feat(physics): implement Physics2D system (RF4.10)

docs/fase4/README.md

@@ -17,7 +17,7 @@ Esta fase implementa o **ECS completo** — a arquitetura de dados central que c
 | **Event Bus** | [`events.md`](events.md) | `Caffeine::Events` | 4 | ✅ |
 | **Audio System** | [`audio.md`](audio.md) | `Caffeine::Audio` | 4 | 📅 |
 | **Animation System** | [`animation.md`](animation.md) | `Caffeine::Animation` | 4 | 📅 |
-| **Physics 2D** | [`physics.md`](physics.md) | `Caffeine::Physics2D` | 4 | 📅 |
+| **Physics 2D** | [`physics.md`](physics.md) | `Caffeine::Physics2D` | 4 | ✅ |
 | **UI System** | [`ui.md`](ui.md) | `Caffeine::UI` | 4 | 📅 |
 
 ---

docs/fase4/physics.md

@@ -3,7 +3,7 @@
 > **Fase:** 4 — O Cérebro  
 > **Namespace:** `Caffeine::Physics2D`  
 > **Arquivo:** `src/physics/PhysicsSystem2D.hpp`  
-> **Status:** 📅 Planejado  
+> **Status:** ✅ Implementado  
 > **RF:** RF4.10
 
 ---
@@ -16,7 +16,72 @@ Sistema de física 2D simples com suporte a rigid body dynamics, AABB e circle c
 
 ---
 
-## API Planejada
+## API
+
+```cpp
+namespace Caffeine::Physics2D {
+
+struct PhysicsMaterial {
+    f32 friction    = 0.5f;
+    f32 restitution = 0.3f;
+    static PhysicsMaterial ice();
+    static PhysicsMaterial rubber();
+    static PhysicsMaterial metal();
+    static PhysicsMaterial wood();
+    static PhysicsMaterial stone();
+};
+
+struct RigidBody2D {
+    f32  mass          = 1.0f;
+    f32  restitution   = 0.3f;
+    f32  friction      = 0.5f;
+    f32  linearDamping = 0.0f;
+    bool isKinematic   = false;
+    bool lockRotation  = true;
+};
+
+struct Collider2D {
+    Vec2          size      = { 32.0f, 32.0f };
+    Vec2          offset    = { 0.0f, 0.0f };
+    f32           radius    = 16.0f;
+    u32           layer     = 0;
+    u32           layerMask = 0xFFFFFFFF;
+    ColliderShape shape     = ColliderShape::AABB;
+    bool          isStatic  = false;
+    bool          isTrigger = false;
+    bool          isOneWay  = false;
+};
+
+struct Rect2D { Vec2 position; Vec2 size; };
+struct RaycastHit { ECS::Entity entity; Vec2 point; Vec2 normal; f32 distance; bool hit; };
+struct CollisionManifold { Vec2 contactPoint; Vec2 normal; f32 penetration; };
+
+class PhysicsSystem2D : public ECS::ISystem {
+public:
+    explicit PhysicsSystem2D(Events::EventBus* eventBus = nullptr);
+    void onUpdate(ECS::World& world, f32 dt) override;
+
+    void setGravity(Vec2 gravity);
+    Vec2 gravity() const;
+
+    RaycastHit               raycast(ECS::World& world, Vec2 origin, Vec2 dir, f32 maxDist, u32 layerMask = 0xFFFFFFFF);
+    std::vector<ECS::Entity> overlapCircle(ECS::World& world, Vec2 center, f32 radius, u32 layerMask = 0xFFFFFFFF);
+    std::vector<ECS::Entity> overlapAABB(ECS::World& world, Rect2D rect, u32 layerMask = 0xFFFFFFFF);
+
+    void applyForce(ECS::Entity e, Vec2 force);
+    void applyImpulse(ECS::Entity e, Vec2 impulse);
+    void setKinematic(ECS::Entity e, bool kinematic);
+    void teleport(ECS::Entity e, Vec2 position);
+
+    const std::vector<CollisionManifold>& lastManifolds() const;
+};
+
+}
+```
+
+---
+
+## API Planejada (original de referência)
 
 ```cpp
 namespace Caffeine::Physics2D {
@@ -216,8 +281,8 @@ Se o jogo precisar de:
 - [ ] 1K rigid bodies a 60fps
 - [ ] Physics step < 3ms para 1K bodies
 - [ ] `tsan` clean — `applyForce` thread-safe
-- [ ] Raycast retorna hit correto para todos ângulos
-- [ ] Colisões publicam `OnCollision2D` corretamente
+- [x] Raycast retorna hit correto para todos ângulos
+- [x] Colisões publicam `OnCollision2D` corretamente
 
 ---
 

src/Caffeine.hpp

@@ -57,4 +57,8 @@
 // Scene
 #include "scene/SceneComponents.hpp"
 #include "scene/SceneSerializer.hpp"
-#include "scene/SceneManager.hpp"
+#include "scene/SceneManager.hpp"
+
+// Physics
+#include "physics/PhysicsComponents2D.hpp"
+#include "physics/PhysicsSystem2D.hpp"

src/physics/PhysicsComponents2D.hpp

@@ -0,0 +1,46 @@
+#pragma once
+
+#include "core/Types.hpp"
+#include "math/Vec2.hpp"
+
+namespace Caffeine::Physics2D {
+
+using namespace Caffeine;
+
+enum class ColliderShape : u8 { AABB, Circle };
+
+struct PhysicsMaterial {
+    f32 friction    = 0.5f;
+    f32 restitution = 0.3f;
+
+    static PhysicsMaterial ice()    { return { 0.05f, 0.1f }; }
+    static PhysicsMaterial rubber() { return { 0.8f,  0.9f }; }
+    static PhysicsMaterial metal()  { return { 0.6f,  0.3f }; }
+    static PhysicsMaterial wood()   { return { 0.5f,  0.2f }; }
+    static PhysicsMaterial stone()  { return { 0.7f,  0.1f }; }
+};
+
+struct RigidBody2D {
+    f32  mass          = 1.0f;
+    f32  restitution   = 0.3f;
+    f32  friction      = 0.5f;
+    f32  linearDamping = 0.0f;
+    bool isKinematic   = false;
+    bool lockRotation  = true;
+    bool isSleeping    = false;
+    f32  sleepTimer    = 0.0f;
+};
+
+struct Collider2D {
+    Vec2          size      = { 32.0f, 32.0f };
+    Vec2          offset    = { 0.0f,  0.0f  };
+    f32           radius    = 16.0f;
+    u32           layer     = 0;
+    u32           layerMask = 0xFFFFFFFF;
+    ColliderShape shape     = ColliderShape::AABB;
+    bool          isStatic  = false;
+    bool          isTrigger = false;
+    bool          isOneWay  = false;
+};
+
+}