amethyst / rustrogueliketutorial

Roguelike Tutorial in Rust - using RLTK
MIT License
898 stars 156 forks source link

Chapter 61 (Section 5.19) Movement System Teleporting Error #188

Open andreasschmitz opened 2 years ago

andreasschmitz commented 2 years ago

I am wondering if there is an error in chapter 61, which introduces the new movement system.

In the Apply teleports part, we first check if the depth of the teleport and the map's depth are the same. If that's not the case and we are not moving the player, the entity is teleported to another map, as depicted in the following code.

for (entity, teleport) in (&entities, &apply_teleport).join() {
    if teleport.dest_depth == map.depth {
        // omitted
    } else if entity == *player_entity {
        // omitted
    } else if let Some(pos) = position.get(entity) {
        // [...]
        crate::spatial::move_entity(entity, idx, dest_idx);
        other_level.insert(entity, OtherLevelPosition{
            x: teleport.dest_x,
            y: teleport.dest_y,
            depth: teleport.dest_depth })
            .expect("Unable to insert");
        position.remove(entity);
    }
}

Please correct me if I am wrong, but I think we need to remove the entity from the spatial map (crate::spatial::remove_entity) instead of moving it, right? It is not anymore part of the current map. This problems sorts itself out the next time MapIndexingSystem runs, but succeeding systems of the current loop would still see incorrect information.

I am happy to create a pull request with the necessary changes, in case I am right with my assessment.