p图demo小应用。想怎么p就怎么p

本文參考于http://blog.csdn.net/xiaominghimi/article/details/6776096和http://www.cnblogs.com/liufan9/archive/2013/04/11/3012275.html。

于上面基于cocos2d-x 2.0不一样的地方，本本是基于cocos2d-x 3.0。

首先。当然是下载和安装cocos2d-x 3.0了，网址：http://www.cocos2d-iphone.org/download。

其次，下载Box2d，网址：https://github.com/vegerjiang/Box2d。

创建一个cocos2d的项目（怎么创建这里不重述了），添加Box2d库（直接拖到Libraries文件夹），在Build Settings->Search Paths->Head Search Paths中添加一项"$(SRCROOT)/$(PROJECT_NAME)/Libraries"。

假设能编译执行成功，说明你已经建好了一个空的基于cocos2d-x 3.0和Box2d的ios项目了。

新建一个ooc类HelloLay，这里须要注意亮点：

1.HelloLay必须继承于CCLayout。

2.HelloLay.m改名为HelloLay.mm。

具体代码请从https://github.com/vegerjiang/testBox2d下载，具体的解释请參照http://www.cnblogs.com/liufan9/archive/2013/04/11/3012275.html。

为了方面某些懒童鞋。以下把类HelloLay的.h文件和.mm文件贴出来。

p图demo小应用，想怎么p就怎么p

HelloLay.h文件

//
//  HelloLayer.h
//  testBox2d
//
//  Created by JiangHuifu on 14-5-28.
//  Copyright (c) 2014年 veger. All rights reserved.
//
#import "cocos2d.h"
#import "cocos2d-ui.h"#import "CCLayout.h"#define PTM_RATIO 32.0
@interface HelloLayer : CCLayout
+(id)scene;
@end

HelloLay.mm文件

p图demo小应用，想怎么p就怎么p

//
//  HelloLayer.m
//  testBox2d
//
//  Created by JiangHuifu on 14-5-28.
//  Copyright (c) 2014年 veger. All rights reserved.
//#import "HelloLayer.h"
#import "Box2D.h"
@interface HelloLayer(){b2World* _world;b2Body* _body;CCSprite* _ball;
}
@property(nonatomic,strong) CCSprite* ball;
@end
@implementation HelloLayer
@synthesize ball = _ball;
+(id)scene{CCScene* scene = [CCScene node];HelloLayer* layer = [HelloLayer node];[scene addChild:layer];return scene;
}
-(id)init{if (self = [super init]) {CGSize winSize = [[CCDirector sharedDirector] viewSize];//Create sprite and add it to the layout_ball = [CCSprite spriteWithImageNamed:@"ball.png"];_ball.scaleX = 52 / _ball.contentSize.width;_ball.scaleY = 52 / _ball.contentSize.height;_ball.position = ccp(100, 300);[self addChild:_ball];//Create a worldb2Vec2 gravity = b2Vec2(0.0f,-8.0f);_world = new b2World(gravity);//Create edges around the entire screenb2BodyDef groundBodyDef;groundBodyDef.position.Set(0, 0);b2Body* groundBody = _world->CreateBody(&groundBodyDef);b2EdgeShape groundEdge;b2FixtureDef boxShapeDef;boxShapeDef.shape = &groundEdge;//wall definitionsgroundEdge.Set(b2Vec2(0, 0), b2Vec2(winSize.width/PTM_RATIO, 0));groundBody->CreateFixture(&boxShapeDef);groundEdge.Set(b2Vec2(0,0), b2Vec2(0, winSize.height/PTM_RATIO));groundBody->CreateFixture(&boxShapeDef);groundEdge.Set(b2Vec2(0,winSize.height/PTM_RATIO), b2Vec2(winSize.width/PTM_RATIO,winSize.height/PTM_RATIO));groundBody->CreateFixture(&boxShapeDef);groundEdge.Set(b2Vec2(winSize.width/PTM_RATIO,winSize.height/PTM_RATIO), b2Vec2(winSize.width/PTM_RATIO, 0));groundBody->CreateFixture(&boxShapeDef);//Create ball body and shapeb2BodyDef ballBodyDef;ballBodyDef.type = b2_dynamicBody;ballBodyDef.position.Set(100/PTM_RATIO, 100/PTM_RATIO);ballBodyDef.userData = (__bridge void*)_ball;_body = _world->CreateBody(&ballBodyDef);b2CircleShape circle;circle.m_radius = 26.0/PTM_RATIO;b2FixtureDef ballShapeDef;ballShapeDef.shape = &circle;ballShapeDef.density = 1.0f;ballShapeDef.friction = 0.2f;ballShapeDef.restitution = 0.8f;_body->CreateFixture(&ballShapeDef);[self schedule:@selector(tick:) interval:0.017];[self schedule:@selector(kick) interval:5.0];self.userInteractionEnabled = YES;}return self;
}
-(void)tick:(CCTime) dt{_world->Step(dt, 10, 10);for (b2Body* b = _world->GetBodyList(); b; b=b->GetNext()) {CCSprite* ballData = (__bridge CCSprite*)b->GetUserData();ballData.position = ccp(b->GetPosition().x*PTM_RATIO,b->GetPosition().y*PTM_RATIO);ballData.rotation = -1 * CC_RADIANS_TO_DEGREES(b->GetAngle());}
}
-(void)kick{b2Vec2 force = b2Vec2(30, 30);_body->ApplyLinearImpulse(force, _body->GetPosition());
}
-(void)touchBegan:(UITouch *)touch withEvent:(UIEvent *)event{b2Vec2 force = b2Vec2(-30,30);_body->ApplyLinearImpulse(force, _body->GetPosition());
}-(void)touchEnded:(UITouch *)touch withEvent:(UIEvent *)event{NSLog(@"touchEnded");
}-(void)dealloc{delete _world;_body = NULL;_world = NULL;
}
@end