Count entities

[gamecoder-nz]

Is there a way to count the number of entities that have a given set of components?

[skypjack]

It depends on the set actually. Single type views have a size method that returns the exact number of elements while multi-type views have a size_hint method that return the upper bound. The only way to know the exact number in the last case is by visiting the set instead.

[gamecoder-nz]

Ok so I would need to keep track of the count myself somehow

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On Tue, 17 Oct 2023, 9:48 pm Michele Caini, ***@***.***> wrote: It depends on the set actually. Single type views have a size method that returns the exact number of elements while multi-type views have a size_hint method that return the upper bound. The only way to know the exact number in the last case is by visiting the set instead. — Reply to this email directly, view it on GitHub <#1077 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AKHPB7RLUMUVY4QONAP5THLX7ZA5FAVCNFSM6AAAAAA6C7DBI2VHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM3TGMBRGQ2DO> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[skypjack]

It's hard to say. It smells of XY-problem to be honest. What's the purpose? I really can't help without a bit of context.

[gamecoder-nz]

So I have a star spawner system. If the number of stars in the game is less than 5 then create a new one. If there are already 5 stars then move the oldest one. In the collision detection system the star will be destroyed if the player touches it. I want to keep the systems separate and not communicate with each other. I originally had the size method because I was only finding entities with a star component but I also need to exclude another component which means a lose the size method

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On Tue, 17 Oct 2023, 10:00 pm Michele Caini, ***@***.***> wrote: It's hard to say. It smells of XY-problem to be honest. What's the purpose? I really can't help without a bit of context. — Reply to this email directly, view it on GitHub <#1077 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AKHPB7TO6QPZDHITBWMVZDDX7ZCJHAVCNFSM6AAAAAA6C7DBI2VHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM3TGMBRGU4TM> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[skypjack]

Well it depends, if the second component is assigned only to stars you have technically transformed the problem into a subtraction. 🤷‍♂️