Initial commit

ecs/component_pool.odin

@@ -0,0 +1,68 @@
+package ecs 
+
+import "core:log"
+
+ComponentPool :: struct($T: typeid) {
+    data: []T,
+    entity_to_index: map[EntityID]uintptr,
+    index_to_entity: map[uintptr]EntityID,
+    size: uintptr,
+}
+
+component_pool_create :: proc($T: typeid) -> ComponentPool(T) {
+    component_pool := ComponentPool(T) {
+        data = make([]T, ENTITY_MAX),
+        entity_to_index = make(map[EntityID]uintptr, context.allocator),
+        index_to_entity = make(map[uintptr]EntityID, context.allocator),
+        size = 0,
+    }
+    
+    return component_pool 
+}
+
+component_pool_insert_data :: proc($T: typeid, component_pool: ^ComponentPool(T), entity_id: EntityID, component: T) {
+    log.assertf(entity_id not_in component_pool.entity_to_index, "Component already added to entity")
+    
+    new_idx := component_pool.size
+    component_pool.entity_to_index[entity_id] = new_idx
+    component_pool.index_to_entity[new_idx] = entity_id
+    component_pool.data[new_idx] = component 
+
+    component_pool.size += 1
+}
+
+component_pool_remove_data :: proc(component_pool: ^ComponentPool(any), entity_id: EntityID) {
+    log.assertf(entity_id in component_pool.entity_to_index, "Entity doesn't have component")
+
+    removed_entity_idx := component_pool.entity_to_index[entity_id]
+    last_element_idx := component_pool.size - 1
+    component_pool.data[removed_entity_idx] = component_pool.data[last_element_idx]
+
+    last_element_entity_id := component_pool.index_to_entity[last_element_idx]
+    component_pool.entity_to_index[last_element_entity_id] = removed_entity_idx
+    component_pool.index_to_entity[removed_entity_idx] = last_element_entity_id
+
+    delete_key(&component_pool.entity_to_index, entity_id)
+    delete_key(&component_pool.index_to_entity, last_element_idx)
+
+    component_pool.size -= 1
+}
+
+component_pool_get :: proc($T: typeid, component_pool: ^ComponentPool(T), entity_id: EntityID) -> ^T {
+    log.assertf(entity_id in component_pool.entity_to_index, "Entity doesn't have component")
+
+    idx := component_pool.entity_to_index[entity_id]
+    return &component_pool.data[idx]
+}
+
+component_pool_destroy_entity :: proc(component_pool: ^ComponentPool(any), entity_id: EntityID) {
+    if entity_id in component_pool.entity_to_index {
+        component_pool_remove_data(component_pool, entity_id)
+    }
+}
+
+component_pool_destroy :: proc(component_pool: ^ComponentPool(any)) {
+    delete(component_pool.entity_to_index)
+    delete(component_pool.index_to_entity)
+    delete(component_pool.data)
+}