REALLY fast collection - for stuff like bullets and enemies in a game! ;)

[Jotaf98]

Hey all, I just developed a new technique that makes it so that you *NEVER* have to use loops to create and destroy objects in an array in a game (looking for an inactive object and stuff) - and as you know, these loops really slow down a game. My technique is really simple and very easy to implement. I made a small sample but the only part you really need is like 20 lines long (2 functions - CreateBullet() and DeleteBullet() ). No credits needed

[Sastraxi]

I already do my stuff in a way similar to that

[Fox]

@Jotaf98: lol...

And soon you'll find out about objects and collections.

[Sastraxi]

Jotaf, I read over all your stuff and it's nice, but I wouldn't market it as a new technique, like Fox has implied (if I read it right, lol).

[Rag on a Stick]

Sorry, I can't download the code right now, so I can't actually comment on it specifically, but 2 really quick methods I have used are:

1) Dynamic array with a bit smarter memory management. Each element has an "Exists" property and it allocates memory in large chunks so Redim calls are minimised (they are quite slow, especially when it is Redim Preserve).

2) Dictionary object: similar to the collection object, can be used by referencing the Microsoft Scripting Runtime. Usage is almost identical to a collection with a couple of changes (you can't directly copy paste, but it is intuitive). Stores objects by a key which can be anything - numbers, strings, UDTs etc. Behind the scenes it is just a hash table (like the collection). But it is a lot quicker.

[Jotaf98]

Lol of course you all do it in a similar way - I saw all your code samples just like everyone else and the only new thing about it is a small detail that makes it so you don't need to loop to look for inactive members: the stack of pointers to free slots in the array... the rest is exactly like most people do, and as to collections and objects, I made a few tests and this way it's a LOT faster

Huh Rag it's exactly like your first technique except that you don't need to search for inactive objects...

[Sastraxi]

How do you know its not how I do it I did it that way in my Winsock multiple downloading program.. of course it didn't need that speed, but thats how it was

Cool code though.

[Jotaf98]

Heh ok... It's just that I never saw this in any program, and it has a huge advantage for such a small amount of code, so I thought I would share it.

[Sastraxi]

If I hadn't known about it, I would've used it after.. well, kind of.. errr... yeah..... disregard this post please

[Fox]

I'm using this technique since ages.. also I made a little more complex management to delete items. Basically it just copies the last item of the array to the one that's going to be deleted, then cut the last item and change the 'pointer' to the new index. This way you don't even have to check for inactive members

[yrwyddfa]

well aren't you a little clever bunny, then

[Zaei]

Thats how I do it, Fox. A quick swap, decrement the size (you dont even have to resize the array, just keep values for filled and total, and only resize when you exit, or need more space), and youre done. Linked Lists are also great for object managment, but since VB isnt very good at inheritance, and doesnt support templating at all, you would have to re-implement everything for every object type that you have.

Z.

[yrwyddfa]

I would have been tempted to use GlobalAlloc to allocate memory directly rather than use a safearray . . .

[Fox]

I didn't say any word about ReDimming ^^

[Zaei]

I didnt mean ReDim (unless you run out of space, of course). I was simply referring to holding a size value =).

Z.

[Jotaf98]

Heh I had never thought of that Fox, yes it's a great idea (I wonder how I never thought of that )

I also keep a size value and never redim the arrays (unless I need more memory). Sometimes what I do is redim it for more 100 items or something and keep the size valuelower so I don't have to redim it a lot of times

[Zaei]

Exactly, Jotaf =).

Z.

[Jotaf98]

Heh

Hey what do you think if we wrote an article or something on these techniques... I had to figure them out by myself... what a waste of brain power

[danday1974]

JOTAF

A tutorials sounds good since I have no idea wot u guys r on about

Dan

[Sastraxi]

Uh-oh, another Jotaf community project... lol

[Jotaf98]

Lol com'on sas, you're talking like if I ever did something like that (or do it all the time)

[Sastraxi]

You made a community project out of your particle systems thing, we all chipped in

[dafhi]

It is now mid-November. I think I read this thread in September. I downloaded your file and read some of your comments. Didn't really click at the time but what did make sense "in the back of my mind" was pulling an element from the top. It's about 2 days now that I've had my own stack-based recycling system running. I use 2 stacks, and each has its own pointer. It is 'your original idea' that sparked my system. Thanks

[Jotaf98]

Heh you're welcome dafhi, I'm glad it was of some use to you

Sas yeah you're right lol sorry I didn't reply... I haven't really coded anything for the past few weeks (months?), busy with hmm social life and stuff
I learned some C++ though and made a few simple projects and all. Oh well. Maybe some day I'll come back. I wanted to code a game in C++ but somehow I like VB much better, the syntax and all is much more hmm "confy". Yeah, that.

Oh Fox, there's a huge glitch in your technique, it kinda screws up the indexes I think... my way the indexes never ever change.

Well, later I guess, I don't surf the forums anymore but you can still find me on MSN Messenger

[Sastraxi]

Yeah, I was just about to call you the genie (only comes when somebody calls him )

Catch you later, I suppose!

[Jotaf98]

Yeah, rub the lamp and I always show up... hmm... my e-mail is [email protected] , I'm usually online since I have a nice cable connection hehe