rutile-game/assets/tilesets/terrain.json

{
    "texture": "terrain.png",
    "tile_size": 32,
    "tiles": [
        {
            "x": 0,
            "y": 0
        },
        {
            "x": 0,
            "y": 0
        },
        {
            "x": 1,
            "y": 0
        },
        {
            "x": 2,
            "y": 0
        },
        {
            "x": 3,
            "y": 0
        }
    ]
}