Getting shaders working with lua.

src/duskrpg/item/backpack.h

@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#pragma once
+#include "inventory.h"
+
+#define BACKPACK_STORAGE_SIZE_MAX 20
+
+extern inventorystack_t BACKPACK_STORAGE[BACKPACK_STORAGE_SIZE_MAX];
+extern inventory_t BACKPACK;
+
+/**
+ * Initializes the backpack inventory for the player.
+ */
+void backpackInit();