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To be honest I use composition over inheritance because it fits better with my mental patterns. I've nothing against OOP in general and I'm pretty sure we can h

To be honest I use composition over inheritance because it fits better with my mental patterns. I've nothing against OOP in general and I'm pretty sure we can have code with good performance also without a component-based model. The fact is just that I'm not as good at designing things with OOP in mind as I'm when I design them with components in mind. But this is me, not a golden rule.

skocznymroczny 8y ago
I like a good balance of composition and inheritance, but I feel like the current hype for ECS is a bit overwhelming. I noticed many beginners are confused and try to shoehorn ECS into EVERY aspect of their game project, as in "OOP/inheritance is lava" way. Also I see people obsessing about performance of ECS vs OOP, when it's not relevant for most of the indie game projects that have a much smaller scope than a high-end AAA game projcet.
- skypjack 8y ago
  I agree that component-based models should not be taken as all-about-performance solutions. I'm using ECS as the core of some software of mine but of course OOP is still present around to treat other aspects and problems that don't fit well with ECS in general. I mean, such an architectural patter solves a specific problem in an elegant way, but it doesn't solve everything in let's say a game. Try to put everything into components is a common mistake that leads to poor code sometimes. However, for those part where it fits, I like to use this architectural pattern because it's closer to the way I think and thus easier to work with for me.
  - HelloNurse 8y ago
    But deep down, it is a performance principle: luxuries like pointers, virtual functions etc. are suitable for complicated but rarely executed code, while important loops should access arrays of components (or something very close) without unnecessary cache misses. If memory accesses were as cheap as 40 years ago, inheritance vs. composition would be a lofty debate about elegance and architecture and programming language semantics and taste; now it has become a much more practical and detailed tradeoff between difficult design and bad performance.
    - reificator 8y ago
      > if memory accesses were as cheap as 40 years ago To clarify for readers not familiar with the motivations here: Memory access is in fact cheaper than it used to be, as you might expect. The concern is that it did not get cheaper nearly as fast as processors got faster, meaning the relative cost of accessing memory became much higher when you could be doing more calculations in that time instead. Specially what allows for better performance is accessing memory in a pattern that can be predicted and prefetched. Linear access is best, because looking up a single byte in memory has approximately the same overhead as looking up a contiguous chunk of bytes. Think Wiley E. Coyote picking up train tracks from behind himself and putting them down in front. If your memory access looks like that then you are less likely to suffer from memory access bottlenecks.
reificator 8y ago
> I've nothing against OOP in general and I'm pretty sure we can have code with good performance also without a component-based model Without a component-based model, sure. But with OOP specifically (which usually just means object hierarchies) you're chasing a lot of pointers and usually (though not always) doing a lot of null checks and other branching inside loops.

skocznymroczny 8y ago

I like a good balance of composition and inheritance, but I feel like the current hype for ECS is a bit overwhelming. I noticed many beginners are confused and try to shoehorn ECS into EVERY aspect of their game project, as in "OOP/inheritance is lava" way. Also I see people obsessing about performance of ECS vs OOP, when it's not relevant for most of the indie game projects that have a much smaller scope than a high-end AAA game projcet.

skypjack 8y ago
I agree that component-based models should not be taken as all-about-performance solutions. I'm using ECS as the core of some software of mine but of course OOP is still present around to treat other aspects and problems that don't fit well with ECS in general. I mean, such an architectural patter solves a specific problem in an elegant way, but it doesn't solve everything in let's say a game. Try to put everything into components is a common mistake that leads to poor code sometimes. However, for those part where it fits, I like to use this architectural pattern because it's closer to the way I think and thus easier to work with for me.
- HelloNurse 8y ago
  But deep down, it is a performance principle: luxuries like pointers, virtual functions etc. are suitable for complicated but rarely executed code, while important loops should access arrays of components (or something very close) without unnecessary cache misses. If memory accesses were as cheap as 40 years ago, inheritance vs. composition would be a lofty debate about elegance and architecture and programming language semantics and taste; now it has become a much more practical and detailed tradeoff between difficult design and bad performance.
  - reificator 8y ago
    > if memory accesses were as cheap as 40 years ago To clarify for readers not familiar with the motivations here: Memory access is in fact cheaper than it used to be, as you might expect. The concern is that it did not get cheaper nearly as fast as processors got faster, meaning the relative cost of accessing memory became much higher when you could be doing more calculations in that time instead. Specially what allows for better performance is accessing memory in a pattern that can be predicted and prefetched. Linear access is best, because looking up a single byte in memory has approximately the same overhead as looking up a contiguous chunk of bytes. Think Wiley E. Coyote picking up train tracks from behind himself and putting them down in front. If your memory access looks like that then you are less likely to suffer from memory access bottlenecks.

reificator 8y ago

> I've nothing against OOP in general and I'm pretty sure we can have code with good performance also without a component-based model Without a component-based model, sure. But with OOP specifically (which usually just means object hierarchies) you're chasing a lot of pointers and usually (though not always) doing a lot of null checks and other branching inside loops.