Saving game states etc.

iOS
#1

Is there a simple way to save game states/data on the iPhone - For instance if I want to start a game at a specific level after it has been restarted or save scores locally?

/Patrik

#2

cocoa does have an object for this that you can load your variables into and get them back when the application starts up, but since you’re using c++ likely that wouldnt be convenient.

for myself, i just use http://www.stfj.net/iPhone/ofxiPhoneFile-001.zip to write and read data to the phone. the idea would be to read in data when the application starts up if if that data exists, otherwise to write a default file. and then have some code in the exit() method in testApp.cpp that writes out the data you need to recover the gamestate to the file

#3

cocoa makes it really simple:
to load an int, you add for example in setup()

  
  
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];  
testInt = [defaults integerForKey:@"testInt"];

testInt is defined in .h file

to save it, you add, for example in touchDown():

  
  
testInt++;  
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];  
[defaults setInteger:testInt forKey:@"testInt"];

Both keys most be the same, but don’t have to be the name of the integer!

  
  
Floats:  
[defaults floatForKey:@"testFloat"];  
[defaults setFloat:testFloat forKey:@"testFloat"];  
  
Bools  
[defaults boolForKey:@"testBool"];  
[defaults setBool:testBool forKey:@"testBool"];

By the way: You have to rename testApp.cpp to testApp.mm, because you are mixing obj-c with c++ here.

Regards,
Gestalt

#4

touché!

thats awesome

#5

Thanks guys, just what I was looking for.

/P

#6

Hi

I am using the cocoa code for an iphone app and it saves my values nicely. but only if i quit the app via the home button.

if i quit the app with:

std::exit(0)

or

[[UIApplication sharedApplication] terminateWithSuccess];

the values are not saved, even though the saving happens during touchUp.

any ideas?

thanks,
stephan.

#7

ok i think i found a solution:

after saving the values add [[NSUserDefaults standardUserDefaults] synchronize];

like this

  
  
testInt++;  
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];  
[defaults setInteger:testInt forKey:@"testInt"];  
[[NSUserDefaults standardUserDefaults] synchronize];

so when i now quit the app with a exit button/ command the values are being remembered.

cheers,
stephan.

#8

Hi, I hope I’m not too late but… does anyone have an example of saving to a text file in the ios documents folder? I want to be able to see the created file.

Thanks.

#9

trentbrooks, the XMLSettings example should be sufficient for showing how to save to a text file in the documents folder.

#10

Thanks Seth, i dug through the xmlsettings and found what I needed but finally settled on this instead:

// create or open a file
string filename = “myfile.txt”;
File pFile = fopen((ofxiPhoneGetDocumentsDirectory() + filename).c_str(),“w”);

// add some lines of text
string line = “saving some data \n”;
fputs (line.c_str(),pFile);

// save file
fclose (pFile);