change InventoryTrait to new trait system

core.mod/src/entities/PlayerEntity.h

@@ -3,12 +3,12 @@
 #include <swan/swan.h>
 #include <array>
 
-class PlayerEntity: public Swan::PhysicsEntity, public Swan::InventoryTrait::HasInventory {
+class PlayerEntity: public Swan::PhysicsEntity, public Swan::InventoryTrait {
 public:
 	PlayerEntity(const Swan::Context &ctx, Swan::Vec2 pos);
 	PlayerEntity(const Swan::Context &ctx, const PackObject &obj);
 
-	Swan::InventoryTrait::Inventory &getInventory() override { return inventory_; }
+	Inventory &get(InventoryTrait::Tag) override { return inventory_; }
 
 	void draw(const Swan::Context &ctx, Swan::Win &win) override;
 	void update(const Swan::Context &ctx, float dt) override;
@@ -24,8 +24,15 @@ private:
 	static constexpr float DOWN_FORCE = 20 * MASS;
 	static constexpr Swan::Vec2 SIZE = Swan::Vec2(0.6, 1.9);
 
+	enum class State {
+		IDLE,
+		RUNNING_L,
+		RUNNING_R,
+		COUNT,
+	};
+
 	PlayerEntity(const Swan::Context &ctx):
-		PhysicsEntity(SIZE), inventory_(INVENTORY_SIZE),
+		PhysicsEntity(SIZE),
 		anims_{
 			Swan::Animation(ctx.resources.getImage("core/entity/player-still"), 0.8),
 			Swan::Animation(
@@ -34,19 +41,11 @@ private:
 			Swan::Animation(ctx.resources.getImage("core/entity/player-running"), 1)
 		} {}
 
-
-	Swan::InventoryTrait::BasicInventory inventory_;
-
-	enum class State {
-		IDLE,
-		RUNNING_L,
-		RUNNING_R,
-		COUNT,
-	};
-
 	State state_ = State::IDLE;
 	std::array<Swan::Animation, (int)State::COUNT> anims_;
 
 	Swan::Clock jump_timer_;
 	Swan::TilePos mouse_tile_;
+
+	BasicInventory inventory_{INVENTORY_SIZE};
 };

libswan/CMakeLists.txt

@@ -1,5 +1,6 @@
 add_library(libswan SHARED
 	src/traits/BodyTrait.cc
+	src/traits/InventoryTrait.cc
 	src/traits/PhysicsTrait.cc
 	src/Animation.cc
 	src/Chunk.cc

libswan/include/swan/traits/InventoryTrait.h

@@ -8,54 +8,32 @@
 
 namespace Swan {
 
-namespace InventoryTrait {
+struct InventoryTrait {
+	struct Inventory;
+	struct Tag {};
+	virtual Inventory &get(Tag) = 0;
 
-class Inventory;
-class HasInventory {
-public:
-	virtual Inventory &getInventory() = 0;
-};
+	struct Inventory {
+		virtual ~Inventory() = default;
 
-class Inventory {
-public:
-	virtual ~Inventory() = default;
+		virtual int size() = 0;
+		virtual ItemStack get(int slot) = 0;
+		virtual ItemStack set(int slot, ItemStack stack) = 0;
+		virtual ItemStack insert(int slot, ItemStack stack) = 0;
 
-	virtual int size() = 0;
-	virtual ItemStack get(int slot) = 0;
-	virtual ItemStack set(int slot, ItemStack stack) = 0;
-	virtual ItemStack insert(int slot, ItemStack stack) = 0;
+		ItemStack insert(ItemStack stack) { return insert(0, stack); }
+	};
 
-	ItemStack insert(ItemStack stack) { return insert(0, stack); }
-};
+	struct BasicInventory: Inventory {
+		BasicInventory(int size): content(size) {}
 
-class BasicInventory: public Inventory {
-public:
-	BasicInventory(int size): size_(size), content_(size) {}
-
-	int size() override { return size_; }
-
-	ItemStack get(int slot) override {
-		if (slot < size_)
-			return content_[slot];
-		return ItemStack();
-	}
-
-	ItemStack set(int slot, ItemStack stack) override {
-		ItemStack st = content_[slot];
-		content_[slot] = stack;
-		return st;
-	}
-
-	ItemStack insert(int slot, ItemStack stack) override {
-		for (int i = 0; !stack.empty() && i < size_; ++i)
-			stack = content_[i].insert(stack);
-		return stack;
-	}
-
-private:
-	int size_;
-	std::vector<ItemStack> content_;
+		std::vector<ItemStack> content;
+
+		int size() override { return content.size(); }
+		ItemStack get(int slot) override;
+		ItemStack set(int slot, ItemStack stack) override;
+		ItemStack insert(int slot, ItemStack stack) override;
+	};
 };
 
 }
-}

libswan/src/traits/InventoryTrait.cc

@@ -0,0 +1,27 @@
+#include "traits/InventoryTrait.h"
+
+namespace Swan {
+
+ItemStack InventoryTrait::BasicInventory::get(int slot) {
+	if (slot >= (ssize_t)content.size())
+		return ItemStack{};
+
+	return content[slot];
+}
+
+ItemStack InventoryTrait::BasicInventory::set(int slot, ItemStack stack) {
+	if (slot >= (ssize_t)content.size())
+		return stack;
+
+	ItemStack st = content[slot];
+	content[slot] = stack;
+	return st;
+}
+
+ItemStack InventoryTrait::BasicInventory::insert(int slot, ItemStack stack) {
+	for (int i = 0; !stack.empty() && i < (ssize_t)content.size(); ++i)
+		stack = content[i].insert(stack);
+	return stack;
+}
+
+}