3 ms·

But aren't they doing that mostly for performance via better memory layout and thus better cache locality? ie: arrays of objects vs objects of arrays. It's a sa

by _9omd 5y ago

But aren't they doing that mostly for performance via better memory layout and thus better cache locality? ie: arrays of objects vs objects of arrays. It's a sacrifice of code architecture for performance. I feel like games are actually a good example where OOP makes sense, since there is inherently so much state and encapsulation is useful.

skavi 5y ago
Bevy is an ECS based engine, and it’s actually very nice to use. It adds a lot of ergonomics to that experience.
dragonwriter 5y ago
> I feel like games are actually a good example where OOP makes sense Intuitively, yes. In practice, I think once you actually use an ECS for a game you won't want to program them in the traditional OOP way.
lewispollard 5y ago
It's every game dev's first mistake to start adding, say, weapon types to their game by first creating an Item class, then creating a Weapon subclass, Sword inherits that, Shortsword inherits that... And so on. Makes sense, right? It's exactly what OO is for. Except games rarely have that rigid a structure, and maybe you want a sword that also has laser gun features, or an axe that's also a magic staff. That's a lot of subclassing and further dividing up your game objects into rigid hierarchies that become difficult to modify later without unintentionally breaking stuff (was it the logic in the Sword class that grants that damage bonus, or in the Weapon class?) It's nicer to be able to say "I have a weapon entity, I'm going to attach the `SliceDamage" component, the "MagicAttack" component, and so on, and call it a magic axe. It's easier to maintain, it can change at runtime, and the behaviour code only exists in a component file that only does that behaviour, rather than nestled in some lowest common denominator of a hierarchy of classes.

3 ms·

But aren't they doing that mostly for performance via better memory layout and thus better cache locality? ie: arrays of objects vs objects of arrays. It's a sa

by _9omd 5y ago

skavi 5y ago
Bevy is an ECS based engine, and it’s actually very nice to use. It adds a lot of ergonomics to that experience.
dragonwriter 5y ago
> I feel like games are actually a good example where OOP makes sense Intuitively, yes. In practice, I think once you actually use an ECS for a game you won't want to program them in the traditional OOP way.
lewispollard 5y ago
It's every game dev's first mistake to start adding, say, weapon types to their game by first creating an Item class, then creating a Weapon subclass, Sword inherits that, Shortsword inherits that... And so on. Makes sense, right? It's exactly what OO is for. Except games rarely have that rigid a structure, and maybe you want a sword that also has laser gun features, or an axe that's also a magic staff. That's a lot of subclassing and further dividing up your game objects into rigid hierarchies that become difficult to modify later without unintentionally breaking stuff (was it the logic in the Sword class that grants that damage bonus, or in the Weapon class?) It's nicer to be able to say "I have a weapon entity, I'm going to attach the `SliceDamage" component, the "MagicAttack" component, and so on, and call it a magic axe. It's easier to maintain, it can change at runtime, and the behaviour code only exists in a component file that only does that behaviour, rather than nestled in some lowest common denominator of a hierarchy of classes.