Lib.rs

Hexing

"Hexagons are the bestagons"
A basic Rust library to manipulate hexagonal grids.

hexing is a Rust library designed for manipulation and calculations on hexagonal grids. It provides tools for working with hexagonal positions and directions, as well as iterators for exploring hexagonal rings and spirals.

Features

• Hexagonal Coordinate Manipulation: Represent and manipulate positions in a hexagonal grid using axial coordinates.
• Distance Calculations: Compute the distance between two hexagonal positions.
• Pixel Coordinate Conversion: Convert hexagonal positions to pixel coordinates for graphical use.
• Reflection and Rotation: Apply reflection and rotation to hexagonal positions.
• Ring and Spiral Iterators: Obtain positions in a ring or spiral around a central position.
• Bounding: Calculate if a point is within a hexagonal bounding box.
• Line Iterators: Obtain positions along a line between two hexagonal positions.
• Number Trait: Allow generic calculations with various numeric types.
• Serialization and Deserialization: Serialize and deserialize hexagonal positions and directions with the serde feature.
• Pathfinding: Find the shortest path between two hexagonal positions using the A* algorithm.
• Field of view: Calculate the field of view of a hexagonal grid.
• Field of movements: Calculate the movement field of a hexagonal grid.
• Noise generation: Generate noise maps for hexagonal grids using the noise crate.

The Serde feature documentation is located in the docs/serde.md file. And documentation for the pathfinding, field of view, field of movement and noise generation features are located in the docs/layout.md file.

Number Trait

The library uses the Number trait to allow generic calculations with various numeric types. This trait is implemented for several types, including integers and floating-point numbers.

Main Types

HexPosition<T>

Represents a position in a hexagonal grid with coordinates T. Coordinates are in axial format (x, y).

• Creation: Creates a new [HexPosition] with the given q and r coordinates in an axial format. Coordinates are explained in this documentation.

  let pos = HexPosition::new(1, 2);
  let pos2 = HexPosition(3, 4);
  
  // Constant: The origin of the hexagonal grid.
  let origin = HexPosition::ORIGIN;
  

• Conversion to Pixel Coordinates: Converts the current [HexPosition] into a pixel coordinate. Basically, it converts a position in a hexagonal grid to a position in a orthogonal grid.

  let pixel_coords = pos.to_pixel_coordinates();
  let pixel_coords2 = HexPosition::from_pixel_coordinates(pixel_coords);
  

• Distance Calculation: Calculates the distance between two hexagonal positions, using the Manhattan distance.

  let distance = pos.distance(HexPosition::new(3, 4));
  

• Rotation: Will apply a rotation of 2 x 60 degrees around the origin.

  let rotated_pos = pos.rotation(2);
  

• Reflection: Will apply a central symmetric reflection around the origin.

  let reflected_pos = pos.reflect();
  

• Ring Iterators: A iterator that returns positions in a ring around a central position. The iterator will return positions in a ring with the given radius.

  for ring_pos in pos.ring(2) {
      println!("{:?}", ring_pos);
  }
  

• Spiral Iterators: A iterator that returns positions in a spiral around a central position. The iterator will return positions in a spiral with the given radius.

  for spiral_pos in pos.spiral(2) {
      println!("{:?}", spiral_pos);
  }
  

• Line Iterators A iterator that returns positions along a line between two hexagonal positions.

  let a = HexPosition(0, 0);
  let b = HexPosition(-2, -1);
  for line_pos in a.line(b) {
      println!("{:?}", line_pos);
  }
  

• Bounding: A utility function that calculates the bounding box of a hexagonal grid.

  use hexing::{utils::HexBound, HexPosition};
  
  let center = HexPosition(0, 0);
  let radius = 3;
  
  let bounding_box = HexBound::new(center, radius);
  
  assert!(bounding_box.contains(HexPosition(0, 0)));
  assert_eq!(bounding_box.radius(), 3);
  assert_eq!(bounding_box.center(), HexPosition(0, 0));
  

HexDirection

Enum representing the six possible directions in a hexagonal grid.

• Available Directions:

  • Right (1, 0)
  • UpRight (1, -1)
  • UpLeft (0, -1)
  • Left (-1, 0)
  • DownLeft (-1, 1)
  • DownRight (0, 1)

• Convert to Vector: You can convert a [HexDirection] to a [HexPosition] by using the to_vector method.

  let direction = HexDirection::Right;
  let vector = direction.to_vector();
  

Usage Examples

Here are some examples to illustrate the features of hexing.

Creating Hexagonal Positions

use hexing::HexPosition;

let pos = HexPosition::new(1, 2);
let pos2 = HexPosition(3, 4);
let origin = HexPosition::ORIGIN;

println!("Position 1: {:?}", pos);
println!("Position 2: {:?}", pos2);
println!("Origin: {:?}", origin);

Conversion to Pixel Coordinates

use hexing::HexPosition;

let position = HexPosition::new(1, 0);
let pixel_coords = position.to_pixel_coordinates();
println!("Pixel coordinates: {:?}", pixel_coords);

let new_position: HexPosition<i32> = HexPosition::from_pixel_coordinates(pixel_coords);
println!("New position: {:?}", new_position);

assert!(position == new_position);

Calculating Distance Between Positions

use hexing::HexPosition;

let pos1 = HexPosition::new(0, 0);
let pos2 = HexPosition::new(-2, -1);
let dist = pos1.distance(pos2);
println!("Distance: {:?}", dist);

Iterating Over Rings and Spirals

use hexing::{HexPosition, HexRing, HexSpiral};

let center = HexPosition::new(0, 0);

// Ring of radius 1
let ring = center.ring(1);
for pos in ring {
    println!("Ring position: {:?}", pos);
}

// Spiral of radius 2
let spiral = center.spiral(2);
for pos in spiral {
    println!("Spiral position: {:?}", pos);
}

Rotation of Hexagonal Position

use hexing::HexPosition;
let rotation = 120;
let pos = HexPosition::new(1, 2);
let rotated_pos = pos.rotation(rotation/60); // Rotates 120 degrees
println!("Rotated Position: {:?}", rotated_pos);

Reflection of Hexagonal Position

use hexing::HexPosition;

let pos = HexPosition::new(1, 2);
let reflected_pos = pos.reflect();
println!("Reflected Position: {:?}", reflected_pos);

Line Iterator

use hexing::HexPosition;

let start = HexPosition::new(0, 0);
let end = HexPosition::new(3, -3);
for pos in start.line(end) {
    println!("Line Position: {:?}", pos);
}

Using HexDirection

use hexing::HexDirection;

let direction = HexDirection::UpRight;
let vector = direction.to_vector();
println!("Vector for Right Direction: {:?}", vector);

let new_position = HexPosition::new(0, 0) + vector * 3;
println!("New Position after moving Right: {:?}", new_position);

Full Documentation

For more detailed documentation and additional explanations about hexagonal grids, please refer to the Red Blob Games hexagonal grid documentation.

Installation

Add hexing to your Cargo.toml:

[dependencies]
hexing = "0.3.3"