box collider

include/game/agame/player.hpp

@@ -10,6 +10,6 @@ GAME_ENTITY(Player)
         private:
             Object::Sound mSound;
             float mSpeed = 200.f; // Pixels per second
-            float mHealth = 100.f;
+            [[maybe_unused]] float mHealth = 100.f;
 END_GAME_ENTITY()
 }

include/object/components/boxcollider.hpp

@@ -1,8 +1,13 @@
 #pragma once
 
 #include <object/components/component.hpp>
+#include <state/gamestate.hpp>
 
 namespace Game::Object::Components {
+    struct BoxColliderBounds {
+        float left, right, top, bottom;
+    };
+
     class BoxCollider : public Component {
         public:
             BoxCollider() = default;
@@ -15,6 +20,11 @@ namespace Game::Object::Components {
             void start(Object::Entity* thisEntity) override;
             void update(float deltaTime, Object::Entity* thisEntity) override;
 
+            BoxColliderBounds getBounds() const { return mBounds; }
+            bool isColliding() const { return mIsColliding; }
+
         private:
+            BoxColliderBounds mBounds;
+            bool mIsColliding = false; // Whether this collider is currently colliding with another collider; used to determine whether to call onCollisionEnter vs onCollisionStay, and to call onCollisionExit when collisions end
     };
 }

include/object/entity.hpp

@@ -35,6 +35,14 @@ namespace Game::Object {
             virtual void destroyed() {}; // Pre-destruction call
             void render(Game::Renderer::Renderer* renderer, Game::Renderer::RendererConfig config);
 
+            // Collision calls
+            // Called once when a collision begins
+            virtual void onCollisionEnter(Entity* other) {}
+            // Called every update while a collision continues
+            virtual void onCollisionStay(Entity* other) {}
+            // Called once when a collision ends
+            virtual void onCollisionExit(Entity* other) {}
+
             // Setters and getters
             void setTexture(std::shared_ptr<Game::Renderer::Texture> tex) { mTex = tex; }
             void setName(const std::string& name) { mName = name; }

include/state/gamestate.hpp

@@ -26,8 +26,8 @@ namespace Game::State {
 
             // Update entity at index, by REFERENCE.
             Object::Entity* getAtIndex(size_t at);
-            // Add an entity to the gamestate.
+            // Add an entity to the gamestate; Returns a temporary pointer to the entity added. Note that the validity of this pointer cannot be guaranteed after the first call.
-            void addEntity(std::unique_ptr<Object::Entity> entity);
+            Object::Entity* addEntity(std::unique_ptr<Object::Entity> entity);
             bool removeEntity(const std::string& name);
 
         private:

include/utils.hpp

@@ -3,6 +3,7 @@
 #include <iostream>
 #include <SDL3/SDL.h>
 #include <shared_mutex>
+#include <mutex>
 #include <random>
 #include <cstdlib>
 

src/main.cpp

@@ -9,6 +9,7 @@
 #include <renderer/texture.hpp>
 #include <renderer/font.hpp>
 #include <game/agame/sampletextbox.hpp>
+#include <object/components/boxcollider.hpp>
 
 using namespace Game;
 
@@ -22,7 +23,8 @@ int main() {
 
     //Object::Transform t1{100.f, 100.f, 0.f, 1.f, 1.f};
     State::GameState::getInstance().addEntity(std::make_unique<AGame::Background>("BG", std::make_shared<Game::Renderer::Texture>("../resources/bgtest.png", window.getRenderer()->getSDLRenderer()), Object::DEFAULT_TRANSFORM));
-    State::GameState::getInstance().addEntity(std::make_unique<AGame::Player>("Player", std::make_shared<Game::Renderer::Texture>("../resources/l3ladja.png", window.getRenderer()->getSDLRenderer()), Object::DEFAULT_TRANSFORM));
+    Object::Entity* player = State::GameState::getInstance().addEntity(std::make_unique<AGame::Player>("Player", std::make_shared<Game::Renderer::Texture>("../resources/l3ladja.png", window.getRenderer()->getSDLRenderer()), Object::DEFAULT_TRANSFORM));
+    player->addComponent<Object::Components::BoxCollider>();
     //State::GameState::getInstance().addEntity(std::make_unique<AGame::Player>("Player2", std::make_shared<Game::Renderer::Font>("../resources/roboto.ttf", window.getRenderer()->getSDLRenderer(), 128, "Roboto"), t1));
 
     window.run();

src/object/components/boxcollider.cpp

@@ -1,4 +1,5 @@
 #include <object/components/boxcollider.hpp>
+#include <object/entity.hpp>
 
 namespace Game::Object::Components {
     BoxCollider::BoxCollider(const BoxCollider& other) : Component(other) {
@@ -31,5 +32,44 @@ namespace Game::Object::Components {
 
     void BoxCollider::update(float deltaTime, Object::Entity* thisEntity) {
         // Collision detection and response logic can go here
+
+        // Make box bounds
+        Transform* transform = thisEntity->getTransform();
+        float halfWidth = transform->scaleX * UNIVERSAL_SCALE_COEFFICIENT * 0.5f;
+        float halfHeight = transform->scaleY * UNIVERSAL_SCALE_COEFFICIENT * 0.5f;
+        float left = transform->x - halfWidth;
+        float right = transform->x + halfWidth;
+        float top = transform->y - halfHeight;
+        float bottom = transform->y + halfHeight;
+
+        mBounds = {left, right, top, bottom};
+
+        // Check for collisions with other entities that have box colliders
+        // For simplicity, just check each
+        std::vector<Entity*> entities = State::GameState::getInstance().getEntitiesSnapshot();
+        for (Entity* other : entities) {
+            if (other == thisEntity) continue; // Don't check collision with self
+            BoxCollider* otherCollider = other->getComponent<BoxCollider>();
+            if (!otherCollider) continue; // No collider, skip
+            BoxColliderBounds otherBounds = otherCollider->getBounds();
+            if (left < otherBounds.right && right > otherBounds.left && top < otherBounds.bottom && bottom > otherBounds.top) {
+                // Collision detected
+                if (!mIsColliding) {
+                    mIsColliding = true;
+                    thisEntity->onCollisionEnter(other);
+                    other->onCollisionEnter(thisEntity);
+                } else {
+                    thisEntity->onCollisionStay(other);
+                    other->onCollisionStay(thisEntity);
+                }
+            } else {
+                // No collision
+                if (mIsColliding) {
+                    mIsColliding = false;
+                    thisEntity->onCollisionExit(other);
+                    other->onCollisionExit(thisEntity);
+                }
+            }
+        }
     }
 }

src/state/gamestate.cpp

@@ -13,7 +13,7 @@ namespace Game::State {
         }
     }
     
-    void GameState::addEntity(std::unique_ptr<Object::Entity> entity) {
+    Object::Entity* GameState::addEntity(std::unique_ptr<Object::Entity> entity) {
         Object::Entity* addedEntity = nullptr;
         {
             std::lock_guard<std::mutex> lock(mMutex); // Lock the mutex for thread safety
@@ -23,6 +23,7 @@ namespace Game::State {
 
         addedEntity->start(); // Initialize the entity after insertion without holding the GameState lock.
         LOG("Added entity '" << addedEntity->getName() << "' to GameState");
+        return addedEntity;
     }
 
     bool GameState::removeEntity(const std::string& name) {