Этап 8

Minint.Core/Services/Impl/FragmentService.cs

@@ -0,0 +1,49 @@
+using System;
+using Minint.Core.Models;
+
+namespace Minint.Core.Services.Impl;
+
+public sealed class FragmentService : IFragmentService
+{
+    public void CopyFragment(
+        MinintDocument srcDoc, int srcLayerIndex,
+        int srcX, int srcY, int regionWidth, int regionHeight,
+        MinintDocument dstDoc, int dstLayerIndex,
+        int dstX, int dstY,
+        int containerWidth, int containerHeight)
+    {
+        ArgumentOutOfRangeException.ThrowIfNegative(srcLayerIndex);
+        ArgumentOutOfRangeException.ThrowIfNegative(dstLayerIndex);
+        if (srcLayerIndex >= srcDoc.Layers.Count)
+            throw new ArgumentOutOfRangeException(nameof(srcLayerIndex));
+        if (dstLayerIndex >= dstDoc.Layers.Count)
+            throw new ArgumentOutOfRangeException(nameof(dstLayerIndex));
+
+        var srcLayer = srcDoc.Layers[srcLayerIndex];
+        var dstLayer = dstDoc.Layers[dstLayerIndex];
+
+        int clippedSrcX = Math.Max(srcX, 0);
+        int clippedSrcY = Math.Max(srcY, 0);
+        int clippedEndX = Math.Min(srcX + regionWidth, containerWidth);
+        int clippedEndY = Math.Min(srcY + regionHeight, containerHeight);
+
+        for (int sy = clippedSrcY; sy < clippedEndY; sy++)
+        {
+            int dy = dstY + (sy - srcY);
+            if (dy < 0 || dy >= containerHeight) continue;
+
+            for (int sx = clippedSrcX; sx < clippedEndX; sx++)
+            {
+                int dx = dstX + (sx - srcX);
+                if (dx < 0 || dx >= containerWidth) continue;
+
+                int srcIdx = srcLayer.Pixels[sy * containerWidth + sx];
+                if (srcIdx == 0) continue; // skip transparent
+
+                RgbaColor color = srcDoc.Palette[srcIdx];
+                int dstIdx = dstDoc.EnsureColorCached(color);
+                dstLayer.Pixels[dy * containerWidth + dx] = dstIdx;
+            }
+        }
+    }
+}