move backend to subfolder

tanks-backend/TanksServer/Graphics/DrawTanksStep.cs

@@ -0,0 +1,56 @@
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.PixelFormats;
+using TanksServer.GameLogic;
+
+namespace TanksServer.Graphics;
+
+internal sealed class DrawTanksStep : IDrawStep
+{
+    private readonly MapEntityManager _entityManager;
+    private readonly bool[] _tankSprite;
+    private readonly int _tankSpriteWidth;
+
+    public DrawTanksStep(MapEntityManager entityManager)
+    {
+        _entityManager = entityManager;
+
+        using var tankImage = Image.Load<Rgba32>("assets/tank.png");
+        _tankSprite = new bool[tankImage.Height * tankImage.Width];
+
+        var whitePixel = new Rgba32(byte.MaxValue, byte.MaxValue, byte.MaxValue, byte.MaxValue);
+        var i = 0;
+        for (var y = 0; y < tankImage.Height; y++)
+        for (var x = 0; x < tankImage.Width; x++, i++)
+            _tankSprite[i] = tankImage[x, y] == whitePixel;
+
+        _tankSpriteWidth = tankImage.Width;
+    }
+
+    public void Draw(GamePixelGrid pixels)
+    {
+        foreach (var tank in _entityManager.Tanks)
+        {
+            var tankPosition = tank.Bounds.TopLeft;
+
+            for (byte dy = 0; dy < MapService.TileSize; dy++)
+            for (byte dx = 0; dx < MapService.TileSize; dx++)
+            {
+                if (!TankSpriteAt(dx, dy, tank.Orientation))
+                    continue;
+
+                var (x, y) = tankPosition.GetPixelRelative(dx, dy);
+                pixels[x, y].EntityType = GamePixelEntityType.Tank;
+                pixels[x, y].BelongsTo = tank.Owner;
+            }
+        }
+    }
+
+    private bool TankSpriteAt(int dx, int dy, int tankRotation)
+    {
+        var x = tankRotation % 4 * (MapService.TileSize + 1);
+        var y = (int)Math.Floor(tankRotation / 4d) * (MapService.TileSize + 1);
+        var index = (y + dy) * _tankSpriteWidth + x + dx;
+
+        return _tankSprite[index];
+    }
+}