CCFollow does not stopping following - cocos2d-iphone

Hi this is my first question in cocos2d!
I am using this code to follow the ball :
[self runAction:[CCFollow actionWithTarget:ball]];
i need a code the action will be stopped before we can see a black background...
Sorry for the bad english!!

You need to set the world boundary of the follow, which will constrain the follow to the defined rect:
[self runAction:[CCFollow actionWithTarget:ball worldBoundary:CGRectMake(0,0,WINWIDTH,WINHEIGHT)]];

Related

Understanding cocos2d scenes, how they works really?

I'm stuck on something about the scenes creation and replacement in cocos2d, so I'm going to ask precisely what seems to be misunderstood by me. I have a game (fully working except for scene swapping, sadly) with some little-games, now, if I had to do this starting with a cocos2d scene as menu I wouldn't have any problem, but since I did it starting with UIKit I truly need to know better how the scenes are working to fix it.
Firstly, is it required to start a scene in the appDelegate? since I'm starting with UIkit and the scene must be shown after you choice the game (say, out of 3 choices), which scene should I put in the appDelegate? and where exactly? I'm putting the scene in this method:
-(void) directorDidReshapeProjection:(CCDirector*)director
{
if(director.runningScene == nil)
//start scene
}
If I put the FIRST scene, the UIKit part works good and when I start the "game number TWO" as first choice (say we play this game for first) I got the Open GL 0x0506 error, then the scene start.
If I put the first scene, I choice the first game, and then quit and choice the second game, the scene is replaced properly without that error.
If I put the first scene, and I start the "game number 1" it works (obviously) because he has the scene loaded, but I cannot know which game will start as first the user.
I tried with an "intro scene" loaded at the appDelegate but I got the same problem. the problem basically is "how to start scene if you have more than one scene and don't know which will be called as first"...
The 'getting started with iOS' documentation will really clear up a lot of these questions. You can find it at developer.apple.com - https://developer.apple.com/library/ios/#documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40007072
It explains just what an AppDelegate actually is, as well as how to use one properly. It is not immediately clear how to mix UIKit and cocos2d, but the above link cleared a lot up for me. Another very helpful resource is a tutorial by Ray Wenderlich -
http://www.raywenderlich.com/4817/how-to-integrate-cocos2d-and-uikit
From a bird's eye view, the CCDirector inherits from a UIWindow. Mixing UIKit and cocos2d is as simple as building your interface with UIKit, then at some point opening a UIWindow and allowing the CCDirector to start cocos2d. In a sense, the components act as almost two entirely separate entities.

Scrolling Background with Cocos2D and Box2D

I am trying to create a simple game that mainly consists of a ball rolling down an incline. The player's only control is to cause the ball to jump. My question is, what is the best way to make it appear to roll while generally keeping the ball at the same place on the screen? I have considered CCCamera, but it seems like it's not the best option since I want a repeating background image. Scrolling the background manually is also giving me trouble because it's not clear how to get the ball to stay in one place while letting Box2D handle the physics. I'd appreciate any help as I've been stuck on this for quite a while.
Use CCFollow on the layer where you draw the game stuff, and let it follow the ball sprite:
[gameLayer runAction:[CCFollow actionWithTarget:ball]];

How To Retrieve Actions From Sprite In cocos2d

I have a CCSprite that I'm using in a scene and have created multiple CCAnimation actions to apply to it all using a single CCSpriteFrameCache sharedSpriteFrameCache. While everything is working and I'm able to switch between animations, I feel like I'm doing poorly and would like to simplify my code by retrieving the running action(s) on the CCSprite to stop them individually before running the next action on it.
To help create some context, lets assume the following situation:
We have a CCSprite called mySprite
We have 3 separate CCAnimation actions defined for walking to the right, walking to the left, and sitting looking forward called: actionAnimWalkRight, actionAnimWalkLeft, and actionAnimSitForward respectively.
We want to have the sprite walk to the right when someone touches the screen right of mySprite, walk left when someone touches the screen left of mySprite and sit when someone touches mySprite.
The approach I'm using to accomplish this is as follows:
Place CCSprite as a child in the scene.
Tell the sprite to run an action using: [self runAction:actionWalkRight];
When I want to change the action after someone touches, I have a method called stopAllAnimationActions which I call before I apply a new action that stops any animation action no matter what's running. Basically lists ALL the CCAnimation/CCActions I have defined and stops each one individually since I don't want to use stopAllActions. as follows: [self stopAction:actionWalkRight]; [self stopAction:actionWalkLeft]; [self stopAction:actionSitForward];
Then I apply the new animation after the above method fires using: [self runAction:actionWalkLeft];
While this works, it just seems like a poor design to stop items that I know aren't running just because I don't know exactly what is running. So just looking for advice and the best recommended practice to do something like this within very complex situations so tracking every possible situation is difficult. Any feedback would be appreciated.
When creating the actions set the tag of that action with a constant:
actionWalkRight.tag= kCurrentAction;
[self runAction:actionWalkRight];
Then, retrieve the running action by that tag and stop it.
[self stopActionByTag:kCurrentAction];
I recommend you simplify your process and take advantage of the native Cocos features, including stopAllActions. Don't re-use actions, always create them from scratch as it has been well discussed among Cocos developers that re-using actions can be buggy.
Cocos is well optimized and features like stopAllActions are not performance hogs. It would probably be faster than your approach, actually.

Cocos2D - Particles follow the emitter instead of staying at the position they were released

In cocos2D I currently have a very simple particle emitter initialized like this:
turnEmitter = [[CCParticleFlower alloc] init];
turnEmitter.texture = [[CCTextureCache sharedTextureCache] addImage:#"Pocket.png"];
[self addChild:turnEmitter z:1];
turnEmitter.scale = 0.7f;
turnEmitter.positionType = kCCPositionTypeFree;
It is simply added directly to the gameplay layer.
This emitter follows a sprite around the screen in this way (happens in the update method):
turnEmitter.position = turnEmblem.position;
Now the problem is that the tail of particles left behind the emitter moves with the emitter, instead of released particles simply staying in the position they were released, which gives a really weird and stupid looking effect.
What I want to do is have the particles not follow the emitter at all after they have been spawned, unfortunately I have been unable to find any way of doing so.
As you can see from the code above I have already searched around, and found people which suggests changing the positionType property of the emitter, although I have tried all the possibilities and it does not solve the problem.
Does anyone have any ideas as to what this might be?
You may want to try changing the "emitterMode" as well to "kCCPositionTypeFree". I had a similar issue where i had the emitter as a child of a CCNode. The CCNode was being rotated, but the particles and emitter wasn't. In the same way it looked stupid because the illusion of rotation was ruined. I need to set the following on my emitter:
emitter.emitterMode = kCCPositionTypeRelative;
emitter.positionType = kCCPositionTypeRelative;

Coloring application using Cocos2D

I trying to make an empty CCSprite then I want to hand drawing on it using touch controls.
But, I don't have an idea how make it and don't know it's possible.
So, PLS help me or give me some advice.
Thanks
I wrote a demo program for CCRenderTexture which shows you how to draw sprites (or whatever you want) with touches:
Hi You can use CCRenderTexture example from Cocos2d for drawing..
Check out this link http://www.cocos2d-iphone.org/forum/topic/8474