finished ocr daemon update

tools/OcrDaemon/ScreenCapture.cs

@@ -0,0 +1,65 @@
+namespace OcrDaemon;
+
+using System.Drawing;
+using System.Drawing.Imaging;
+using System.Runtime.InteropServices;
+
+static class ScreenCapture
+{
+    [DllImport("user32.dll")]
+    private static extern bool SetProcessDPIAware();
+
+    [DllImport("user32.dll")]
+    private static extern int GetSystemMetrics(int nIndex);
+
+    public static void InitDpiAwareness() => SetProcessDPIAware();
+
+    /// <summary>
+    /// Capture from screen, or load from file if specified.
+    /// When file is set, loads the image and crops to region.
+    /// </summary>
+    public static Bitmap CaptureOrLoad(string? file, RegionRect? region)
+    {
+        if (!string.IsNullOrEmpty(file))
+        {
+            var fullBmp = new Bitmap(file);
+            if (region != null)
+            {
+                int cx = Math.Max(0, region.X);
+                int cy = Math.Max(0, region.Y);
+                int cw = Math.Min(region.Width, fullBmp.Width - cx);
+                int ch = Math.Min(region.Height, fullBmp.Height - cy);
+                var cropped = fullBmp.Clone(new Rectangle(cx, cy, cw, ch), PixelFormat.Format32bppArgb);
+                fullBmp.Dispose();
+                return cropped;
+            }
+            return fullBmp;
+        }
+        return CaptureScreen(region);
+    }
+
+    public static Bitmap CaptureScreen(RegionRect? region)
+    {
+        int x, y, w, h;
+        if (region != null)
+        {
+            x = region.X;
+            y = region.Y;
+            w = region.Width;
+            h = region.Height;
+        }
+        else
+        {
+            // Primary monitor only (0,0 origin, SM_CXSCREEN / SM_CYSCREEN)
+            x = 0;
+            y = 0;
+            w = GetSystemMetrics(0);   // SM_CXSCREEN
+            h = GetSystemMetrics(1);   // SM_CYSCREEN
+        }
+
+        var bitmap = new Bitmap(w, h, PixelFormat.Format32bppArgb);
+        using var g = Graphics.FromImage(bitmap);
+        g.CopyFromScreen(x, y, 0, 0, new System.Drawing.Size(w, h), CopyPixelOperation.SourceCopy);
+        return bitmap;
+    }
+}