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[Reelya]

BTW shared pointers are especially slow if you pass by value. Always pass them as & or const&

http://stackoverflow.com/questions/3628081/shared-ptr-horrible-speed

^ an algorithm using shared pointers is 10 times slower than the same algorithm using normal pointers. But switching to pass-by-reference for the shared pointers cuts that to only 3 times slower.

You're still going to see significant slowdown by using shared pointers however - the algorithm switches from most of the time doing the actual algorithm to most of the time wrangling pointers unnecessarily.

Generally, my rule of thumb is to avoid things like shared pointers and do memory management myself. But I wrap that up in class/structs: That which calls new, must call delete. Use lightweight wrapper classes for your data structures that need dynamic memory, and avoid virtual functions most of the time.

[RoguelikeRazuka]

Hey could you please suggest me a more or less simple python 2d graphics library for drawing images and 2d primitives on the screen? The task is to write a program that illustrates how binary search tree rotation is performed. That is, I need to get a binary search tree displayed on the screen, two of them to be precise: one that is passed as input and this same tree having some of its nodes shifted due to performing a rotation. The problem is that it's going to take a good screen area to draw merely a single tree (and there must be two of them), so it'd be great to have a window that allows scrolling and (not so necessarily) zooming.

[monkey]

I've tried SceneObject&, but it caused issues with "hitobj = _objects[x];". The reason for all the shared pointers is to handle automatic deletion of objects, and because that's how the instructor had set up the classes.

You could do:

Code: [Select]

bool trace_ray(std::shared_ptr<Vector4> origin, std::shared_ptr<Vector4> dir, SceneObject*& hitobj) const
...
hitobj = _objects[x].get();But yeah, rewrite it without using shared_ptrs, if you want as an exercise for yourself.

Another point against using shared_ptrs is that it is just a reference count, if you have cycles nothing will ever get deleted.
ie. ptrA -> ptrB -> ptrC -> ptrA

[miauw62]

refcounts remind me of further BYOND dumbness. clearing a list by doing listvar = list() (e.g. putting a new list object in the var instead of recycling the old one) would fail to decrement the refcount, and cause a memory leak that persisted through server restarts. the objects sticking around also caused some other issues, such as our master controller (which, as the name implies, is in charge of making sure all the other game controllers tick) spontaneously exploding every other round.

[TheBiggerFish]

That sounds bad.</understatement>

[optimumtact]

refcounts remind me of further BYOND dumbness. clearing a list by doing listvar = list() (e.g. putting a new list object in the var instead of recycling the old one) would fail to decrement the refcount, and cause a memory leak that persisted through server restarts. the objects sticking around also caused some other issues, such as our master controller (which, as the name implies, is in charge of making sure all the other game controllers tick) spontaneously exploding every other round.

Reminds me of a similar one we had where locating on a moveable atoms locs list caused memory corruption in the list structures.
http://www.byond.com/forum/?post=1852790

It caused all the global lists to eventually corrupt and stop acting like global lists and would kill the game servers after a random period of time, the worst part however is that it would just happen slowly over time, so more and more functionality in the game would start silently failing and spewing runtimes.

Ahh byond, truly a worthy game engine.

[itisnotlogical]

Byond is the reason that I only ever played SS13 once, despite having a blast that one time.

[TheBiggerFish]

Why on earth isn't there an ArrayList constructor that takes an Object[] as an argument...

[Shadowlord]

Why on earth isn't there an ArrayList constructor that takes an Object[] as an argument...

But there is. https://msdn.microsoft.com/en-us/library/83h9yskw(v=vs.110).aspx

[miauw62]

Byond is the reason that I only ever played SS13 once, despite having a blast that one time.

Playing in BYOND isn't even that bad.

Coding in dreammaker isn't even that hard.

The language just does a lot of things, deep down, that really, really dont make any sense. You generally don't encounter them until you're doing weird shit, or your codebase is over 350k lines.

Got to keep in mind that BYOND was made somewhere in the early 90s as a MUD making engine, though, and that you could probably still run your shitty 1994 MUD that you made in BYOND version 53 on BYOND version 511. (extreme backwards compatability is part of what has made byond so rotten on the inside)

[TheBiggerFish]

Why on earth isn't there an ArrayList constructor that takes an Object[] as an argument...

But there is. https://msdn.microsoft.com/en-us/library/83h9yskw(v=vs.110).aspx

Java native.

[Shadowlord]

Why on earth isn't there an ArrayList constructor that takes an Object[] as an argument...

But there is. https://msdn.microsoft.com/en-us/library/83h9yskw(v=vs.110).aspx

Java native.

I'm so sorry.

_{(if only youtube also included an 'end at' time, so I could tell it to cut off just before mustafar)}

[MagmaMcFry]

Why on earth isn't there an ArrayList constructor that takes an Object[] as an argument...

You want this?

Code: [Select]

ArrayList list = new ArrayList<Object>(array);

Try this:

Code: [Select]

ArrayList list = new ArrayList<Object>();
Collections.addAll(list, array);

Or this, even better:

Code: [Select]

ArrayList list = new ArrayList<Object>(Arrays.asList(array));


[TheBiggerFish]

Yeah, I found the last one after some Googling, but...Y'know. Kinda weird.

[jaked122]

I'm so sorry.

_{(if only youtube also included an 'end at' time, so I could tell it to cut off just before mustafar)}

Just think, there are people who have chosen to use that programming language knowing of other ones.