Этап 7

Minint.Core/Services/Impl/FloodFillService.cs

@@ -0,0 +1,47 @@
+using Minint.Core.Models;
+
+namespace Minint.Core.Services.Impl;
+
+public sealed class FloodFillService : IFloodFillService
+{
+    public void Fill(MinintLayer layer, int x, int y, int newColorIndex, int width, int height)
+    {
+        if (x < 0 || x >= width || y < 0 || y >= height)
+            return;
+
+        var pixels = layer.Pixels;
+        int targetIndex = pixels[y * width + x];
+
+        if (targetIndex == newColorIndex)
+            return;
+
+        var queue = new Queue<(int X, int Y)>();
+        var visited = new bool[width * height];
+
+        queue.Enqueue((x, y));
+        visited[y * width + x] = true;
+
+        while (queue.Count > 0)
+        {
+            var (cx, cy) = queue.Dequeue();
+            pixels[cy * width + cx] = newColorIndex;
+
+            Span<(int, int)> neighbors =
+            [
+                (cx - 1, cy), (cx + 1, cy),
+                (cx, cy - 1), (cx, cy + 1)
+            ];
+
+            foreach (var (nx, ny) in neighbors)
+            {
+                if (nx < 0 || nx >= width || ny < 0 || ny >= height)
+                    continue;
+                int ni = ny * width + nx;
+                if (visited[ni] || pixels[ni] != targetIndex)
+                    continue;
+                visited[ni] = true;
+                queue.Enqueue((nx, ny));
+            }
+        }
+    }
+}