Game Development

In object-oriented computer programming, a Null Object is an object with defined neutral ("null") behavior. The Null Object design pattern describes the uses of such objects and their behavior (or lack thereof). It was first published in the Pattern Languages of Program Design book series. Motivation In most object-oriented languages, such as Java or C#, references may be null. These references need to be checked to ensure they are not null before invoking any methods, because methods typically cannot be invoked on null references. The Objective-C language takes another approach to this ...

Shotgun Ninja

That's still null...

Kikaimaru

@ShotgunNinja its just a name

but thats not the point, point is that it woudlnt be implicitly set to null (or null object)

Shotgun Ninja

It's a good pattern, but there are situations in which it wouldn't apply...

Kikaimaru

@ShotgunNinja like?

Shotgun Ninja

Well, they aren't really valid if you're designing your own language... spoke too soon.

For one, though, you'd have to have your language generate null-object versions of all data types.

Kikaimaru

2:16 PM

as I've said

public class Person
{
public Person Mother;
}

this construction would be invalid

since mother is not specified

public class Person
{
public Person Mother;
public Person(Person mother) { this.Mother = mother ;}
}

this would be valid though

Shotgun Ninja

@Kikaimaru I'd think that'd be invalid anyway, since (at least in C++) you're declaring an instance of a class within its definition.

@Kikaimaru That'd be valid in C# or Java already.

Almo

I think

Shotgun Ninja

But for a different reason.

Kikaimaru

@ShotgunNinja what? point is that the first declaration allows you to create Person and have Mother field null - which is not possible

Shotgun Ninja

@Kikaimaru In C++, that wouldn't be a pointer. There's no asterisk.

Kikaimaru

2:18 PM

second class declaration doesnt do that, since you have to pass mother in constructor (in non nullable type argument)

Shotgun Ninja

It'd be an instance of the object, which it needs to know the size of in order to compute the size of the containing class.

Kikaimaru

@ShotgunNinja its my new language derived from c# with no nullable types

@ShotgunNinja its not a pointer but reference

Shotgun Ninja

@Kikaimaru Hence why I specified IN C++.

Kikaimaru

@ShotgunNinja but its my code, you cant specifiy what language i used :)

Shotgun Ninja

It may not have been a useful comment, but it's a valid one.

Kikaimaru

2:19 PM

ok? :)

Almo

KO

Shotgun Ninja

Kay-OH!

Almo

I love how in Tekken Bowl, when you get a spare, it says in its serious KO voice "Oh Kay"

Kikaimaru

point is that with non nullable types, there would be bunch of compile time errors that would prevent runtime null reference exceptions

Almo

but often you can't tell at compile time if it's null or not

Shotgun Ninja

2:21 PM

Matt D

im oldschool. i like null. some people have a problem with it. i dont :)

Kikaimaru

@Almo since in my language with no nullable types, there is nothing that is null, you can

Matt D

i actually find it very annoying to use languages where there is no null. beacuse then you just end up expressing the lack of something another, shittier way

Shotgun Ninja

I just think that a null object pattern is useful in how it simplifies code, but dangerous in how it hides details. A lot of programmers I know can recognize a null-check, and understand its importance. If there isn't one, most people I know would assume that the object either can't be supplied as null by design, or is checked for elsewhere.

Almo

Doesn't sound like it helps, to me

you still have to check if your object creation failed or not, in some other way

why not use null for that

Kikaimaru

2:24 PM

@Almo what?

Shotgun Ninja

It'd be like there being no security checkpoint at an airport. Even if there is an advanced X-ray system across the main entry point, and equipment to label security threats for later questioning without obstructing traffic, it still seems wrong.

Matt D

the real answer is "it depends". there are times when "null" sucks. and there are times when its great. object creation is interesting. for games, a lot of the time you want a "ghost" object while you load in data behind that. you cant really deal with having "null" in that instance. as you have "something". when you're not dealing with async stuff null i feel is perfectly valid way of saying "this didnt work/go as expected". the alternative to that is what exactly? exceptions? just as terrible.

Almo

Say you create a person with an age of -1. What does your language allow for saying that failed? In C, we'd just return a null pointer, and you do "if(personPointer)"

Matt D

you could have an exception to catch that case. but thats a rare thing for games(tm)

Kikaimaru

@Almo object creation cannot ever fail, like var person = new Person() will always fill person variable

Almo

2:28 PM

A person with -1 age is invalid. returning a null person tells you that it was invalid very simply

Matt D

you can actually throw from within new in c# ;)

Almo

in a way that's the same across all pointers you create

Kikaimaru

@Almo as Matt said i would throw an exception

since something exceptional is happening

Matt D

throwing from constructors though. thats murky territory for c++

Almo

Which as Matt also says, exceptions are not so much better than null as they're messy to handle.

