added hotbar selection

Mine2d/engine/EventService.cs

@@ -38,6 +38,10 @@ public class EventService
             {
                 EventPublisher.Publish(EventType.KeyUp, e);
             }
+            if (e.type == SDL_EventType.SDL_MOUSEWHEEL)
+            {
+                EventPublisher.Publish(EventType.MouseWheel, e);
+            }
         }
     }
 }

Mine2d/engine/system/EventType.cs

@@ -9,4 +9,5 @@ public enum EventType
     KeyDown,
     KeyUp,
     WindowResize,
+    MouseWheel,
 }

Mine2d/game/frontend/events/InventoryInput.cs

@@ -0,0 +1,41 @@
+using Mine2d.engine.system;
+using Mine2d.engine.system.annotations;
+
+namespace Mine2d.game.frontend.events;
+
+public class InventoryInput
+{
+    [EventListener(EventType.KeyDown)]
+    public static void OnKeyDown(SDL_Event e)
+    {
+        var frontendGameState = Context.Get().FrontendGameState;
+        frontendGameState.HotbarIndex = e.key.keysym.sym switch
+        {
+            SDL_Keycode.SDLK_1 => 0,
+            SDL_Keycode.SDLK_2 => 1,
+            SDL_Keycode.SDLK_3 => 2,
+            SDL_Keycode.SDLK_4 => 3,
+            SDL_Keycode.SDLK_5 => 4,
+            SDL_Keycode.SDLK_6 => 5,
+            SDL_Keycode.SDLK_7 => 6,
+            SDL_Keycode.SDLK_8 => 7,
+            SDL_Keycode.SDLK_9 => 8,
+            _ => frontendGameState.HotbarIndex
+        };
+    }
+
+    [EventListener(EventType.MouseWheel)]
+    public static void OnMouseWheel(SDL_Event e)
+    {
+        var frontendGameState = Context.Get().FrontendGameState;
+        frontendGameState.HotbarIndex -= e.wheel.y;
+        if (frontendGameState.HotbarIndex < 0)
+        {
+            frontendGameState.HotbarIndex = 8;
+        }
+        if (frontendGameState.HotbarIndex > 8)
+        {
+            frontendGameState.HotbarIndex = 0;
+        }
+    }
+}

Mine2d/game/frontend/renderer/HudRenderer.cs

@@ -7,6 +7,7 @@ namespace Mine2d.game.frontend.renderer;
 public class HudRenderer : IRenderer
 {
     private readonly IntPtr hotbarTexture;
+    private readonly IntPtr hotbarActiveTexture;
 
     public HudRenderer()
     {
@@ -19,17 +20,24 @@ public class HudRenderer : IRenderer
         var surface = IMG_Load_RW(sdlBuffer, 1);
         this.hotbarTexture = Context.Get().Renderer.CreateTextureFromSurface(surface);
         SDL_FreeSurface(surface);
+        (ptr, size) = rl.LoadToIntPtr("assets.hud.hotbar-active.png");
+        sdlBuffer = SDL_RWFromMem(ptr, size);
+        surface = IMG_Load_RW(sdlBuffer, 1);
+        this.hotbarActiveTexture = Context.Get().Renderer.CreateTextureFromSurface(surface);
+        SDL_FreeSurface(surface);
     }
 
     public void Render()
     {
         var renderer = Context.Get().Renderer;
         var uiScale = Context.Get().FrontendGameState.Settings.UiScale;
+        var activeSlot = Context.Get().FrontendGameState.HotbarIndex;
         // var window = Context.Get().Window;
         // var (width, height) = window.GetSize();
         var (hotbarWidth, hotbarHeight) = renderer.GetTextureSize(this.hotbarTexture);
         var player = PlayerEntity.GetSelf();
         renderer.DrawTexture(this.hotbarTexture, 0, 0, hotbarWidth * uiScale, hotbarHeight * uiScale);
+        renderer.DrawTexture(this.hotbarActiveTexture, activeSlot * 24 * uiScale, 0, 24 * uiScale, 24 * uiScale);
         for (var i = 0; i < player?.Inventory.Hotbar.Length; i++)
         {
             var stack = player.Inventory.Hotbar[i];
@@ -40,7 +48,7 @@ public class HudRenderer : IRenderer
 
             var texture = stack.GetTexture();
             renderer.DrawTexture(texture, (4 + i * 20) * uiScale, 4 * uiScale, 16 * uiScale, 16 * uiScale);
-            renderer.DrawText(stack.Count.ToString(), (4 + i * 20) * uiScale, 20 * uiScale);
+            renderer.DrawText("" + stack.Count, (4 + i * 20) * uiScale, 20 * uiScale);
         }
     }
 }

Mine2d/game/state/GameState.cs

@@ -14,6 +14,7 @@ public class FrontendGameState
     public Vector2 MousePosition { get; set; }
     public Settings Settings { get; set; } = new Settings();
     public string PlayerName { get; set; } = "Player";
+    public int HotbarIndex { get; set; }
 }
 
 public class Settings