.bytes_per_line / bpp;
 
         Span<byte> scaleBuffer = stackalloc byte[bpp];
         for (int y = 0; y < height; y++)
             for (int x = 0; x < width; x++)
             {
-                AverageByteSampler.Sample(new SamplerInfo<byte>(x * blockSize, y * blockSize, blockSize, blockSize, sourceStride, bpp, source), scaleBuffer);
+                AverageByteSampler.Sample(new SamplerInfo<byte>((x + offsetX) * blockSize, (y + offsetY) * blockSize, blockSize, blockSize, sourceStride, bpp, source), scaleBuffer);
 
                 int targetOffset = (y * stride) + (x * bpp);
 
@@ -138,57 +131,6 @@ private void DownscaleZone(CaptureZone<ColorBGRA> captureZone, in Span<byte> buf
             }
     }
 
-    /// <inheritdoc />
-    public override CaptureZone<ColorBGRA> RegisterCaptureZone(int x, int y, int width, int height, int downscaleLevel = 0)
-    {
-        CaptureZone<ColorBGRA> captureZone = base.RegisterCaptureZone(x, y, width, height, downscaleLevel);
-
-        lock (_textures)
-            InitializeCaptureZone(captureZone);
-
-        return captureZone;
-    }
-
-    /// <inheritdoc />
-    public override bool UnregisterCaptureZone(CaptureZone<ColorBGRA> captureZone)
-    {
-        if (!base.UnregisterCaptureZone(captureZone)) return false;
-
-        lock (_textures)
-        {
-            if (_textures.TryGetValue(captureZone, out ZoneTextures? textures))
-            {
-                textures.Dispose();
-                _textures.Remove(captureZone);
-
-                return true;
-            }
-
-            return false;
-        }
-    }
-
-    /// <inheritdoc />
-    public override void UpdateCaptureZone(CaptureZone<ColorBGRA> captureZone, int? x = null, int? y = null, int? width = null, int? height = null, int? downscaleLevel = null)
-    {
-        base.UpdateCaptureZone(captureZone, x, y, width, height, downscaleLevel);
-
-        if ((width != null) || (height != null))
-        {
-            lock (_textures)
-            {
-                if (_textures.TryGetValue(captureZone, out ZoneTextures? textures))
-                {
-                    textures.Dispose();
-                    InitializeCaptureZone(captureZone);
-                }
-            }
-        }
-    }
-
-    private void InitializeCaptureZone(in CaptureZone<ColorBGRA> captureZone)
-        => _textures[captureZone] = new ZoneTextures(_display, captureZone.Display.Index, captureZone.X, captureZone.Y, captureZone.UnscaledWidth, captureZone.UnscaledHeight);
-
     /// <inheritdoc />
     public override void Restart()
     {
@@ -200,6 +142,14 @@ public override void Restart()
             try
             {
                 _display = X11.XOpenDisplay(X11.DISPLAY_NAME);
+
+                nint screen = X11.XScreenOfDisplay(_display, Display.Index);
+                _drawable = X11.XRootWindowOfScreen(screen);
+                _imageHandle = X11.XGetImage(_display, _drawable, 0, 0, (uint)Display.Width, (uint)Display.Height, X11.ALL_PLANES, X11.ZPIXMAP);
+                _image = Marshal.PtrToStructure<X11.XImage>(_imageHandle);
+                _size = _image.bytes_per_line * _image.height;
+
+                if (_image.bits_per_pixel != (ColorBGRA.ColorFormat.BytesPerPixel * 8)) throw new NotSupportedException("The X-Server is configured to a not supported pixel-format. Needs to be 32 bit per pixel BGR.");
             }
             catch
             {
@@ -214,87 +164,21 @@ protected override void Dispose(bool disposing)
 
         lock (_captureLock)
         {
-            try
-            {
-                foreach ((CaptureZone<ColorBGRA> _, ZoneTextures textures) in _textures)
-                    textures.Dispose();
-
-                DisposeDisplay();
-            }
+            try { DisposeDisplay(); }
             catch { /**/ }
         }
     }
 
     private void DisposeDisplay()
     {
-        if (_display == 0) return;
+        if (_imageHandle != 0)
+            try { X11.XDestroyImage(_imageHandle); } catch { /**/ }
+
+        _image = default;
 
-        try { X11.XCloseDisplay(_display); } catch { /**/ }
+        if (_display != 0)
+            try { X11.XCloseDisplay(_display); } catch { /**/ }
     }
 
     #endregion
-
-    private sealed class ZoneTextures : IDisposable
-    {
-        #region Properties & Fields
-
-        private readonly int _screenNumber;
-        private readonly int _x;
-        private readonly int _y;
-        private readonly uint _width;
-        private readonly uint _height;
-        private readonly int _size;
-
-        private nint _display;
-        private nint _drawable;
-        public nint ImageHandle { get; private set; }
-        public X11.XImage Image { get; private set; }
-        public unsafe ReadOnlySpan<byte> Data => new(Image.data, _size);
-
-        #endregion
-
-        #region Constructors
-
-        public ZoneTextures(nint display, int screenNumber, int x, int y, int width, int height)
-        {
-            this._screenNumber = screenNumber;
-            this._x = x;
-            this._y = y;
-            this._width = (uint)width;
-            this._height = (uint)height;
-
-            _size = width * height * ColorBGRA.ColorFormat.BytesPerPixel;
-            Initialize(display);
-        }
-
-        #endregion
-
-        #region Methods
-
-        public void Initialize(nint display)
-        {
-            Dispose();
-
-            _display = display;
-
-            nint screen = X11.XScreenOfDisplay(_display, _screenNumber);
-            _drawable = X11.XRootWindowOfScreen(screen);
-            ImageHandle = X11.XGetImage(display, _drawable, _x, _y, _width, _height, X11.ALL_PLANES, X11.ZPIXMAP);
-            Image = Marshal.PtrToStructure<X11.XImage>(ImageHandle);
-
-            if (Image.bits_per_pixel != (ColorBGRA.ColorFormat.BytesPerPixel * 8)) throw new NotSupportedException("The X-Server is configured to a not supported pixel-format. Needs to be 32 bit per pixel BGR.");
-        }
-
-        public void Update() => X11.XGetSubImage(_display, _drawable, _x, _y, _width, _height, X11.ALL_PLANES, X11.ZPIXMAP, ImageHandle, 0, 0);
-
-        public void Dispose()
-        {
-            if (ImageHandle != 0)
-                try { X11.XDestroyImage(ImageHandle); } catch { /**/ }
-
-            Image = default;
-        }
-
-        #endregion
-    }
 }