Matt D

2:29 PM

i would be checking parashift for WTF happens when you do that

Kikaimaru

@MattD well its not c++

@Almo i dont agree with that

Matt D

id still be cautious in c# tbh

Shotgun Ninja

Basically, I feel Null Object Pattern is useful when you can afford to treat the lack of an object like a real object (think open-road tolling; you want null objects to continue on and not obstruct real objects, and you'll catch them later by their license plate), but it's not useful when the distinction of a null object is something you want to use for control flow, since then it just makes that more complicated.

Matt D

exceptions do weird shit

Kikaimaru

not in c#

Matt D

2:30 PM

they screw up execution flow

Kikaimaru

@MattD yes but in a good way

Matt D

i really should read up on them more :)

Shotgun Ninja

@MattD They unwind the stack.

Kikaimaru

you just shouldnt use them for controling execution flow :)

Matt D

thats what they seem to get used for these days

Kikaimaru

2:31 PM

btw creating person with age -1 would never happen, because that value is probably from user input which would be checked

Matt D

"oh something minor happened ill throw an exception"

well, thats an interesting point too

Kikaimaru

so it would be if (age < 0) alertuser else createperson

Almo

Saying something will never happen is asking for trouble.

Matt D

where do you keep the state that checks to see if thats a valid user?

do you package that WITH the class istelf? or outside the class?

Kikaimaru

@MattD no thats not what exceptions are for, exceptions are for something thats unpredictible

Shotgun Ninja

2:31 PM

Now, Null Objects are useful as a form of the Mock Object pattern.

Matt D

also, patterns. you guys scare me with how you reference patterns :P

Kikaimaru

@Almo no its not, i say that it will not happen so thats why i wont throw exception because of it, because its error in source code

Shotgun Ninja

Patterns are just names of things that are useful in certain conditions.

Almo

Exiting argument; no further purpose.

Shotgun Ninja

Hey @Noct, did someone flag something?

Matt D

2:33 PM

almo: was that an exceptional argument point? ;)

Shotgun Ninja

I know there was a heated discussion about the Null Object pattern, but if you're coming in here, there's probably a reason

Matt D

ill refer back to my actual proper answer ;)

i guess its quite personal as how you approach the concept of "nothingness" is quite integral to how one looks and and decomposes problems. and people approaching problems with a difference concept to yours can be quite confronting. even if the approach is just as valuable in resulting execution

but thats kind of the reason why programmers love semantic arguments too

Shotgun Ninja

@MattD looks at*

Kikaimaru

you know what i would also add to my language? contracts as part of method signature! :)

Shotgun Ninja

@Kikaimaru Contracts for what purpose?

Kikaimaru

2:40 PM

@ShotgunNinja well for example for this setAge(int age) requires age > 0

Shotgun Ninja

@Kikaimaru Oh, that makes sense. Doesn't Pascal do something like that? Or am I getting it mixed up with a different language?

Kikaimaru

@ShotgunNinja Spec# and C# 4.0 can do that

Shotgun Ninja

I know there's at least one language out there that specifies preconditions and contracts for data in the signature.

Matt D

its ok for POD stuff. but it can get awkward for complicated data types

Alex M.

@ShotgunNinja Eiffel

Shotgun Ninja

2:41 PM

@AlexM. Yeah, that was it

Alex M.

Eiffel owns the trademark of "Design by Contract"

Kikaimaru

or you can do interface IList { sort() ensures "listsorted" };

i dont know from head how to write listsorted, but its possible :)

and then when someone implements sort method, he has to make sure that it actually sorts the list

Matt D

you're almost getting into TDD territory

Kikaimaru

or PEX will find out and throw compilation error!

:)

Matt D

as thats not really useful for runtimes ;)

Kikaimaru

2:44 PM

no this should work at compile time

which would be awesome

Matt D

oh hell its almost 1am

TheProgramm3r

:D

Kikaimaru

http://angler.wordpress.com/2010/02/01/code-contracts-pex-assertions-and-assumptions-for-expressive-tests/

look at this, its how code contracts and pex are used together

Shotgun Ninja

That's kinda cool.

Alex M.

you can see the difference between Eiffel and C# though

with the first being made for such things

and the latter merely adopting the methodology

Kikaimaru

2:48 PM

there is Spec# that was made with this too, and it has nonnullable types too :) using Person! Mother

Shotgun Ninja

lol, reps from the Archdiosese of Milwaukee are standing behind me.

Alex M.

