【麦可网】Cocos2d-X跨平台游戏开发学习笔记---第二十五课：Cocos2D-X物理引擎之Box2D8-10

【麦可网】Cocos2d-X跨平台游戏开发---学习笔记

第二十五课：Cocos2D-X物理引擎之Box2D8-10

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课程目标：

 - 学习Box2D

课程重点：

 - BOX2D概念

 - BOX2D常用操作

 - 使用物理编辑器

考核目标：

 - 能够使用Box2D常用操作

 - 使用物理编辑器完成物理对象编辑

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一、物理编辑器

1.vertexHelper（mac）

2.PhysicsEditor

二、使用PhysicsEditor的实例

HelloPhysicEditor.h-------------------------------------#pragma once#include "cocos2d.h"#include "Box2D/Box2D.h"USING_NS_CC;class HelloPhysicEditor : public cocos2d::CCLayer{private:CCTexture2D* m_pSpriteTexture;b2World* world;public:HelloPhysicEditor();~HelloPhysicEditor();// Here's a difference. Method 'init' in cocos2d-x returns bool, instead of returning 'id' in cocos2d-iphonevirtual bool init();  // there's no 'id' in cpp, so we recommend returning the class instance pointerstatic cocos2d::CCScene* scene();// a selector callbackvoid menuCloseCallback(CCObject* pSender);// implement the "static node()" method manuallyCREATE_FUNC(HelloPhysicEditor);virtual void ccTouchesEnded(CCSet *pTouches, CCEvent *pEvent);void initPhysics();void addNewSpriteAtPosition(CCPoint p);void updata(float dt);};HelloPhysicEditor.cpp-------------------------------------#include "HelloPhysicEditor.h"#include "cocos-ext.h"#include "GB2ShapeCache-x.h"using namespace cocos2d::extension;USING_NS_CC;enum{kTagParentNode = 1,};#define PTM_RATIO 32.0fstring names[] = {"hotdog","drink","icecream","icecream2","icecream3","hamburger","orange"};CCScene* HelloPhysicEditor::scene(){// 'scene' is an autorelease objectCCScene *scene = CCScene::create();// 'layer' is an autorelease objectHelloPhysicEditor *layer = HelloPhysicEditor::create();// add layer as a child to scenescene->addChild(layer);// return the scenereturn scene;}HelloPhysicEditor::HelloPhysicEditor():m_pSpriteTexture(NULL),world(NULL){//加载physicsEditor生成的文件GB2ShapeCache::sharedGB2ShapeCache()->addShapesWithFile("physic_all.plist");}HelloPhysicEditor::~HelloPhysicEditor(){CC_SAFE_DELETE(world);}// on "init" you need to initialize your instancebool HelloPhysicEditor::init(){//////////////////////////////// 1. super init firstif ( !CCLayer::init() ){return false;}setTouchEnabled(true);setAccelerometerEnabled(true);this->initPhysics();CCSpriteBatchNode* blocks = CCSpriteBatchNode::create("blocks.png",100);m_pSpriteTexture = blocks->getTexture();addChild(blocks, 0, kTagParentNode);//scheduleUpdate();this->schedule(schedule_selector(HelloPhysicEditor::updata));return true;}void HelloPhysicEditor::menuCloseCallback(CCObject* pSender){}void HelloPhysicEditor::ccTouchesEnded(CCSet *pTouches, CCEvent *pEvent){CCSetIterator it;CCTouch* touch;for (it=pTouches->begin(); it!