Monthly Archive for March, 2009

Hey,
cocos2d v0.7.1 is available for download.

Download:
http://cocos2d-iphone.googlecode.com/files/cocos2d-iphone-0.7.1.tar.gz

Highlights:

• Sprite Sheets (For further info please read this post: spritesheet-in-v071 )
• Local to World coordinates and vice-versa
• Sound Support (warning: experimental feature)

Compatibility:
cocos2d v0.7.1 is 90% compatible with v0.7.0. You need to add new files and
you might need to add some linker parameter. Also some selectors were deprecated.
Please, read CAREFULLY the following instructions:

• INSTRUCTIONS to migrate from v0.7.0 to v0.7.1

Full Changelog:

• Actions: added tags to actions (issue #222)
• Actions: Spawns can be Speeded (issue #257)
• Actions: Speed can be altered in runtime (part of issue #236)
• AtlasSprite: Sprite sheet implementation (issue #238)
• Chipmunk: cpVect is defined as a CGPoint (issue #260)
• CocosNode: Camera is lazy alloced (issue #94)
• CocosNode: addChild, removeChild:cleanup, getChildByTag family functions (issue #253)
• CocosNode: added better comments, cleanup code (issue #219)
• CocosNode: added RGB protocol: Atlas,Texture & ColorLayer conforms it (issue #234)
• CocosNode: fixed memory leak when removeAndStop a node with children with actions (issue #254)
• CocosNode: added transform local to world coordinates that support rotation,scale & position (issue #207)
• CocosNode: removed scale ivar (issue #231)
• CocosNode: improved handling of nil parameters (issue #262)
• CocosLive: filter by device id (issue #223)
• CocosLive: category is UTF8′ized (issue #227)
• CocosLive: using cc_playername instead of usr_playername (issue #242)
• CocosLive: supports “update score” (issue #250)
• Demos: added performance test (issue #243)
• Director: FastDirector doesn’t leak autoreleased objects (issue #221)
• Director: prevents calling startAnimation twice in a row (issue #215)
• Menu: can be aligned in columns / rows. Updated menu example (issue #206)
• Menu: MenuItem supports LabelAtlas (issue #235)
• Menu: MenuItemFont fixed memory leak (issue #232)
• Menu: MenuItem improved hit testing (issue #214)
• Scheduler: if signature is not correct Assert (issue #218)
• Sprite: correct transform anchor point (issue #216)
• TextureAtlas: support for texture2D (issue #161)
• Tools: Added perf-test results (issue #243)

As always, big thanks to the community for adding new features, fixing bugs, submitting patches, opening issues, testing the release candidate, etc!!

Chipmunk has a type called cpVect that is used to define a vector.
The above mentioned structure is defined as:

typedef struct cpVect{ cpFloat x,y;} cpVect;

On the other hand, CoreGraphics has a similar type called CGPoint that is defined as:

struct CGPoint {CGFloat x;CGFloat y;};typedef struct CGPoint CGPoint;

These 2 types has the same attributes (they are identical) but they aren’t interchangeable because they are different types.
You can’t do add a CGPoint with a cpVect, neither you can’t test whether or not a cpVect is inside a CGRect, etc.

Since cocos2d v0.7.1 you will be able to mix them and use them interchangeably. The solution was a simple hack:

// file cpVect.h

#import <CoreGraphics/CGGeometry.h>#define cpVect CGPoint//typedef struct cpVect{// cpFloat x,y;//} cpVect;

cocos2d v0.7.1 supports SpriteSheets. An SpriteSheet basically is an image that contains subimages, and these subimages can be used as sprites. In cocos2d v0.7.1 these new sprites are called AtlasSprite.

These are the benefits of using AtlasSprite instead of the normal Sprite:

• Reduces texture memory since all the sprites are in one big image.
• Reduces render time since there are less OpenGL calls. The new order is O(1) while the order of using normal Sprites is O(n). If you have 400 AtlasSprites, now you have to do 6 OpenGL calls. With 400 Sprites you have to do 400 *6 OpenGL calls.

How do you use it?:

// Create the AtlasSpriteManager
// You can use a .PNG file or a PVRTC image.
// capacity is an optional parameter. It is just a hint that means the quantity of total sprites.
// You can add more (or less) sprites than the quantity.
// grossini_dance_atlas.png is an image than contains the subsprites.
AtlasSpriteManager *mgr = [AtlasSpriteManager spriteManagerWithFile:@"grossini_dance_atlas.png" capacity:50];
 
// You create the sprite
AtlasSprite *sprite = [AtlasSprite spriteWithRect:CGRectMake(x,y,85,121) spriteManager:mgr];
 
// you add the sprite to the parent
// the parent must be the AtlasSpriteManager
// z must be 0.
// You can add tags if you want.
[mgr addChild:sprite z:0 tag:kTagSprite1];
 
// you can transform the sprite
sprite.position = cpv( 200,300 );
sprite.rotation = 90;
sprite.scale = 2.0f;
 
// you can run actions in this new sprite
[sprite runAction: [RotateBy actionWithDuration:2 angle:360]];

The TestAtlas.m file (Example #5) contains a working example of AtlasSprite.
The PerformanceTest example compares Sprite vs AtlasSprite performance (more on this later).

cocos2d v0.7.1 supports SpriteSheets. An SpriteSheet basically is an image that contains subimages, and these subimages can be used as sprites. In cocos2d v0.7.1 these new sprites are called AtlasSprite.

These are the benefits of using AtlasSprite instead of the normal Sprite:

• Reduces texture memory since all the sprites are in one big image.
• Reduces render time since there are less OpenGL calls. The new order is O(1) while the order of using normal Sprites is O(n). If you have 400 AtlasSprites, now you have to do 6 OpenGL calls. With 400 Sprites you have to do 400 *6 OpenGL calls.

How do you use it?:

// Create the AtlasSpriteManager// You can use a .PNG file or a PVRTC image.// capacity is an optional parameter. It is just a hint that means the quantity of total sprites.// You can add more (or less) sprites than the quantity.// grossini_dance_atlas.png is an image than contains the subsprites.AtlasSpriteManager *mgr = [AtlasSpriteManager spriteManagerWithFile:@"grossini_dance_atlas.png" capacity:50];

// You create the spriteAtlasSprite *sprite = [AtlasSprite spriteWithRect:CGRectMake(x,y,85,121) spriteManager:mgr];

// you add the sprite to the parent// the parent must be the AtlasSpriteManager// z must be 0.// You can add tags if you want.[mgr addChild:sprite z:0 tag:kTagSprite1];

// you can transform the spritesprite.position = cpv( 200,300 );sprite.rotation = 90;sprite.scale = 2.0f;

// you can run actions in this new sprite[sprite runAction: [RotateBy actionWithDuration:2 angle:360]];

The TestAtlas.m file (Example #5) contains a working example of AtlasSprite.
The PerformanceTest example compares Sprite vs AtlasSprite performance (more on this later).