I would have added the pre/post/invariants above the method's header in Spec#

it looks ugly with them below it

Kikaimaru

i like it bellow, its like throws in java

Alex M.

imo, outside Eiffel, cofoja has the best syntax with contract info described above methods and class declarations

interface Time {
  ...

  @Ensures({
    "result >= 0",
    "result <= 23"
  })
  int getHour();

  @Requires({
    "h >= 0",
    "h <= 23"
  })
  @Ensures("getHour() == h")
  void setHour(int h);

  ...
}

Matt D

but thats a runtime check

Kikaimaru

2:51 PM

but thats strings, is there compile time checking if its valid?

Alex M.

code.google.com/p/cofoja

Matt D

would be cool for TDD

Alex M.

it's at runtime, yes

Kikaimaru

code.google.com/p/blockly

btw do you know this?

Matt D

ok bedtime. night folks.

Alex M.

2:53 PM

I find contracts are most useful at runtime

because you know, that's when you call/pass/whatever things that are outside the contract

@Kikaimaru I think the whole internet now knows about it

Almo

blockly appears to be based on the Lego Mindstorms editor

Kikaimaru

@AlexM. i doubt thats true

Alex M.

of course it isn't true, my mum doesn't know about it, har har

Kikaimaru

@AlexM. your mother might not be part of the internet though

Alex M.

she is, she does have a Facebook account

Kikaimaru

2:55 PM

maybe your mother is so big that she cant be allocated with a IPv6 address

Alex M.

now now, let's not get ahead of ourselves.

KitFox

I'm sorry, that was really funny.

Everything OK in here?

Kikaimaru

ehm who are you? :)

Shotgun Ninja

Yeah. Did someone flag?

Alex M.

all's fine, of course

KitFox

2:58 PM

Very well then. Carry on.

Almo

Uh ok. :)

Shotgun Ninja

Carry On (Fun song)

"Carry On" is a song by American indie band Fun. It was released on 23 October 2012 as the third single off their second album, Some Nights. The song was written by the band members, Nate Ruess, Andrew Dost, Jack Antonoff, alongside the album's producer, Jeff Bhasker. It is also featured in the HGTV 2013 #LoveHome commercial airing on American TV. The song was also featured the highlight clip for the 2012-13 PBA Philippine Cup Finals. Composition "Carry On" has been called "a song about perseverance in hard times", which is supported by a rock-anthem sound composed in 12/8 time. The son...

ClassicThunder

Is that a cover of the Kansas song?

KitFox

in English Language & Usage, 43 secs ago, by Mr. Shiny and New 安宇

@KitFox Shouldn't she just use BGP, and allocate a block of addresses?

Shotgun Ninja

@ClassicThunder Very far from it. FUN performed it at the 2013 Grammy Awards.

►

It's a 12/8ths-time rock anthem to perseverance.

Almo

3:05 PM

12/8?

that's an unusual signature

here's something weird... Techno in 3/4. youtube.com/watch?v=uJutu3POGwk

that album is littered with weird time signatures

Shotgun Ninja

It's a ~~sped-up~~ waltzy version of an Irish drinking song mixed with a Queen rock anthem.

It's not really sped up, it's just divided further than the usual 4/3 time.

You only hear it in the supporting drum beats, though.

Almo

ok

Shotgun Ninja

It incorporates a waltzy 1-2-3, but four times per measure.

hence, 12 eighths.

John McDonald

Interesting

Shotgun Ninja

Well, it peaked at 20 on the Billboard Top 100.

Almo

3:10 PM

that's a lotta copies sold

Shotgun Ninja

and I got to see it performed live last Thursday.

squeee

John McDonald

Oh I've heard the song tonnes of times before, just never noticed the timing structure

Shotgun Ninja

Here's another lesser-known one by them that's still rather good.

►

Almo

he claims not to think about time signatures

contactmusic.com/interview/interview-with-fun-may-2012

the Bee Gees couldn't read music.

Shotgun Ninja

He also says he wants to collaborate with Skrillex, which would be fucking ridiculous.

codemonkey

3:18 PM

hey everyone

whats a good room for C++?

Shotgun Ninja

And a really fun one:

►

codemonkey

I mean, whether gamedev related or not

is there a cpp chat room?

Shotgun Ninja

Lounge<C++>

Today we're daydreaming about C++26 reflection

10

codemonkey

@shog

@ShotgunNinja thanks

and how about OpenGL? I'm failing the search hard

Shotgun Ninja

They're all jerks, and half of them contribute to the language spec, so be careful what you admit.

