createFromObjects incorrect object position for isometric tiled map

[ddanushkin]

Version

• Phaser Version: 3.80.1
• Operating system: Windows 11
• Browser: Edge

Description

I wanted to create the tilemap objects myself and copied logic from here
But the positions of the objects were not correct

I created a new map and got exactly the same result with createFromObjects

Example Test Code

const tilemap = this.add.tilemap(Timemaps.test);

const tile_grass = tilemap.addTilesetImage('tile_grass', Images.tile_grass)!;
tilemap.createLayer('Tile Layer 1', tile_grass);

tilemap.createFromObjects('Object Layer 1', {
    gid: 2,
    key: Images.marker
});

Tiled JSON

{
    "compressionlevel": -1,
    "height": 4,
    "infinite": false,
    "layers": [
        {
            "data": [
                1,
                1,
                1,
                1,
                1,
                1,
                1,
                1,
                1,
                1,
                1,
                1,
                1,
                1,
                1,
                1
            ],
            "height": 4,
            "id": 1,
            "name": "Tile Layer 1",
            "opacity": 1,
            "type": "tilelayer",
            "visible": true,
            "width": 4,
            "x": 0,
            "y": 0
        },
        {
            "draworder": "topdown",
            "id": 2,
            "name": "Object Layer 1",
            "objects": [
                {
                    "gid": 2,
                    "height": 40,
                    "id": 1,
                    "name": "",
                    "rotation": 0,
                    "type": "",
                    "visible": true,
                    "width": 40,
                    "x": 178.41935483871,
                    "y": 179.58064516129
                }
            ],
            "opacity": 1,
            "type": "objectgroup",
            "visible": true,
            "x": 0,
            "y": 0
        }
    ],
    "nextlayerid": 3,
    "nextobjectid": 2,
    "orientation": "isometric",
    "renderorder": "right-down",
    "tiledversion": "1.10.2",
    "tileheight": 108,
    "tilesets": [
        {
            "columns": 1,
            "firstgid": 1,
            "image": "tile_grass.png",
            "imageheight": 108,
            "imagewidth": 186,
            "margin": 0,
            "name": "tile_grass",
            "spacing": 0,
            "tilecount": 1,
            "tileheight": 108,
            "tilewidth": 186
        },
        {
            "columns": 0,
            "firstgid": 2,
            "grid": {
                "height": 1,
                "orientation": "orthogonal",
                "width": 1
            },
            "margin": 0,
            "name": "marker",
            "spacing": 0,
            "tilecount": 1,
            "tileheight": 40,
            "tiles": [
                {
                    "id": 0,
                    "image": "marker.png",
                    "imageheight": 40,
                    "imagewidth": 40
                }
            ],
            "tilewidth": 40
        }
    ],
    "tilewidth": 186,
    "type": "map",
    "version": "1.10",
    "width": 4
}

[ddanushkin]

I managed to solve my problem
I used this code from tiled as reference
I dont know if it breaks while scale/rotate objects in tiled, but if works for me)

const tilemap = this.add.tilemap(Timemaps.test);

const tileWidth = tilemap.tileWidth;
const halfTileWidth = tileWidth * 0.5;
const tileHeight = tilemap.tileHeight;
const originX = tilemap.height * tileWidth * 0.5;

const tile_grass = tilemap.addTilesetImage('tile_grass', Images.tile_grass)!;

const layer = tilemap.createLayer('Tile Layer 1', tile_grass)!;

//! Layer position fix
const tilemapWidth = tilemap.widthInPixels;
const halfTilemapWidth = tilemapWidth * 0.5;
layer.setPosition(halfTilemapWidth - halfTileWidth, 0);

const objects = tilemap.objects[0].objects;
for (let i = 0; i < objects.length; i++) {
     //! Ref: https://github.com/mapeditor/tiled/blob/12ca7077d3d5cd9655929030092681a986dd749a/src/libtiled/isometricrenderer.cpp#L495-L505
    const object = objects[i];

    const tileY = object.y! / tileHeight;
    const tileX = object.x! / tileHeight;

    const x = (tileX - tileY) * tileWidth * 0.5 + originX;
    const y = (tileX + tileY) * tileHeight * 0.5;

    const sprite = this.add.sprite(x, y, (Images as any)[object.name]);
    sprite.setOrigin(0.5, 1);
}

About "Layer position fix" part, layer getBounds doesn't match its rendered position

layer.setInteractive();
this.input.enableDebug(layer, 0);

[ivryb]

@ddanushkin you are the beast! Thank you!

I spent more than a day on this.

I had a lot of map layers and "layer position fix" just broke my game, but I iterated a bit and found an alternative.

const tileWidth = tilemap.tileWidth;
const tileHeight = tilemap.tileHeight;

// magic offset difference between tiled and phaser
const offsetY = tileHeight * 3;
const offsetX = tileWidth / 2;

const convertObjectCoordinates = (object) => {
  const tileY = object.y / tileHeight;
  const tileX = object.x / tileHeight;

  const x = offsetX + (tileX - tileY) * tileWidth * 0.5;
  const y = offsetY + (tileX + tileY) * tileHeight * 0.5;

  return { x, y };
};

const objectLayer = tilemap.getObjectLayer("objects");
const objects = objectLayer.objects;

objects.map((item) => {
  const { x, y } = convertObjectCoordinates(item);

  scene.add
    .text(x, y, `I'm here!`, {
      fontSize: "16px",
      color: "#ffff00",
      stroke: "#000000",
      strokeThickness: 4,
      align: "center",
    })
    .setOrigin(0.5)
});