3 files changed, 38 insertions, 0 deletions

diff --git a/src/crepe/api/Rigidbody.h b/src/crepe/api/Rigidbody.h
index 756cc28..5c9f6df 100644
--- a/src/crepe/api/Rigidbody.h
+++ b/src/crepe/api/Rigidbody.h
@@ -130,6 +130,16 @@ public:
 		* 
 		*/
 		vec2 offset;
+
+		/**
+		 * \brief Defines the collision layers of a GameObject.
+		 *
+		 * The `collision_layers` vector specifies the layers that the GameObject will collide with.
+		 * Each element in the vector represents a layer ID, and the GameObject will only detect 
+		 * collisions with other GameObjects that belong to these layers.
+		 */
+		std::vector<int> collision_layers;
+
 	};
 
 public:
diff --git a/src/crepe/system/CollisionSystem.cpp b/src/crepe/system/CollisionSystem.cpp
index 34cd125..3c103e9 100644
--- a/src/crepe/system/CollisionSystem.cpp
+++ b/src/crepe/system/CollisionSystem.cpp
@@ -359,6 +359,7 @@ CollisionSystem::gather_collisions(std::vector<CollisionInternal> & colliders) {
 	for (size_t i = 0; i < colliders.size(); ++i) {
 		for (size_t j = i + 1; j < colliders.size(); ++j) {
 			if (colliders[i].id == colliders[j].id) continue;
+			if(!have_common_layer(colliders[i].rigidbody.data.collision_layers,colliders[j].rigidbody.data.collision_layers)) continue;
 			CollisionInternalType type
 				= get_collider_type(colliders[i].collider, colliders[j].collider);
 			if (!get_collision(
@@ -381,6 +382,17 @@ CollisionSystem::gather_collisions(std::vector<CollisionInternal> & colliders) {
 	return collisions_ret;
 }
 
+bool CollisionSystem::have_common_layer(const std::vector<int>& layers1, const std::vector<int>& layers2) {
+    // Iterate through each layer in the first vector
+    for (int layer : layers1) {
+        // Check if the current layer is present in the second vector
+        if (std::find(layers2.begin(), layers2.end(), layer) != layers2.end()) {
+            return true; // Common layer found
+        }
+    }
+    return false; // No common layers found
+}
+
 CollisionSystem::CollisionInternalType
 CollisionSystem::get_collider_type(const collider_variant & collider1,
 								   const collider_variant & collider2) const {
diff --git a/src/crepe/system/CollisionSystem.h b/src/crepe/system/CollisionSystem.h
index 6b5a4bb..a22baf2 100644
--- a/src/crepe/system/CollisionSystem.h
+++ b/src/crepe/system/CollisionSystem.h
@@ -215,6 +215,22 @@ private:
 	gather_collisions(std::vector<CollisionInternal> & colliders);
 
 	/**
+	 * \brief Checks if two collision layers have at least one common layer.
+	 * 
+	 * This function checks if there is any overlapping layer between the two input 
+	 * collision layer vectors. It compares each layer from the first vector to see 
+	 * if it exists in the second vector. If at least one common layer is found, 
+	 * the function returns true, indicating that the two colliders share a common 
+	 * collision layer.
+	 * 
+	 * \param layers1 A vector of collision layers for the first collider.
+	 * \param layers2 A vector of collision layers for the second collider.
+	 * \return Returns true if there is at least one common layer, false otherwise.
+	 */
+
+	bool have_common_layer(const std::vector<int>& layers1, const std::vector<int>& layers2);
+
+	/**
 		* \brief Checks for collision between two colliders.
 		* 
 		* Calls the appropriate collision detection function based on the collider types.