Learn from them, just don't admit how little you know.

codemonkey

3:19 PM

hahahaha, sure

Shotgun Ninja

They actually hate answering questions, no joke.

codemonkey

thanks for the advice

Shotgun Ninja

as in the tag no-helpdesk

codemonkey

ill just try to listen in :D

Alex M.

hey @Almo, got some Obj-C code near you?

I wanna... visit the cpp lounge

Shotgun Ninja

3:21 PM

the big thing is, you can ask, but you'd have to ask everything, because if you say you know something, they'll prove that you're wrong or at least unclear on what you know.

For example, don't call it the standard template library.

It's the C++ Standard Library.

codemonkey

really? how come :D

Shotgun Ninja

STL is a copyright of Silicon Graphics Inc.

The C++ Standard Library is the one mistakenly referred to as the STL all the time.

codemonkey

ah, ok...

Shotgun Ninja

Stuff like that.

All over the place.

codemonkey

perhaps this is the better C++ channel? :D

Shotgun Ninja

3:22 PM

Maybe. We're at least somewhat knowledgeable in practical C++ usage, or at least some of us are.

in Lounge<C++> on Stack Overflow Chat, 1 min ago, by rightfold

> Your brain is still in your dick, which you don't have anymore.

codemonkey

lol

yeah

Alex M.

that place is very flaggable

codemonkey

saw that

Alex M.

okay, let's see how they react to objc code

Shotgun Ninja

nice.

Almo

3:25 PM

m_clipCards = [[NSMutableArray array] retain];
m_unclipCards = [[NSMutableArray array] retain];

[self setCardSlotType:e_CST_carousel];
[self setCardAvailability:e_cardAvailability_all];

Shotgun Ninja

lol

Alex M.

@almo thanks, but I asked already :(

Almo

heh ok

Noctrine

@ShotgunNinja No idea.

Shotgun Ninja

You and @KitFox both dropped in in the last half hour or so.

I was wondering if something got flagged.

KitFox

3:32 PM

Well, yes, but it was so fast, I think it must have been an accident.

Blue

I see that @PythonInProgress liked his hat.

KitFox

BTW, now we are exchanging yo mama jokes in the EL&U room.

in English Language & Usage, 26 mins ago, by Mr. Shiny and New 安宇

Yo mama so fat, wireless vendors had to release 802.11n before it was standardized by the IETF in order to download pictures of her.

Alex M.

lol

KitFox

in English Language & Usage, 1 min ago, by MετάEd

@Mr.ShinyandNew安宇 Yo mamma so fat, pictures of her broke TIFF compression scheme 6 (JPEG) so badly that it had to be replaced by scheme 7 (new JPEG). This is why HP multifunction printers can't scan her fat ass.

Shotgun Ninja

Nerdy Yo Mamma jokes.

KitFox

3:34 PM

Well, we are.

Speaking of, I have to go update my tables.

Later.

Almo

those are funny

Blue

"Yo mamma so fat, they had to invent 128 bit operating systems so they could address her waist size stored as an unsigned integer in memory."

Alex M.

guys, are you sure the legends about users who went to the cpp lounge, asked about objc and were never heard of again are true?

the place looks quite moderated

Shotgun Ninja

Go there and talk about how Java is better than C++.

Almo

hahaha

Shotgun Ninja

3:45 PM

Or how PHP is great because it's just like C++.

Alex M.

lol

Almo

I said I had a C question, though i was working in Obj-C and they deleted my chat messages.

Shotgun Ninja

Oh, that's perfect. Go ask them a question about C.

Almo

they were deleted inside about 15 sec

John McDonald

hahah

Impressive

:/ kinda odd though

Alex M.

3:51 PM

I'd honestly pay those $18 per year to get the vanillacodesnips.com when I get some content on

Blue

Or just come here and get real answers apply cold water to the burned area

Hey @ToddersLegrande - Nice hat

And Hey @JohnMcDonald @AlexM. and @Almo @Noctrine. @Gajoo my man. o/

Alex M.

hiya Blue

Almo

:)

Blue

slaps @AlexM. WHERE THE FUCK IS YOUR HAT!

>_<

Alex M.

I removed it, because you love Pip more than me!

Blue

3:59 PM

5 minutes, we'll fix that.

Shotgun Ninja

I love how his name has become Pip.

It's the perfect name for an enthusiastic 13-year-old on the internet.

Alex M.

ikr <3

Shotgun Ninja

en.wiktionary.org/wiki/millihelen

Blue

4:20 PM

@AlexM. Incredibly rough as I haven't got my mouse with me, but does this buy your love?

I'll try and make a better one later if you like.

Alex M.

I want a pretty hat

pip has a pretty hat, I want a prettier hat

Blue

You wanted a unicorn shaped star hat, so I made you one, that's a hat dontcha know.

