Exposes a set of tiles for a [TileSet] resource. Exposes a set of tiles for a [TileSet] resource. Tiles in a source are indexed with two IDs, coordinates ID (of type Vector2i) and an alternative ID (of type int), named according to their use in the [TileSetAtlasSource] class. Depending on the TileSet source type, those IDs might have restrictions on their values, this is why the base [TileSetSource] class only exposes getters for them. You can iterate over all tiles exposed by a TileSetSource by first iterating over coordinates IDs using [method get_tiles_count] and [method get_tile_id], then over alternative IDs using [method get_alternative_tiles_count] and [method get_alternative_tile_id]. Returns the alternative ID for the tile with coordinates ID [param atlas_coords] at index [param index]. Returns the number of alternatives tiles for the coordinates ID [param atlas_coords]. For [TileSetAtlasSource], this always return at least 1, as the base tile with ID 0 is always part of the alternatives list. Returns -1 if there is not tile at the given coords. Returns the tile coordinates ID of the tile with index [param index]. Returns how many tiles this atlas source defines (not including alternative tiles). Returns if the base tile at coordinates [param atlas_coords] has an alternative with ID [param alternative_tile]. Returns if this atlas has a tile with coordinates ID [param atlas_coords].