A fast, easy to use, free, and community supported 2D game engine
indy2005
Member
Hi,
Noob question. I am working through AtlasSprites....you create a manager, add the manager to the scene or layer, and then add sprites to the manager.
When you are setting the position of the AtlasSprites - is the position being set relative to the layer the manager was added to - or to the manager itself (which is a subclass of CocosNode so I am guessing can have a position?)...
Thanks
i
Scene
Layers
SpriteManagers
Sprites
All Nodes relative to the CocosNode they were added to, and subsequently up the chain. For example, you could change the position of a sprite, and it's manager/layer/scene would not change.
If, however, you moved a Layer containing a sprite, the layer and all the nodes it contains would be moved relative to how the layer moved.
To answer your question, moving a sprite would be moving it relative to the manager it was added to.
This is my understanding, anyways.
Oh what I would pay for a good book on Cocos2d!
indy2005
Member
Hi,
Thanks. Where would the mystery be if it was all laid out in a book. My mum would be writing games then ;-)
In all the samples I see for AtltasSpriteManager, the manager is added to the layer, and then sprites are added to the manager. The sprites are positioned - but I never see the manager getting positioned. I am assuming the sprites get positioned within the manager - but why does the manager never get positioned!
Also, managers always seem to get added with a zindex. If you have multiple managers in a layer with different z indexes, and different sprites in each manager with separate z-indexes....how does that work?
Thanks
i
"... and I'd pay DOUBLE that for a good book on Cocos2d/Box2d!"
Make it TRIPLE if it explained the physics math in layman's terms for people like me :P
Indy 2005,
You can change the position of the sprite manager, and it will in turn change the position on all the children it contains (which can only be atlas sprites now).
I hardly ever use z ordering because I don't have a need for it just yet. It allows one manager (or layer, sprite, etc) to be ordered in front or in back of another. I usually create all my objects before displaying the scene and avoid creating new objects mid-game. It can lead to jerky frame rates.
You can add nodes in the order you want them to be in. But if you needed to create a new sprite/manager/etc mid-game you could use the z order to 'insert' a node - kind of like inserting it into an array at a specific position, and bumping the rest of the (nodes) down one.
indy2005
Member
Hi,
Thanks. I am just trying to understand why in all the samples, the sprites are positioned within the manager, but there is never a positioning of the manager itself..
#pragma mark Example Atlas 1
@implementation Atlas1
-(id) init
{
if( (self=[super init]) ) {
self.isTouchEnabled = YES;
AtlasSpriteManager *mgr = [AtlasSpriteManager spriteManagerWithFile:@"grossini_dance_atlas.png" capacity:50];
[self addChild:mgr z:0 tag:kTagSpriteManager];
CGSize s = [[Director sharedDirector] winSize];
[self addNewSpriteWithCoords:ccp(s.width/2, s.height/2)];
}
return self;
}
-(void) addNewSpriteWithCoords:(CGPoint)p
{
AtlasSpriteManager *mgr = (AtlasSpriteManager*) [self getChildByTag:kTagSpriteManager];
int idx = CCRANDOM_0_1() * 1400 / 100;
int x = (idx%5) * 85;
int y = (idx/5) * 121;
AtlasSprite *sprite = [AtlasSprite spriteWithRect:CGRectMake(x,y,85,121) spriteManager:mgr];
[mgr addChild:sprite];
sprite.position = ccp( p.x, p.y);
id action;
float rand = CCRANDOM_0_1();
if( rand < 0.20 )
action = [ScaleBy actionWithDuration:3 scale:2];
else if(rand < 0.40)
action = [RotateBy actionWithDuration:3 angle:360];
else if( rand < 0.60)
action = [Blink actionWithDuration:1 blinks:3];
else if( rand < 0.8 )
action = [TintBy actionWithDuration:2 red:0 green:-255 blue:-255];
else
action = [FadeOut actionWithDuration:2];
id action_back = [action reverse];
id seq = [Sequence actions:action, action_back, nil];
[sprite runAction: [RepeatForever actionWithAction:seq]];
}Notice the positionng of AtlasSprites, but the AtlasSpriteManager is only added with a index, and the position is never set. This is why thought the sprites are actually being positioned in the Managers "parent" rather than the manager itself.
hope the question makes sense!
i
"...the sprites are actually being positioned in the Managers "parent" rather than the manager itself."
Are they? It may be so, but I haven't noticed the manager working that way (I could be mistaken).
Try this. Make a test app (as I often do) where you can try out things. Add a scene with a single layer. In the layer, add a manager and add a sprite to it.
From the layer, use a scheduler to move (setPosition) manager. While moving the manager, nslog the position of the layer. Don't forget to post the result!
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