GameExample.Map.IsoGrid

IsoGrid.cs

using System;
using System.Collections.Generic;
using Microsoft.Xna.Framework;
using MonoGame.Extended;
using MonoGame.Extended.Shapes;

namespace EGen.Map
{
    public class Grid
    {
        public int Rows { get; }
        public int Cols { get; }
        public int Size { get; }
        public List<Cell> Cells { get; }

        public Grid(int rows, int cols, int size)
        {
            Rows  = rows;
            Cols  = cols;
            Size  = size;
            Cells = new List<Cell>(rows * cols);
            
            for (int r = 0; r < rows; ++r)
                for (int c = 0; c < cols; ++c)
                    Cells.Add(new Cell(this, r, c));
        }

        public Cell GetCell(int row, int col) => Cells[GetIndex(row, col)];

        public int GetIndex(int row, int col)
        {
            int idx = (col - 1) + (row - 1) * Cols;

            if (idx < 0 || idx > Cells.Capacity)
                throw new ArgumentException("Invalid " + (row > Rows ? "Row" : "Col") + " Request.");

            return idx;
        }
    }

    public class Cell
    {
        private readonly Grid _grid;

        public int Row   { get; set; }
        public int Col   { get; set; }
        public int Depth { get; }
        public int Index { get => _grid.GetIndex(Row, Col); }
        
        public float Unit     { get => Dimensions.Width / 2; }
        public float HalfUnit { get => Unit / 2; }

        public Vector2 Position     { get; set; }
        public Size2 Dimensions     { get; set; }
        public RectangleF Container { get; set; }
        
        public Vector2 IsoPosition       { get; }
        public List<Polygon> IsoPolygons { get; }

        public Cell(Grid grid, int row, int col, int depth = 0)
        {
            _grid = grid;
            
            Row   = row;
            Col   = col;
            Depth = depth;

            Dimensions = new Size2(grid.Size, grid.Size);
            Position   = new Vector2((Row - 1) * Dimensions.Height, (Col - 1) * Dimensions.Width);
            Container  = new RectangleF(Position, Dimensions);
            
            List<Vector2> indices = new List<Vector2>
            {
                new Vector2( 0,    0),
                new Vector2( Unit, HalfUnit),
                new Vector2( 0,    Unit),
                new Vector2(-Unit, HalfUnit)
            };
            indices.Add(indices[0].Translate(0, Unit * -Depth));
            indices.Add(indices[1].Translate(0, Unit * -Depth));
            indices.Add(indices[2].Translate(0, Unit * -Depth));
            indices.Add(indices[3].Translate(0, Unit * -Depth));

            IsoPosition = new Vector2((Col - Row) * Unit, (Col + Row) * HalfUnit);
            IsoPolygons = new List<Polygon>() {
                new Polygon(
                    new List<Vector2>(){
                        indices[4], indices[5], indices[6], indices[7]
                    }),
                new Polygon(
                    new List<Vector2>(){
                        indices[7], indices[6], indices[2], indices[3]
                    }),
                new Polygon(
                    new List<Vector2>(){
                        indices[6], indices[5], indices[1], indices[2]
                    })
            };
        }
    }
}