Monogame-Extended/tests/MonoGame.Extended.Tests/Tilemaps/TilemapTests.cs

using Microsoft.Xna.Framework;
using MonoGame.Extended.Tilemaps;

namespace MonoGame.Extended.Tests;

public sealed class TilemapTests
{
    #region Orthogonal Coordinate Tesets

    [Fact]
    public void TileToWorldPosition_Orthogonal_Origin_ReturnsZero()
    {
        var tilemap = new Tilemap("test", 10, 10, 32, 32, TilemapOrientation.Orthogonal);
        var worldPos = tilemap.TileToWorldPosition(0, 0);
        Assert.Equal(new Point(0, 0), worldPos);
    }

    [Theory]
    [InlineData(0, 0, 0, 0)]
    [InlineData(1, 0, 32, 0)]
    [InlineData(0, 1, 0, 32)]
    [InlineData(1, 1, 32, 32)]
    [InlineData(5, 3, 160, 96)]
    [InlineData(10, 10, 320, 320)]
    public void TileToWorldPosition_Orthogonal_VariousCoodinates_ReturnsExpectedPositions(int tileX, int tileY, int expectedworldX, int expectedWorldY)
    {
        var tilemap = new Tilemap("test", 20, 20, 32, 32, TilemapOrientation.Orthogonal);
        var worldPos = tilemap.TileToWorldPosition(tileX, tileY);
        Assert.Equal(new Point(expectedworldX, expectedWorldY), worldPos);
    }

    [Fact]
    public void WorldToTilePosition_Orthogonal_Origin_ReturnsZero()
    {
        var tilemap = new Tilemap("test", 10, 10, 32, 32, TilemapOrientation.Orthogonal);
        var tilePos = tilemap.WorldToTilePosition(Vector2.Zero);
        Assert.Equal(Point.Zero, tilePos);
    }

    [Theory]
    [InlineData(0, 0, 0, 0)]
    [InlineData(32, 0, 1, 0)]
    [InlineData(0, 32, 0, 1)]
    [InlineData(32, 32, 1, 1)]
    [InlineData(160, 96, 5, 3)]
    [InlineData(320, 320, 10, 10)]
    public void WorldToTilePosition_Orthogonal_VariousPositions_ReturnsExpectedCoordinates(float worldX, float worldY, int expectedTileX, int expectedTileY)
    {
        var tilemap = new Tilemap("test", 20, 20, 32, 32, TilemapOrientation.Orthogonal);
        var tilePos = tilemap.WorldToTilePosition(new Vector2(worldX, worldY));
        Assert.Equal(new Point(expectedTileX, expectedTileY), tilePos);
    }

    [Fact]
    public void CoordinateTransformation_Orthogonal_RoundTrip_PreservesCoordinates()
    {
        var tilemap = new Tilemap("test", 20, 20, 32, 32, TilemapOrientation.Orthogonal);
        var originalTile = new Point(5, 7);

        var worldPos = tilemap.TileToWorldPosition(originalTile.X, originalTile.Y);
        var backToTile = tilemap.WorldToTilePosition(new Vector2(worldPos.X, worldPos.Y));

        Assert.Equal(originalTile, backToTile);
    }

    [Fact]
    public void WorldBounds_Orthogonal_ReturnsCorrectBounds()
    {
        var tilemap = new Tilemap("test", 10, 8, 32, 32, TilemapOrientation.Orthogonal);
        var bounds = tilemap.WorldBounds;
        Assert.Equal(new Rectangle(0, 0, 320, 256), bounds);
    }

    #endregion

    #region Isometric Coordinate Tests

    [Fact]
    public void TileToWorldPosition_Isometric_Origin_ReturnsZero()
    {
        var tilemap = new Tilemap("test", 10, 10, 64, 32, TilemapOrientation.Isometric);
        var worldPos = tilemap.TileToWorldPosition(0, 0);
        Assert.Equal(Point.Zero, worldPos);
    }

