NodeTree is a framework to create large scalable programs and games through a tree of processes. Each process is fully autonomous and is capable of storing its own state or data, and communicating with other processes. These processes are known as Nodes.
THIS IS A NIGHTLY-DEPENDENT CRATE.
This crate is in early development. Beware of possible bugs or safety violations.
The specific nightly version this crate uses is v1.78.
Simply either run cargo add node_tree
at the terminal directed towards the directory of your project, or add node_tree = X.X
to your cargo.toml
file.
To begin creating a program in Rust that utilizes a NodeTree
, we must first create a root Node
. In order to reduce boilerplate, we will use the included NodeSys
derive macro to implement the required Dynamic
and NodeAbstract
traits. We will then implement the Node
trait ourselves.
#![feature(arbitrary_self_types)] // Required for now.
use node_tree::prelude::*;
#[derive(Debug, Clone, NodeSys)]
pub struct NodeA {
base: Rc<NodeBase> // Required for Nodes.
}
// To make things simple, it is advised to have most node constructors return the node
// instance wrapped inside of this crate's `Hp<T>` pointer.
impl NodeA {
fn new(name: String) -> Hp<Self> {
Hp::new(NodeA { base: NodeBase::new(name) })
}
}
// Example implementation of the Node trait with custom behaviours.
impl Node for NodeA {
/// Runs once the Node is added to the NodeTree.
fn ready(self: Hp<Self>) -> () {
// To show off how you could add children nodes.
if self.depth() < 3 {
self.add_child(NodeA::new(format!("{}_Node", self.depth() + 1)));
self.add_child(NodeA::new(format!("{}_Node", self.depth() + 1)));
self.add_child(NodeA::new(format!("{}_Node", self.depth() + 1)));
}
if self.is_root() {
println!("{:#?}", self.children());
}
}
/// Runs once per frame. Provides a delta value in seconds between frames.
fn process(self: Hp<Self>, delta: f32) -> () {
// Example of using the delta value to calculate the current framerate.
println!("{} | {}", self.name(), 1f32 / delta);
// Using the NodePath, you can reference other nodes in the NodeTree from this node.
if self.is_root() {
match self.get_node(NodePath::from_str("1_Node/2_Node1/3_Node2")) {
Some(node) => println!("{:?}", node),
None => ()
}
}
// Nodes can be destroyed. When destroyed, their references from the NodeTree are cleaned up as well.
// If the root node is destroyed, then the program automatically exits. (There are other ways to
// terminate the program such as the queue_termination() function on the NodeTree instance).
if self.children().is_empty() {
self.free(); // We test the progressive destruction of nodes from the tip of the tree
// to the base.
}
}
/// Runs once a Node is removed from the NodeTree, whether that is from the program itself terminating or not.
fn terminal(self: Hp<Self>) -> () {} // We do not do anything here for this example.
/// Returns this node's process mode.
/// Each process mode controls how the process() function behaves when the NodeTree is paused or not.
/// (The NodeTree can be paused or unpaused with the pause() or unpause() functions respectively.)
fn process_mode(self: Hp<Self>) -> ProcessMode {
ProcessMode::Inherit // We will return the default value, which inherits the behaviour from
// the parent node.
}
}
Finally, in order to activate our NodeTree
, we must instance the root Node
and feed it into the NodeTree
constructor.
// ...previous implementations
fn main() -> () {
// Create the tree.
let root: Hp<NodeA> = NodeA::new("Root".to_string());
let tree: Hp<NodeTree> = NodeTree::new(root);
// Begin operations on the tree.
tree.start();
tree.process(); // This will run an indefinite loop until the program exits.
}
- ๐๏ธ An easy abstraction framework for different processes to communicate and interact with each other in a scalable manner. Inspired by Godot!
- โฏ๏ธ The ability to
pause()
andunpause()
theNodeTree
, and fine tune individualNode
behaviours for when a tree is paused/unpaused. - ๐ก Various methods to communicate with other nodes, such as
owner()
,parent()
,get_child()
,children()
, andget_node()
. - ๐ An abstracted smart pointer known as
Hp<T>
which clones implicitly to reduce syntax noise and allows for low boilerplate. - ๐ช The ability to manage nodes with
add_child()
andremove_child()
. - ๐ฒ Allows for the direct referencing of the
NodeTree
through a node'sroot()
function. - ๐ TODO: A caching system hosted on the
NodeTree
to act as a safe interface to ensure theHp<T>
soundness, and increase performance! - ๐ TODO: Includes a method to save and handle individual node scenes, such as the handy visual macro
Scene!
.