=pTouches->end();it++){touch = (CCTouch*)(*it);if (!touch) break;CCPoint location = touch->getLocation();addNewSpriteAtPosition( location );}}void HelloPhysicEditor::initPhysics(){b2Vec2 gravity; gravity.Set(0.0f,-10.0f);world = new b2World(gravity);world->SetAllowSleeping(true);world->SetContinuousPhysics(true);//创建物理空间的范围b2BodyDef groundBodyDef;groundBodyDef.position.Set(0, 0);//创建刚体b2Body* groundBody = world->CreateBody(&groundBodyDef);//创建形状b2EdgeShape groundBox;//创建夹具//将形状绑定到刚体上//buttongroundBox.Set(b2Vec2(0,0), b2Vec2(480/PTM_RATIO, 0));groundBody->CreateFixture(&groundBox, 0);//topgroundBox.Set(b2Vec2(0,320/PTM_RATIO), b2Vec2(480/PTM_RATIO, 320/PTM_RATIO));groundBody->CreateFixture(&groundBox, 0);//leftgroundBox.Set(b2Vec2(0,320/PTM_RATIO), b2Vec2(0, 0));groundBody->CreateFixture(&groundBox, 0);//rightgroundBox.Set(b2Vec2(480/PTM_RATIO,320/PTM_RATIO), b2Vec2(480/PTM_RATIO, 0));groundBody->CreateFixture(&groundBox, 0);}void HelloPhysicEditor::addNewSpriteAtPosition(CCPoint p){string name = names[rand()%7];//定义刚体b2BodyDef bodyDef;bodyDef.type = b2_dynamicBody;bodyDef.position.Set(p.x/PTM_RATIO, p.y/PTM_RATIO);b2Body *body = world->CreateBody(&bodyDef);//定义多边形// b2PolygonShape dynamicBox;// dynamicBox.SetAsBox(.5f, .5f);GB2ShapeCache* sc = GB2ShapeCache::sharedGB2ShapeCache();sc->addFixturesToBody(body, name.c_str());//定义夹具// b2FixtureDef fixtureDef;// fixtureDef.shape = &dynamicBox;//形状// fixtureDef.density = 1.0f;//密度// fixtureDef.friction = 0.3f;//摩擦系数// body->CreateFixture(&fixtureDef);// // CCNode* parent = this->getChildByTag(kTagParentNode);// // int idx = (CCRANDOM_0_1() < 0.5 ? 0 : 1);// int idy = (CCRANDOM_0_1() < 0.5 ? 0 : 1);// if (idx==0 && idy==0)// {// int a =100;// body->SetUserData(&a);// }// CCPhysicsSprite* sprite = CCPhysicsSprite::createWithTexture(m_pSpriteTexture, CCRectMake(32*idx, 32*idy, 32, 32));// parent->addChild(sprite);// sprite->setB2Body(body);// sprite->setPTMRatio(PTM_RATIO);//sprite->setPosition( ccp( p.x, p.y) );//添加上这句在快速创建物理精灵时会出错CCPhysicsSprite* sprite = CCPhysicsSprite::create( (name+".png").c_str());this->addChild(sprite);sprite->setB2Body(body);sprite->setPTMRatio(PTM_RATIO);//sprite->setPosition( ccp(p.x, p.y) );sprite->setAnchorPoint(sc->anchorPointForShape(name.c_str()));}void HelloPhysicEditor::updata(float dt){int velocityIterations = 8;int positionIterations = 1;world->Step(dt, velocityIterations, positionIterations);#if 0//遍历刚体for (b2Body* b=world->GetBodyList(); b; b=b->GetNext()){int* tmp = (int*)b->GetUserData();if (*tmp == 100){//千万不要在这里直接删除b指向的body对象，缓存后在后面删除CCLOG("body is a");}}//遍历碰撞点for ( b2Contact* c=world->GetContactList(); c; c=c->GetNext() ){////千万不要在这里直接删除c指向的碰撞点对象，缓存后在后面删除}#endif}视频中GB2ShapeCache-x.cpp的下载地址：http://download.csdn.net/download/yclmy/8408533

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总结：

物理编辑器真的太方便啦！

 

开心一刻：

蝙蝠深爱麻雀，却被拒绝，

蝙蝠：“为什么，这一切都是为什么？” 

麻雀：“俺妈说了，长得黑也就算了，总爱晚上出去的男人都不是好鸟！”

 

【麦可网】Cocos2d-X跨平台游戏开发---教程下载:http://pan.baidu.com/s/1kTio1Av

【麦可网】Cocos2d-X跨平台游戏开发---笔记系列:http://blog.csdn.net/qiulanzhu