use crate::{serde::SceneSerializer, Scene, SceneSpawnError}; use anyhow::Result; use bevy_ecs::{ entity::EntityMap, reflect::{ReflectComponent, ReflectMapEntities}, world::World, }; use bevy_reflect::{Reflect, TypeRegistryArc, TypeUuid}; use serde::Serialize; /// A collection of serializable dynamic entities, each with its own run-time defined set of components. #[derive(Default, TypeUuid)] #[uuid = "749479b1-fb8c-4ff8-a775-623aa76014f5"] pub struct DynamicScene { pub entities: Vec, } /// A reflection-powered serializable representation of an entity and its components. pub struct DynamicEntity { /// The transiently unique identifier of a corresponding `Entity`. pub entity: u32, /// A vector of boxed components that belong to the given entity and /// implement the `Reflect` trait. pub components: Vec>, } impl DynamicScene { /// Create a new dynamic scene from a given scene. pub fn from_scene(scene: &Scene, type_registry: &TypeRegistryArc) -> Self { Self::from_world(&scene.world, type_registry) } /// Create a new dynamic scene from a given world. pub fn from_world(world: &World, type_registry: &TypeRegistryArc) -> Self { let mut scene = DynamicScene::default(); let type_registry = type_registry.read(); for archetype in world.archetypes().iter() { let entities_offset = scene.entities.len(); // Create a new dynamic entity for each entity of the given archetype // and insert it into the dynamic scene. for entity in archetype.entities() { scene.entities.push(DynamicEntity { entity: entity.id(), components: Vec::new(), }); } // Add each reflection-powered component to the entity it belongs to. for component_id in archetype.components() { let reflect_component = world .components() .get_info(component_id) .and_then(|info| type_registry.get(info.type_id().unwrap())) .and_then(|registration| registration.data::()); if let Some(reflect_component) = reflect_component { for (i, entity) in archetype.entities().iter().enumerate() { if let Some(component) = reflect_component.reflect_component(world, *entity) { scene.entities[entities_offset + i] .components .push(component.clone_value()); } } } } } scene } /// Write the dynamic entities and their corresponding components to the given world. /// /// This method will return a `SceneSpawnError` if either a type is not registered /// or doesn't reflect the `Component` trait. pub fn write_to_world( &self, world: &mut World, entity_map: &mut EntityMap, ) -> Result<(), SceneSpawnError> { let registry = world.resource::().clone(); let type_registry = registry.read(); for scene_entity in &self.entities { // Fetch the entity with the given entity id from the `entity_map` // or spawn a new entity with a transiently unique id if there is // no corresponding entry. let entity = *entity_map .entry(bevy_ecs::entity::Entity::from_raw(scene_entity.entity)) .or_insert_with(|| world.spawn().id()); // Apply/ add each component to the given entity. for component in &scene_entity.components { let registration = type_registry .get_with_name(component.type_name()) .ok_or_else(|| SceneSpawnError::UnregisteredType { type_name: component.type_name().to_string(), })?; let reflect_component = registration.data::().ok_or_else(|| { SceneSpawnError::UnregisteredComponent { type_name: component.type_name().to_string(), } })?; // If the entity already has the given component attached, // just apply the (possibly) new value, otherwise add the // component to the entity. if world .entity(entity) .contains_type_id(registration.type_id()) { reflect_component.apply_component(world, entity, &**component); } else { reflect_component.add_component(world, entity, &**component); } } } for registration in type_registry.iter() { if let Some(map_entities_reflect) = registration.data::() { map_entities_reflect .map_entities(world, entity_map) .unwrap(); } } Ok(()) } // TODO: move to AssetSaver when it is implemented /// Serialize this dynamic scene into rust object notation (ron). pub fn serialize_ron(&self, registry: &TypeRegistryArc) -> Result { serialize_ron(SceneSerializer::new(self, registry)) } } /// Serialize a given Rust data structure into rust object notation (ron). pub fn serialize_ron(serialize: S) -> Result where S: Serialize, { let pretty_config = ron::ser::PrettyConfig::default() .decimal_floats(true) .indentor(" ".to_string()) .new_line("\n".to_string()); let mut buf = Vec::new(); let mut ron_serializer = ron::ser::Serializer::new(&mut buf, Some(pretty_config), false)?; serialize.serialize(&mut ron_serializer)?; Ok(String::from_utf8(buf).unwrap()) }