Grid.cs

using Godot;

// The Grid class represents the spatial properties of a 2x2 grid.
// This class is a static, data-only resource and contains no game logic.
// Can be used in both orthogonal and isometric contexts.
[GlobalClass]
public partial class Grid : Resource
{
    // Size of the grid in cells.
    [Export]
    public Vector2I Size = new(8, 8);

    // Size of each cell in pixels.
    [Export]
    public Vector2I CellSize = new(16, 16);

    // Convert grid cell coordinates to screen coordinates in pixels.
    // Returns the center point of the given cell.
    public Vector2 GridToScreen(Vector2I gridCoords)
    {
        return gridCoords * CellSize + (CellSize / 2);
    }

    // Convert screen coordinates in pixels to grid cell coordinates.
    public Vector2I ScreenToGrid(Vector2 screenCoords)
    {
        Vector2 converted = (screenCoords / CellSize).Floor();
        return new Vector2I((int)converted.X, (int)converted.Y);
    }

    // Returns 'true' if the given grid coordinates are valid.
    public bool IsWithinBounds(Vector2I coords)
    {
        return (
            coords.X >= 0 &&
            coords.X < Size.X &&
            coords.Y >= 0 &&
            coords.Y < Size.Y
        );
    }

    // Clamp the given coordinates to the bounds of the grid.
    public Vector2I Clamp(Vector2I coords)
    {
        return coords.Clamp(Vector2I.Zero, new(Size.X - 1, Size.Y - 1));
    }

    // Serializes grid coordinates as integers such that each cell is uniquely
    // represented. Useful when dealing with A* pathfinding.
    public int ToIndex(Vector2I coords)
    {
        return coords.X + Size.X * coords.Y;
    }
}