cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   criistii
   Member

   Hi.

   The last version of cocos2d introduced the concept of points (as opposed to pixels). This resulted in an inconsistency when developing a game for both iPad and iPhone, particles are to big and to fast on the iPhone if I design the particles for the iPad.

   Because of this I wrote a small utility method, and would love some feedback on this issue, or tips for a better approach:
   

   + (void) adjustParticlesForDevice:(CCParticleSystemQuad*)p {
   	CGFloat scale = IsIPad ? 1.0 : .5;
   
   	p.startSize = p.startSize * scale;
   	p.startSizeVar = p.startSizeVar * scale;
   	p.endSize = p.endSize * scale;
   	p.endSizeVar = p.endSizeVar * scale;
   	p.speed = p.speed * scale;
   	p.speedVar = p.speedVar * scale;
   	p.gravity = ccp(p.gravity.x * scale, p.gravity.y * scale);
   }

   UPDATE:
   After a bit more testing I noticed I need to update the life span as well, I find this very strange...
   

   p.life = p.life * scale;
   	p.lifeVar = p.lifeVar * scale;

   Posted 1 year ago #
2. 

   BigPapoo
   Member

   Hi,

   Just try this :
   

   p.scale = 0.5;

   Posted 1 year ago #
3. 

   BigPapoo
   Member

   Hi,

   In fact it's a bit more tricky. My previous suggestion doesn't work well in all cases.
   I finally patched the CCParticleSystem.m a bit and it works ok for me.
   To make a long story short, what you need to do is replace all CC_CONTENT_SCALE_FACTOR() calls in CCParticleSystem.m by KK_CONTENT_SCALE_FACTOR() for example. Now just create the KK_CONTENT_SCALE_FACTOR() like this :

   CGFloat KK_CONTENT_SCALE_FACTOR()
   {
   	if (_is_iPad_)
   		return 2.0;
   	else
   		return CC_CONTENT_SCALE_FACTOR();
   }

   What prevent the particle system from scaling well is that on iPad, the scale factor is 1.0 even if the screen size is closer to an iPhone 4 one. Note that _is_iPad_ is a global variable that I define at startup with this code (feel free to use any other way):
   

   _is_iPad_ = (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad);
   	if (!_is_iPad_)
   		_is_iPad_ = ([[[UIDevice currentDevice] model] rangeOfString:@"iPad"].location != NSNotFound);

   Posted 1 year ago #
4. 

   TBBle
   Moderator

   I'm a tad confused by your _is_iPad... Are you trying to make that true when you're running a non-iPad app on an iPad device?

   Posted 1 year ago #
5. 

   BigPapoo
   Member

   @TBBle :
   Sorry, I forgot to explain some points.
   First, I use this code for universal apps and it's ok in this only condition.

   The "_is_iPad_" is a global var that is initialized somewhere when starting my app (applicationDidFinishLaunching is a good place).
   It's a bit tricky but afaik it works correctly.
   But you should take care when running non-iPad apps on iPad. Non-iPad apps will set this flag ON, and that is not what you want to do of course as the iPad should be considered as an iPhone device in this case (just zooming @2x eventually)
   So if your app is not universal you have 2 options:
   1) your app is an iPad app, set "_is_iPad = YES" if you want or remove the test on _is_iPad var.
   2) your app is an iPhone app, set "_is_iPad = NO"...

   Hope this is clear enough and can help...

   Posted 1 year ago #
6. 

   TBBle
   Moderator

   That's exactly what I was asking you.

   Why isn't _is_iPad_ simply (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)? You've described precisely why you don't need the UIDevice check, as it's pointless in Universal mode, and dangerous for iPhone-only apps on an iPad.

   Posted 1 year ago #
7. 

   Herman
   Member

   To summarize what you need is:

   Change CC_CONTENT_SCALE_FACTOR calls to _CC_CONTENT_SCALE_FACTOR in CCParticleSystem.m

   static inline CGFloat _CC_CONTENT_SCALE_FACTOR()
   {
   	if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
   		return 2.0f;
   	else
   		return CC_CONTENT_SCALE_FACTOR();
   }

   Posted 3 months ago #

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