    [Theory]
    [InlineData(1, 0, 32, 16)]   // (1-0)*(64/2), (1+0)*(32/2)
    [InlineData(0, 1, -32, 16)]  // (0-1)*(64/2), (0+1)*(32/2)
    [InlineData(1, 1, 0, 32)]    // (1-1)*(64/2), (1+1)*(32/2)
    [InlineData(2, 1, 32, 48)]   // (2-1)*(64/2), (2+1)*(32/2)
    public void TileToWorldPosition_Isometric_VariousCoordinates_ReturnsExpectedPositions(int tileX, int tileY, int expectedWorldX, int expectedWorldY)
    {
        var tilemap = new Tilemap("test", 10, 10, 64, 32, TilemapOrientation.Isometric);
        var worldPos = tilemap.TileToWorldPosition(tileX, tileY);
        Assert.Equal(new Point(expectedWorldX, expectedWorldY), worldPos);
    }

    [Fact]
    public void WorldToTilePosition_Isometric_Origin_ReturnsZero()
    {
        var tilemap = new Tilemap("test", 10, 10, 64, 32, TilemapOrientation.Isometric);
        var tilePos = tilemap.WorldToTilePosition(new Vector2(0, 0));
        Assert.Equal(Point.Zero, tilePos);
    }

    [Fact]
    public void CoordinateTransformation_Isometric_RoundTrip_PreservesCoordinates()
    {
        var tilemap = new Tilemap("test", 10, 10, 64, 32, TilemapOrientation.Isometric);
        var originalTile = new Point(5, 3);

        var worldPos = tilemap.TileToWorldPosition(originalTile.X, originalTile.Y);
        var backToTile = tilemap.WorldToTilePosition(new Vector2(worldPos.X, worldPos.Y));

        Assert.Equal(originalTile, backToTile);
    }

    [Fact]
    public void WorldBounds_Isometric_ReturnsCorrectBounds()
    {
        var tilemap = new Tilemap("test", 10, 8, 64, 32, TilemapOrientation.Isometric);
        var bounds = tilemap.WorldBounds;

        // (10 + 8) * (64/2) = 18 * 32 = 576 width
        // (10 + 8) * (32/2) = 18 * 16 = 288 height
        Assert.Equal(new Rectangle(0, 0, 576, 288), bounds);
    }

    #endregion

    #region Different Tile Sizes

    [Theory]
    [InlineData(16, 16)]
    [InlineData(32, 32)]
    [InlineData(64, 64)]
    [InlineData(48, 24)]
    public void TileToWorldPosition_Orthogonal_DifferentTileSizes_WorksCorrectly(int tileWidth, int tileHeight)
    {
        var tilemap = new Tilemap("test", 10, 10, tileWidth, tileHeight, TilemapOrientation.Orthogonal);
        var worldPos = tilemap.TileToWorldPosition(3, 2);
        Assert.Equal(new Point(3 * tileWidth, 2 * tileHeight), worldPos);
    }

    #endregion

    #region Edge Cases

    [Fact]
    public void TileToWorldPosition_NegativeCoordinates_HandlesCorrectly()
    {
        var tilemap = new Tilemap("test", 10, 10, 32, 32, TilemapOrientation.Orthogonal);
        var worldPos = tilemap.TileToWorldPosition(-1, -2);
        Assert.Equal(new Point(-32, -64), worldPos);
    }

    [Fact]
    public void WorldToTilePosition_NegativeWorldPosition_HandlesCorrectly()
    {
        var tilemap = new Tilemap("test", 10, 10, 32, 32, TilemapOrientation.Orthogonal);
        var tilePos = tilemap.WorldToTilePosition(new Vector2(-32, -64));
        Assert.Equal(new Point(-1, -2), tilePos);
    }

    [Fact]
    public void WorldToTilePosition_FractionalWorldPosition_TruncatesDown()
    {
        var tilemap = new Tilemap("test", 10, 10, 32, 32, TilemapOrientation.Orthogonal);
        var tilePos = tilemap.WorldToTilePosition(new Vector2(50.7f, 70.9f));

        // 50/32 = 1.5 -> 1
        // 70/32 = 2.1 -> 2
        Assert.Equal(new Point(1, 2), tilePos);
    }

    #endregion
}