How To Add Box2d to an xCode Project

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How To Add Box2d to an xCode Project

(34 posts) (17 voices)

Started 2 years ago by shivaz
Latest reply from jules_s

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shivaz
Member

Just going through the process of adding Box2d to my game, and have been struggling with getting it to compile. Tried all sorts of things, from hacking back the cocos2d svn test - to try and get an project that works. But no real success :P

Until I found this blog article: http://blog.zincroe.com/2009/05/how-to-add-box2d-to-an-iphone-xcode-project/

The big trick is renaming all your .m files to .mm - if they include any file that includes box2d (safest to do all).

You might then run into an error about malloc (if you use it like I did) - which is fixable here http://cboard.cprogramming.com/c-programming/96593-program-compile-help.html

Also if you use the latest svn of box2d - you might get an issue about it not finding all its include files? Well, you then need to "target->info->build" and add a header search path - and tick always search user paths.

Hope that helps someone! Really looking forward to getting my hands dirty with Box2d and see what wonders it will bring to my game over Chipmunk.

Justin

Posted 2 years ago #
smooth
Member

haha you were right, seting file type from c.objc to cpp.objcpp did the trick. I had like 600 errors before fixing and i lost like 3 hours figuring what is wrong.

thnx man!

Posted 2 years ago #
Codemattic
Moderator

I havent used box2d yet - but I plan to - so thanks for the tips!

Posted 2 years ago #
shivaz
Member

@smooth, no worries - only lost 3 hours? :P Feels like I lost days!

Posted 2 years ago #
cjl
Member

For future reference of people searching the forum, and my own failed memory, the header search path can bet set to '.' (without the single quotes, just a dot)

I'm not sure if there's a better setting, but '.' worked for me.

Posted 2 years ago #
kenny
Member

Hi!!

I am still having issues trying to compile with box2d. I followed directions above from Justin but still getting 3K+ errors (e.g. Box2D/Common/b2Settings.h:No such file or directory)??? What should I add to "header search path"???

I am using cocos2d 0.8.1.

Thanks,

Kenny

Posted 2 years ago #
cjl
Member

@lmrkllc

I was getting the same number of errors, before I updated the header search path. Here's what I did:

1) Started a new project using the template included with Cocos2d, which can be installed with the shell script.
2) Added Box2d to my project from the external directory in the Cocos2d download, using the "copy" option. Don't add the entire Box2d download, add the subdirectory containing the source only.
3) Goto the build info for your project's target, and add a recursive header search path. I used a single dot, which resolves to something like './'

Anyway, that's what worked for me.
Be aware that the version of Box2d included with Cocos2d is newer than the latest release, and there are significant API changes.

Posted 2 years ago #
kenny
Member

@cjl

YYEESSS!!! THANKS!!!! Only have 8 errors now!!! :-)

I guess I am missing something with GLES-Render.h: No such file or directory??

It was step 2 (I did NOT use "copy").

I also have 112 Warnings even though I have GCC_TREAT_WARNINGS_AS_ERRORS=NO.

Thanks Again,

Kenny

Posted 2 years ago #
riq
Key Master

GLES-Render.h and .cpp are located in tests/Box2dTestBed-CocosIntegration/ (v0.8.1)
copy from there to your project.

Posted 2 years ago #
steve
Member

Riq,

Perhaps there could be a template for cocos2d with box2d.

Posted 2 years ago #
tjweir
Member

@steve - I'm working on one, http://github.com/tjweir/iphone-cocos2d-box2d/tree/master

There's nothing there yet due to a 20-day old daughter :)

But I'm working on it when I can.

Posted 2 years ago #
cjl
Member

I just updated the Box2D 'Hello World' ball with gravity example to run with Cocos2d 0.8.1, so I can post it somewhere if others are interested.

In a weird way, the examples in the test bed seem to advanced for newbies like me.

I'm upgrading to Snow Leopard today, so I might not be able to post the code until later, but let me know if you're interested.

Posted 2 years ago #
kenny
Member

Thanks all!!!

-Kenny

Posted 2 years ago #
jo
Member

@cjl - Can you please post the steps to Configure Box2D with Cocos2d 0.8.1? I spent 2 days on this, and now am going back to Cocos2d 0.8 (Chipmunk integrated)

Posted 2 years ago #
steve
Member

@jo, I'm trying to get it going as well. A number of the method signatures of Box2D have changed, so if you are trying to use old (i.e., cocos2d 0.8) Box2D code that could cause the problem.

@tjweir, I appreciate your efforts, but IMO it would be best to have the template in the cocos2d tree so you and the rest of us aren't playing catch-up with riq each release.

Posted 2 years ago #
steve
Member

IIRC, here's what finally worked for me:

1) Load cocos2d-iphone.xcodeproj so cocos2d is in XCode. (This may not be necessary.)

2) Run the install_template.sh so there is a cocos2d-0.8.1 application template.

3) Use that template to create a new project.

4) In the new project, under Other Sources, bring up the context menu Add > Existing files... and add the Box2D directory (Location: cocos2d-iphone-0.8.1/external/Box2d/Box2D).

5) In the new project, under Other Sources, bring up the context menu Add > Existing files... and add GLES-Render.h and GLES-Render.mm (Location: cocos2d-iphone-0.8.1/tests/Box2DTestBed-Cocos2dIntegration).

