just_dart 0.1.0

Shared Dart utilities for Just Ecosystem.

Just Dart

just_dart provides small, reusable building blocks used across the Just ecosystem, with a focus on gameplay/runtime math and low-overhead spatial queries.

Features

• Mutable Vector2 for fast 2-D math (addScaled, normalize, dot/cross)
• Mutable Vector3 for 3-D or 2.5-D data (toOffset, cross product, distance)
• Lightweight generic Quadtree<T> for axis-aligned rectangle spatial queries
• Flutter interop helpers (Offset conversions) for rendering pipelines

Getting Started

Environment:

• Dart SDK ^3.11.0

From the package root:

dart pub get

Import the package:

import 'package:just_dart/just_dart.dart';

Usage

Vector2 (mutable 2-D math)

import 'package:just_dart/just_dart.dart';

void main() {
	final velocity = Vector2(3, 4);
	final position = Vector2.zero();

	// Integrate: position += velocity * dt
	const dt = 0.016;
	position.addScaled(velocity, dt);

	final speed = velocity.length; // 5.0
	velocity.normalize();          // mutates velocity to unit length

	print('speed=$speed pos=${position.toOffset()} vel=$velocity');
}

Vector3 (mutable 3-D math)

import 'package:just_dart/just_dart.dart';

void main() {
	final a = Vector3(1, 2, 3);
	final b = Vector3(0, 1, 0);

	final dot = a.dot(b);
	final normal = a.cross(b); // returns a new Vector3

	a.addScaled(Vector3(10, 0, 0), 0.1); // in-place mutation

	// For Flutter Canvas APIs (2-D projection)
	final screenPos = a.toOffset();

	print('dot=$dot normal=$normal screenPos=$screenPos');
}

Quadtree (spatial broad-phase)

import 'package:flutter/painting.dart';
import 'package:just_dart/just_dart.dart';

void main() {
	final tree = Quadtree<String>(
		bounds: const Rect.fromLTWH(-500, -500, 1000, 1000),
		maxItems: 8,
		maxDepth: 6,
	);

	tree.insert('player', const Rect.fromLTWH(10, 20, 24, 24));
	tree.insert('enemy_1', const Rect.fromLTWH(40, 35, 20, 20));

	final nearby = <String>[];
	tree.queryRect(const Rect.fromLTWH(0, 0, 80, 80), nearby);

	print(nearby); // ['player', 'enemy_1']
}

API Surface

• Vector2
• Vector3
• Quadtree<T>

Re-export path:

import 'package:just_dart/just_dart.dart';

Development

From packages/just_dart:

dart pub get
dart test
dart analyze

Contributing

• See CONTRIBUTING.md
• See CODE_OF_CONDUCT.md

License

BSD-3-Clause. See LICENSE.