Godot Grid Engine

A Godot library for games with grid-based movement.

Uses Godot 4 and C#.

Library Design

This library provides three public types: Grid, Board, and BoardLayer.

Grid is a static, data-only Resource type which contains the basic representation of a 2D grid. It is loaded by the other types.

Board is a Node2D container type which serves as a wrapper around a Dictionary data structure to hold one or more BoardLayer values. Using multiple layers allows for the organization of differing types, such as separating movable units from items on the ground.

BoardLayer is another Node2D type which contains logic for interacting with occupants, cell highlighting, and pathfinding. At its core, BoardLayer is a wrapper around a Dictionary data structure containing values which implement the IOccupant interface, allowing you to provide your own types when adding content to a layer. IOccupant is a minimal interface to ensure BoardLayer occupants can be moved between grid cells. The interface contains the following methods:

public interface IOccupant
{
  // GetCell should return the Occupant's current position. This is used when
  // moving Occupants, or when pathfinding for an Occupant.
  Vector2I GetCell();

  // GetRange determines how far the Occupant can move by restricting pathfinding.
  int GetRange();

  // ReadyToMove provides an opportunity to prevent an Occupant's movement.
  bool ReadyToMove();
}

Usage

In order to get started, do the following:

1. Create a Grid resource based on the definition in Resources/Grid.cs.
2. Instantiate a Board with one or more BoardLayer children.
3. Implement an occupant type using the IOccupant interface.

Once this is done, you can start adding units to the board, and connect Input signals to perform actions. See the BoardLayer interface for details.

There is an end-to-end example in the Example/ directory. Specifically, see Example.cs and the accompanying scene. To reproduce this in the editor, you will need to create tilesets for each tilemap. Be sure to add a terrain layer and bitmask to the PathTiles tileset.

To Do

• Integrate with Godot 4's tile system.
  • Allow better customization of layer, source, and tile atlas IDs.
  • Investigate integrations between level tilemaps and Grid/BoardLayer.
• Implement multiple selection as an alternative to shortest path
• Implement turn engine

License

GNU General Public License v3. See LICENSE.