Struct bevy::ecs::component::ComponentDescriptor
source · pub struct ComponentDescriptor { /* private fields */ }
Expand description
A value describing a component or resource, which may or may not correspond to a Rust type.
Implementations§
source§impl ComponentDescriptor
impl ComponentDescriptor
sourcepub fn new<T>() -> ComponentDescriptorwhere
T: Component,
pub fn new<T>() -> ComponentDescriptorwhere
T: Component,
Create a new ComponentDescriptor
for the type T
.
sourcepub unsafe fn new_with_layout(
name: impl Into<Cow<'static, str>>,
storage_type: StorageType,
layout: Layout,
drop: Option<for<'a> unsafe fn(_: OwningPtr<'a>)>
) -> ComponentDescriptor
pub unsafe fn new_with_layout( name: impl Into<Cow<'static, str>>, storage_type: StorageType, layout: Layout, drop: Option<for<'a> unsafe fn(_: OwningPtr<'a>)> ) -> ComponentDescriptor
Create a new ComponentDescriptor
.
§Safety
- the
drop
fn must be usable on a pointer with a value of the layoutlayout
- the component type must be safe to access from any thread (Send + Sync in rust terms)
Examples found in repository?
examples/ecs/dynamic.rs (lines 87-92)
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fn main() {
let mut world = World::new();
let mut lines = std::io::stdin().lines();
let mut component_names = HashMap::<String, ComponentId>::new();
let mut component_info = HashMap::<ComponentId, ComponentInfo>::new();
println!("{}", PROMPT);
loop {
print!("\n> ");
let _ = std::io::stdout().flush();
let Some(Ok(line)) = lines.next() else {
return;
};
if line.is_empty() {
return;
};
let Some((first, rest)) = line.trim().split_once(|c: char| c.is_whitespace()) else {
match &line.chars().next() {
Some('c') => println!("{}", COMPONENT_PROMPT),
Some('s') => println!("{}", ENTITY_PROMPT),
Some('q') => println!("{}", QUERY_PROMPT),
_ => println!("{}", PROMPT),
}
continue;
};
match &first[0..1] {
"c" => {
rest.split(',').for_each(|component| {
let mut component = component.split_whitespace();
let Some(name) = component.next() else {
return;
};
let size = match component.next().map(|s| s.parse::<usize>()) {
Some(Ok(size)) => size,
_ => 0,
};
// Register our new component to the world with a layout specified by it's size
// SAFETY: [u64] is Send + Sync
let id = world.init_component_with_descriptor(unsafe {
ComponentDescriptor::new_with_layout(
name.to_string(),
StorageType::Table,
Layout::array::<u64>(size).unwrap(),
None,
)
});
let Some(info) = world.components().get_info(id) else {
return;
};
component_names.insert(name.to_string(), id);
component_info.insert(id, info.clone());
println!("Component {} created with id: {:?}", name, id.index());
});
}
"s" => {
let mut to_insert_ids = Vec::new();
let mut to_insert_data = Vec::new();
rest.split(',').for_each(|component| {
let mut component = component.split_whitespace();
let Some(name) = component.next() else {
return;
};
// Get the id for the component with the given name
let Some(&id) = component_names.get(name) else {
println!("Component {} does not exist", name);
return;
};
// Calculate the length for the array based on the layout created for this component id
let info = world.components().get_info(id).unwrap();
let len = info.layout().size() / std::mem::size_of::<u64>();
let mut values: Vec<u64> = component
.take(len)
.filter_map(|value| value.parse::<u64>().ok())
.collect();
values.resize(len, 0);
// Collect the id and array to be inserted onto our entity
to_insert_ids.push(id);
to_insert_data.push(values);
});
let mut entity = world.spawn_empty();
// Construct an `OwningPtr` for each component in `to_insert_data`
let to_insert_ptr = to_owning_ptrs(&mut to_insert_data);