6) Select your project from the Groups & Files list on the left hand side. Click the blue Info button on the top center of the window. Select build from the top tabs (right under Project "yourprojectname" Info). Scroll down to Search Paths Edit Header Search Paths. To quote cjl, "[...] add a recursive header search path. I used a single dot, which resolves to something like './'"

7) Change your projectnameAppDelegate.m to projectnameAppDelegate.mm .

You should now be able to add Box2D elements to your game. Again, be aware that the methods of the Box2D in cocos2d 0.8.1 can be different than what was in cocos2d 0.8.0 or on sites around the web. Check out the Box2D examples in cocos2d 0.8.1 for the correct signatures.

Thanks for all the previous comments which helped me get a working project.

Steve

Posted 2 years ago #
allenfjordan
Member

Following the advice in this post, I've narrowed my Box2D warnings down to 3. One trick (found somewhere on google) was to change b2Settings.h to have:

//#define B2_NOT_USED(x) x //this was the old line
#define B2_NOT_USED(x) (void)(x) //new line that fixes warnings

The warnings I'm still getting are:

/Users/blahblahblah/Documents/Box2d Test/Box2dTest/Box2D/Collision/b2Distance.cpp:70: warning: comparison is always true due to limited range of data type

The problem is with this line (extra parens added by me):
b2Assert((0 <= cache->count) && (cache->count <= 3));
but it looks like count is a "uint16," which should have a decent data range, so I don't know.

The other two warnings are in b2World.cpp, and have to do with enumeration values not being handled in a switch (not a big deal, I imagine, but the warnings still bother me).

Posted 2 years ago #
atze
Member

The compiler does not state that the whole
(0 <= cache->count && cache->count <= 3)
is true :)
Only
0 <= cache->count
is always true for an uint16 (and in fact any unsigned value). Just remove it.

For the switch just add a
default:break;
at the end and the warning disappears.

Posted 2 years ago #
eshirt
Member

@steve

I followed your steps word for word, then I build my project and I am still getting 3000+ errors.

error:Box2D/Common/b2Settings.h: No such file or directory
and on and on

Am I missing a step, an #import, or something?

Running Cocos2d 0.8.1

Posted 2 years ago #
eshirt
Member

Ha, of course, right after I post my question, I find my mistake.

I had edited Search Paths > User Header Search Paths

As soon as I edited Search Paths > Header Search Paths, it got rid of all the warnings.

I also had to add the same properties to the Target, not just the Xcode project in the Groups & Files panel.

Now I have 112 warnings - all related to the Box2D ccp files:

warning: statement has no effect.

What's missing here?

Posted 2 years ago #
eshirt
Member

Looks like my errors were the same as allanfjordan's. Using his modified b2settings.h, I got my errors down to one.

Thanks to atze for the help getting those last ones removed.

I just commented out the line:

b2Assert(0 <= cache->count && cache->count <= 3);

It's not giving me any warnings now, but is that safe?

Posted 2 years ago #
Lam
Member

don't comment out the last line!!
just use b2Assert(cache->count <= 3);

It's really warning you that an unsigned int 'cache->count' (which is positive) can never be less than zero so 0 <= cache->count is always true and redundant.

That's pretty much what I did :)

Posted 2 years ago #
kenny
Member

@cjl - Please let me know if you have posted the Box2D 'Hello World' ball with gravity example to run with Cocos2d 0.8.?? If so, please let me know where??

Thanks Again,

Kenny

Posted 2 years ago #
cjl
Member

@kenny:

Sorry, my 'real job' and my 'real life' conspired against me the last few weeks, so I haven't had a chance to upload it somewhere.

I'll probably have a chance in the next day or so, and I'll update this thread when I do.

Posted 2 years ago #
onedayitwillmake
Member

I posted a zip with cocos2D 8.1 with box2d based on the cocos2d 8.1 template in a different forum post yesterday if anyone is interested.

http://www.cocos2d-iphone.org/forum/topic/1898

Posted 2 years ago #
onedayitwillmake
Member

Actually, I appologize.
While I was able to get it to compile without warning with Box2D in the directories, once I tried to include it - i got tons of all new errors.

Posted 2 years ago #
kenny
Member

@cjl - LOL!! Understood!!! my apologies!! No rush!! thanks for the update!!!

Posted 2 years ago #
onedayitwillmake
Member

Alright, I found the problem once again!
So I got it working!

In this project you will find:
Cocos2d 8.1 working with Box2d
Box2D world created on init
AtlasSpriteManager created to manage the sprites
Circles falling from the sky and stacking on top of one another.

also:
schedule function that creates a different colored ball randomly and adds it to the world
a different colored ball is created and placed in the scene when the screen is touched at the touch location.

http://onedayitiwillmake.com/box2dcocos2d.zip

(Link fixed thanks babyfish)

Posted 2 years ago #
babyfish0226
Member

http://onedayitiwllmake.com/box2dcocos2d.zip is Dead link.
The corrent link is http://onedayitwillmake.com/box2dcocos2d.zip

And ... i can't open this project because it show the error of "missing project.pbxproj file".

Posted 2 years ago #
onedayitwillmake
Member

Ok I'll check it out babyfish0226.

One thing that I did was disable the build folder from SVN, because it's such a nightmare to manage once things change.
I'm very new to all of this myself, and been messing with objective-c/cocos2d for 2 weeks so, please feel free to point out any mistakes / or better practices.

I'll check look into that, i think i'll just place the ./build folder, inside the zip file.

Posted 2 years ago #

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