fix bullet cannot hit close to tank

README.md

@@ -108,4 +108,3 @@ There are other commands implemented as well, e.g. for changing the brightness.
 ## Backlog: Bugs, Wishes, Ideas
 - Generalize drawing of entities as there are multiple classes with pretty much the same code
 - Generalize hit box collision
-- BUG: when standing next to a wall, the bullet sometimes misses the first pixel

tanks-backend/TanksServer.sln

@@ -10,6 +10,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "shared", "shared", "{12DB7D
 	ProjectSection(SolutionItems) = preProject
 		global.json = global.json
 		shared.props = shared.props
+		Dockerfile = Dockerfile
 	EndProjectSection
 EndProject
 Global

tanks-backend/TanksServer/GameLogic/CollideBullets.cs

@@ -41,7 +41,7 @@ internal sealed class CollideBullets(
 
     private bool BulletHitsTank(Bullet bullet)
     {
-        if (!TryHitTankAt(bullet.Position, bullet.Owner))
+        if (!TryHitTankAt(bullet.Position, bullet.Owner, DateTime.Now > bullet.OwnerCollisionAfter))
             return false;
 
         if (bullet.IsExplosive)
@@ -49,16 +49,20 @@ internal sealed class CollideBullets(
         return true;
     }
 
-    private bool TryHitTankAt(FloatPosition position, Player owner)
+    private bool TryHitTankAt(FloatPosition position, Player owner, bool canHitOwnTank)
     {
         foreach (var tank in entityManager.Tanks)
         {
+            var hitsOwnTank = owner == tank.Owner;
+            if (hitsOwnTank && !canHitOwnTank)
+                continue;
+
             var (topLeft, bottomRight) = tank.Bounds;
             if (position.X < topLeft.X || position.X > bottomRight.X ||
                 position.Y < topLeft.Y || position.Y > bottomRight.Y)
                 continue;
 
-            if (owner != tank.Owner)
+            if (!hitsOwnTank)
                 owner.Scores.Kills++;
             tank.Owner.Scores.Deaths++;
 
@@ -79,7 +83,7 @@ internal sealed class CollideBullets(
             if (options.Value.DestructibleWalls && map.Current.TryDestroyWallAt(offsetPixel))
                 owner.Scores.WallsDestroyed++;
 
-            TryHitTankAt(offsetPixel.ToFloatPosition(), owner);
+            TryHitTankAt(offsetPixel.ToFloatPosition(), owner, true);
         }
     }
 }

tanks-backend/TanksServer/GameLogic/MapEntityManager.cs

@@ -21,7 +21,15 @@ internal sealed class MapEntityManager(
         .Concat(PowerUps);
 
     public void SpawnBullet(Player tankOwner, FloatPosition position, double rotation, bool isExplosive)
-        => _bullets.Add(new Bullet(tankOwner, position, rotation, isExplosive, DateTime.Now + _bulletTimeout));
+        => _bullets.Add(new Bullet
+        {
+            Owner = tankOwner,
+            Position = position,
+            Rotation = rotation,
+            IsExplosive = isExplosive,
+            Timeout = DateTime.Now + _bulletTimeout,
+            OwnerCollisionAfter = DateTime.Now + TimeSpan.FromSeconds(1),
+        });
 
     public void RemoveBulletsWhere(Predicate<Bullet> predicate) => _bullets.RemoveWhere(predicate);
 

tanks-backend/TanksServer/GameLogic/ShootFromTanks.cs

@@ -26,33 +26,10 @@ internal sealed class ShootFromTanks(
 
         tank.NextShotAfter = DateTime.Now.AddMilliseconds(_config.ShootDelayMs);
 
-        var rotation = tank.Orientation / 16d;
-        var angle = rotation * 2d * Math.PI;
-
-        /* When standing next to a wall, the bullet sometimes misses the first pixel.
-         Spawning the bullet to close to the tank instead means the tank instantly hits itself.
-         Because the tank has a float position, but hit boxes are based on pixels, this problem has been deemed complex
-         enough to do later. These values mostly work. */
-        var distance = (tank.Orientation % 4) switch
-        {
-            0 => 4.4d,
-            1 or 3 => 5.4d,
-            2 => 6d,
-            _ => throw new UnreachableException("this should not be possible")
-        };
-
-        var position = new FloatPosition(
-            tank.Position.X + Math.Sin(angle) * distance,
-            tank.Position.Y - Math.Cos(angle) * distance
-        );
-
-        var explosive = false;
-        if (tank.ExplosiveBullets > 0)
-        {
+        var explosive = tank.ExplosiveBullets > 0;
+        if (explosive)
             tank.ExplosiveBullets--;
-            explosive = true;
-        }
 
-        entityManager.SpawnBullet(tank.Owner, position, rotation, explosive);
+        entityManager.SpawnBullet(tank.Owner, tank.Position, tank.Orientation / 16d, explosive);
     }
 }

tanks-backend/TanksServer/Models/Bullet.cs

@@ -1,16 +1,18 @@
 namespace TanksServer.Models;
 
-internal sealed class Bullet(Player tankOwner, FloatPosition position, double rotation, bool isExplosive, DateTime timeout) : IMapEntity
+internal sealed class Bullet : IMapEntity
 {
-    public Player Owner { get; } = tankOwner;
+    public required Player Owner { get; init; }
 
-    public double Rotation { get; } = rotation;
+    public required double Rotation { get; init; }
 
-    public FloatPosition Position { get; set; } = position;
+    public required FloatPosition Position { get; set; }
 
-    public bool IsExplosive { get; } = isExplosive;
+    public required bool IsExplosive { get; init; }
 
-    public DateTime Timeout { get; } = timeout;
+    public required DateTime Timeout { get; init; }
 
-    public PixelBounds Bounds => new (Position.ToPixelPosition(), Position.ToPixelPosition());
+    public PixelBounds Bounds => new(Position.ToPixelPosition(), Position.ToPixelPosition());
+
+    internal required DateTime OwnerCollisionAfter { get; init; }
 }