// SAFETY:
// - Component ids have been taken from the same world
// - Each array is created to the layout specified in the world
unsafe {
entity.insert_by_ids(&to_insert_ids, to_insert_ptr.into_iter());
}
println!("Entity spawned with id: {:?}", entity.id());
}
"q" => {
let mut builder = QueryBuilder::<FilteredEntityMut>::new(&mut world);
parse_query(rest, &mut builder, &component_names);
let mut query = builder.build();
query.iter_mut(&mut world).for_each(|filtered_entity| {
let terms = filtered_entity
.components()
.map(|id| {
let ptr = filtered_entity.get_by_id(id).unwrap();
let info = component_info.get(&id).unwrap();
let len = info.layout().size() / std::mem::size_of::<u64>();
// SAFETY:
// - All components are created with layout [u64]
// - len is calculated from the component descriptor
let data = unsafe {
std::slice::from_raw_parts_mut(
ptr.assert_unique().as_ptr().cast::<u64>(),
len,
)
};
// If we have write access, increment each value once
if filtered_entity.access().has_write(id) {
data.iter_mut().for_each(|data| {
*data += 1;
});
}
format!("{}: {:?}", info.name(), data[0..len].to_vec())
})
.collect::<Vec<_>>()
.join(", ");
println!("{:?}: {}", filtered_entity.id(), terms);
});
}
_ => continue,
}
}
}
sourcepub fn new_resource<T>() -> ComponentDescriptorwhere
T: Resource,
pub fn new_resource<T>() -> ComponentDescriptorwhere
T: Resource,
Create a new ComponentDescriptor
for a resource.
The StorageType
for resources is always TableStorage
.
sourcepub fn storage_type(&self) -> StorageType
pub fn storage_type(&self) -> StorageType
Returns a value indicating the storage strategy for the current component.
Trait Implementations§
source§impl Clone for ComponentDescriptor
impl Clone for ComponentDescriptor
source§fn clone(&self) -> ComponentDescriptor
fn clone(&self) -> ComponentDescriptor
Returns a copy of the value. Read more
1.0.0 · source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from
source
. Read moreAuto Trait Implementations§
impl Freeze for ComponentDescriptor
impl RefUnwindSafe for ComponentDescriptor
impl Send for ComponentDescriptor
impl Sync for ComponentDescriptor
impl Unpin for ComponentDescriptor
impl UnwindSafe for ComponentDescriptor
Blanket Implementations§
source§impl<T, U> AsBindGroupShaderType<U> for T
impl<T, U> AsBindGroupShaderType<U> for T
source§fn as_bind_group_shader_type(&self, _images: &RenderAssets<Image>) -> U
fn as_bind_group_shader_type(&self, _images: &RenderAssets<Image>) -> U
Return the
T
ShaderType
for self
. When used in AsBindGroup
derives, it is safe to assume that all images in self
exist.source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
source§impl<T> Downcast for Twhere
T: Any,
impl<T> Downcast for Twhere
T: Any,
source§fn into_any(self: Box<T>) -> Box<dyn Any>
fn into_any(self: Box<T>) -> Box<dyn Any>
Convert
Box<dyn Trait>
(where Trait: Downcast
) to Box<dyn Any>
. Box<dyn Any>
can
then be further downcast
into Box<ConcreteType>
where ConcreteType
implements Trait
.source§fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>
Convert
Rc<Trait>
(where Trait: Downcast
) to Rc<Any>
. Rc<Any>
can then be
further downcast
into Rc<ConcreteType>
where ConcreteType
implements Trait
.source§fn as_any(&self) -> &(dyn Any + 'static)
fn as_any(&self) -> &(dyn Any + 'static)
Convert
&Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &Any
’s vtable from &Trait
’s.source§fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
fn as_any_mut(&mut self) -> &mut (dyn Any + 'static)
Convert
&mut Trait
(where Trait: Downcast
) to &Any
. This is needed since Rust cannot
generate &mut Any
’s vtable from &mut Trait
’s.