Pip doesn't have a UNICORN shaped hat does he!

You do :D

;)

Alex M.

alright, I suppose you are right

Blue

Damn straight I'm right.

Alex M.

@TheProgramm3r ha, check out my hat!

okay @Blue, I love you again <3

Blue

4:24 PM

<3

And now I go home.

Alex M.

be safe dear :*

I tried the iOS MLP game today

I think it is the game with the most ways to get money out of your pocket in the world

Kikaimaru

what do you say on game name:
Bots on the XY Plane

Blue

Ttyl

Alex M.

I should have known since it starts out with a notification for parents

I hate this new thing

with actions taking X minutes to complete

but you can speed them up with money

John McDonald

@Kikaimaru Sounds robotic. And this is a bad time to use a pun because I'm trying to say the name could be more fun to read

Kikaimaru

4:32 PM

@JohnMcDonald they are on the XZ plane anyway

John McDonald

That they would be

And to answer your earlier question, if I had any issues with Awesomium 1.7.1: Not really. It's fast!

Kikaimaru

@JohnMcDonald i meant if there were complications in rewriting it for new version

John McDonald

Well... I did have 1 fun complication

Kikaimaru

and can you show me your surface?

but you are probably using SetData, right?

John McDonald

You used to be able to add global JS objects at any time, which makes sense because it's not specific to any one page. But now, you need some DOM (any DOM) to be loaded before you can create global JS objects. BUT my JS code relies on global JS objects to do stuff, so I had to work around that

@Kikaimaru Nope

Kikaimaru

4:37 PM

@JohnMcDonald i dont use (document).ready in awesomium i call my function pageLoaded from DocumentReady event - i dont know why i had to do this, but it stopped working at some point :)

John McDonald

See the Draw method here: bitbucket.org/mindworx/awesomiumxna/src/…

Kikaimaru

interesting

John McDonald

I use javascript's (read: jQuery's) onDomReady stuff so that I properly use my screens from any modern web browser

Kikaimaru

@JohnMcDonald i couldnt call c# method from document ready for some reason

but i can use any browser too, since i have document ready event with if !awesomium then pageLoaded

John McDonald

@Kikaimaru Because the globalJSObject isn't there yet

Alex M.

4:40 PM

4. is probably the most true

John McDonald

@Kikaimaru I actually wrote about my troubles, and solutions at length here: jcpmcdonald.com/index.php/80-blog/153-awesomium-xna-r2-released

Kikaimaru

@JohnMcDonald for the fonts you can just use black css shadow on white font, that looks good

John McDonald

Interesting... ok

And yeah, using that "RenderTexture2D" is much faster than the other methods. It's just an extension though which in turn does some... interesting things: bitbucket.org/mindworx/awesomiumxna/src/…

Well, I guess it really comes down to a D3DLOCKED_RECT and an unsafe buffer.CopyTo((IntPtr)(uint)(lockrect.pBits), lockrect.Pitch, 4, false, false);?

Alex M.

vanillacodesnips.wordpress.com

I'll stick to this theme for now

the only theme that I really liked costs $80

Code Assassin

@AlexM. good theme is good

Alex M.

4:50 PM

wish I could change that blue title to a black title

Kikaimaru

@JohnMcDonald thats similar of what im doing in sharpdx

Code Assassin

@AlexM. It may be possible

Alex M.

nah, it's not

I'm only stuck to wordpress' wizards

with $30/yr I can access some of the css and font settings

but I'm not sure what I can access exactly

Code Assassin

@AlexM. Dats some highway robbery right there.

Alex M.

ikr, you're better off with your own domain and hosting

but it gets more expensive

if you're okay with what themes you can find, and only want a domain name, for $18/yr it's a good deal to stick with wp.com

Code Assassin

4:54 PM

I'm on pins and needles with the results for the competition I competed in. I have a sick feeling in my stomach because I fear I did not even place(haven't even received one email and they say they are finalizing winners).

Alex M.

I know that feeling lol

Code Assassin

If the games the pick as winners are blatantly worse than mind I will probably be in depression. That means my assumption that it was a Good Old' Boys Network was correct.

Old boy network

An old boy network, or society (also old boys' club), can refer to social and business connections among former pupils of male-only private schools. British public school students were traditionally called "boys", thus graduated students are "old boys". This can apply to the network between the graduates of a single school, also known as an old boy society and similar to an alumni association. It can also mean a network of social and business connections among the alumni of various prestigious schools. In popular language, old boy network or old boy society has come to be used in referenc...

Alex M.

gotta take a shower, be back in a bit

Lounge<C++>

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