Initial commit

ecs/entity_manager.odin

@@ -0,0 +1,54 @@
+package ecs 
+
+import "core:log"
+import "core:container/queue"
+
+EntityManager :: struct {
+    available_entities: queue.Queue(EntityID),
+    signatures: [ENTITY_MAX]Signature,
+    living_entity_count: u32,
+}
+
+entity_manager_create :: proc() -> EntityManager {
+    entity_manager := EntityManager{living_entity_count = 0}
+    queue.init(&entity_manager.available_entities)
+
+    for entity_id in 0..<ENTITY_MAX {
+        queue.push_back(&entity_manager.available_entities, cast(EntityID)entity_id)
+    }
+
+    return entity_manager
+}
+
+entity_manager_create_entity :: proc(entity_manager: ^EntityManager) -> EntityID {
+    log.assertf(entity_manager.living_entity_count < ENTITY_MAX, "Too many entities created")
+
+    entity_id := queue.pop_front(&entity_manager.available_entities)
+    entity_manager.living_entity_count += 1
+    
+    return entity_id
+}
+
+entity_manager_destroy_entity :: proc(entity_manager: ^EntityManager, entity_id: EntityID) {
+    log.assertf(entity_id < ENTITY_MAX, "Entity ID out of range")
+
+    signature_clear(&entity_manager.signatures[entity_id])
+    queue.push_back(&entity_manager.available_entities, entity_id)
+    entity_manager.living_entity_count -= 1
+}
+
+entity_manager_set_signature :: proc(entity_manager: ^EntityManager, entity_id: EntityID, signature: Signature) {
+    log.assertf(entity_id < ENTITY_MAX, "Entity ID out of range")
+
+    entity_manager.signatures[entity_id] = signature
+}
+
+entity_manager_get_signature :: proc(entity_manager: ^EntityManager, entity_id: EntityID) -> Signature {
+    log.assertf(entity_id < ENTITY_MAX, "Entity ID out of range")
+
+    return entity_manager.signatures[entity_id]
+}
+
+entity_manager_destroy :: proc(entity_manager: ^EntityManager) {
+    queue.destroy(&entity_manager.available_entities)
+}