1 Hello, Cocos2D ——《Learning Cocos2D》

前段时间粗略看完《Learn cocos2D Game Development with iOS 5》，作者之一是kobold2d（http://www.kobold2d.com/，很棒的一个开源框架，封装了cocos2d，提供众多的模版，省去大量配置的时间，所有东西都在一个盒子里面，想用什么拿出来就可以使用，非常强大和易用）开源框架的作者Steffen，这本书每一章用一个小游戏来介绍cocos2d的特性，涉及到cocos2d的方方面面，但是章节之间相对独立。看过之后，感觉是知道有这些特性，以后要用到的话再看看也可以拿过来使用，但是对一个完整游戏还是缺乏清晰的认识。

现在打算开始看《Learning Cocos2D》，书其中一个作者是ray wenderlich（http://www.raywenderlich.com/，里面的ios游戏和应用开发教程超一流）。相对而言，这本书介绍了如何使用cocos2d开发一个完整的游戏的过程。这样的话，透过这本书，一方面可以复习一下cocos2d，另一方面可以学习开发一个完整cocos2d游戏。

现在打算把一些关键的地方和一些想法记录下来，一方面可以放慢学习的速度腾出时间来思考练习，另一方面方便以后的翻查。翻滚吧，第一章的记录：

1 CCDirector控制场景切换，它是整个游戏的导演，这只是它其中的一个职责。

2 Cocos2D层次结构，很清晰

ControlsLayer支持触摸事件，点击屏幕，在ControlsLayer的ccTouchEnded里面，

a）获取MainLayer，CCNode *layer = [[CCDirectorsharedDirector].runningScenegetChildByTag:MainLayerTag];

b）然后获取MainLayer的label，CCNode *label = [layergetChildByTag:MainLayerLabelTag];

c）最后[label runAction:sequence];

这样就实现了在ControlsLayer里面控制MainLayer的Sprite。

代码如下，

#ifndef CCHelloWorld_Constants_h
#define CCHelloWorld_Constants_h

#define MainLayerLabelTag 0

enum {
    BackgroundLayerTag,
    MainLayerTag,
    ControlsLayerTag,
    TagMax
}layerTag;

#endif

#import <Foundation/Foundation.h>
#import "cocos2d.h"

@interface BackgroundLayer : CCLayer {
    
}

@end
#import "BackgroundLayer.h"

@implementation BackgroundLayer

- (id)init {
    if (self = [super init]) {
        CCLabelTTF *label = [CCLabelTTF labelWithString:@"I am background layer" fontName:@"Marker Felt" fontSize:96];
        CGSize winSize = [[CCDirector sharedDirector] winSize];
        label.position = ccp(winSize.width/2, winSize.height/2);
        label.color = ccWHITE;
        [self addChild:label];
    }
    return self;
}

@end
#import <Foundation/Foundation.h>
#import "cocos2d.h"

@interface MainLayer : CCLayer {

}

@end
#import "MainLayer.h"
#import "Constants.h"

@implementation MainLayer

- (id)init {
    CCLOG(@"%@ init", NSStringFromClass([self class]));
    if (self = [super init]) {
        CCLabelTTF *label = [CCLabelTTF labelWithString:@"I am main layer" fontName:@"Marker Felt" fontSize:64];
        CGSize winSize = [[CCDirector sharedDirector] winSize];
        label.position = ccp(winSize.width/2, winSize.height/2);
        label.color = ccGREEN;
        [self addChild:label z:0 tag:MainLayerLabelTag];
    }
    return self;
}

@end
#import <Foundation/Foundation.h>
#import "cocos2d.h"

@interface ControlsLayer : CCLayer {
    
}

@end
#import "ControlsLayer.h"
#import "Constants.h"

@implementation ControlsLayer
- (id)init {
    if (self = [super init]) {
        self.isTouchEnabled = YES;
        CCLabelTTF *label = [CCLabelTTF labelWithString:@"I am controls layer" fontName:@"Marker Felt" fontSize:32];
        CGSize winSize = [[CCDirector sharedDirector] winSize];
        label.position = ccp(winSize.width/2, winSize.height/2);
        label.color = ccBLACK;
        [self addChild:label];
    }
    return self;
}

- (void)registerWithTouchDispatcher {
    [[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:0 swallowsTouches:YES];
}

- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event {
    return YES;
}

- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event {
    CCLOG(@"%@ ccTouchEnded", NSStringFromClass([self class]));
    CCNode *layer = [[CCDirector sharedDirector].runningScene getChildByTag:MainLayerTag];
    CCNode *label = [layer getChildByTag:MainLayerLabelTag];
    CGSize winSize = [[CCDirector sharedDirector] winSize];
    CCMoveTo *moveTo = [CCMoveTo actionWithDuration:1.0f position:ccp(50, 50)];
    CCMoveTo *moveBack = [CCMoveTo actionWithDuration:1.0f position:ccp(winSize.width/2,winSize.height/2)];
    CCSequence *sequence = [CCSequence actions:moveTo, moveBack, nil];
    [label runAction:sequence];
    [label runAction:[CCFadeOut actionWithDuration:4.0f]];
}

@end
#import <Foundation/Foundation.h>

@interface Level_1 : NSObject
+ (id)scene;
@end
#import "Level_1.h"
#import "BackgroundLayer.h"
#import "MainLayer.h"
#import "ControlsLayer.h"
#import "Constants.h"

@implementation Level_1
+ (id)scene {
    CCLOG(@"%@ scene", NSStringFromClass([self class]));
    CCScene *scene = [CCScene node];
    MainLayer *mainLayer = [MainLayer node];
    BackgroundLayer *backgroundLayer = [BackgroundLayer node];
    ControlsLayer *controlsLayer = [ControlsLayer node];
    [scene addChild:backgroundLayer z:-1 tag:BackgroundLayerTag];
    [scene addChild:mainLayer z:0 tag:MainLayerTag];
    [scene addChild:controlsLayer z:1 tag:ControlsLayerTag];
    return scene;
}
@end

3 more than ‘Hello World’

a）触摸炸开‘Hello World’，以字母为单位分裂

使用CCLabelBMFont，每一个字符都可以像CCSprite那么操作，旋转、缩放、着色等，参考cocos2d-iphone里面的测试项目LabelTest类Atlas4的实现

#import "cocos2d.h"

// HelloWorldLayer
@interface HelloWorldLayer : CCLayer
{
}
+(CCScene *) scene;

@end
// Import the interfaces
#import "HelloWorldLayer.h"

// HelloWorldLayer implementation
@implementation HelloWorldLayer

+(CCScene *) scene
{
    CCLOG(@"%@ scene", NSStringFromClass([self class]));
	CCScene *scene = [CCScene node];
	HelloWorldLayer *layer = [HelloWorldLayer node];
	[scene addChild: layer];
	return scene;
}

#define kTagLabelBMFont 1

-(id) init
{
    CCLOG(@"%@ init", NSStringFromClass([self class]));
	if( (self=[super init])) {
        self.isTouchEnabled = YES;
        CGSize winSize = [[CCDirector sharedDirector] winSize];
        CCLabelBMFont *labelBMFont = [CCLabelBMFont labelWithString:@"Hello World" fntFile:@"bitmapFontTest.fnt"];
        labelBMFont.position = ccp(winSize.width/2, winSize.height/2);
        [self addChild:labelBMFont z:0 tag:kTagLabelBMFont];
	}
	return self;
}

- (void)registerWithTouchDispatcher {
    [[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:0 swallowsTouches:YES];
}

- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event {
    return YES;
}

- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event {
//    CCLOG(@"%@ ccTouchEnded", NSStringFromClass([self class]));
    [self explosion:[self getChildByTag:kTagLabelBMFont]];
}

- (void)explosion:(CCNode *)label {
    CGPoint labelPosition = label.position;
//    CCLOG(@"labelPosition = %@", NSStringFromCGPoint(labelPosition));
    for (int i=0; i<[(CCLabelBMFont *)label string].length; i++) {
        CCSprite *sprite = (CCSprite *)[label getChildByTag:i];
        CGPoint point = CGPointZero;
        CGFloat xRand = CCRANDOM_MINUS1_1() > 0 ? - labelPosition.x : 480 - labelPosition.x;
        CGFloat yRand = CCRANDOM_MINUS1_1() > 0 ? - labelPosition.y : 320 - labelPosition.y;
        point = ccp(CCRANDOM_0_1() * xRand, CCRANDOM_0_1() * yRand);
//        CCLOG(@"randPoint = %@", NSStringFromCGPoint(ccp(xRand, yRand)));
        CCLOG(@"point = %@", NSStringFromCGPoint(point));
        id rot = [CCRotateBy actionWithDuration:.5 angle:arc4random() % 360];
        CCMoveTo *moveTo = [CCMoveTo actionWithDuration:.5 position:point];
        id spawn = [CCSpawn actions:rot, moveTo, nil];
        [sprite runAction:spawn];
    }
}

- (void) dealloc
{
    CCLOG(@"%@ dealloc", NSStringFromClass([self class]));
	[super dealloc];
}
@end

b）使用CCAction模拟自由落体  ；碰到边界弹回，散落在地