Cocos2d-x Box2d札记: 愤怒的小鸟demo 弹弓和轨迹实现
Cocos2d-x Box2d笔记: 愤怒的小鸟demo 弹弓和轨迹实现
先上图，源码不多，直接上
#ifndef __HELLOWORLD_SCENE_H__
#define __HELLOWORLD_SCENE_H__
#include "cocos2d.h"
#include "GLES-Render.h"
#include "Box2D/Box2D.h"
using namespace cocos2d;
class HelloWorld : public cocos2d::CCLayer
{
public:
// Here's a difference. Method 'init' in cocos2d-x returns bool, instead of returning 'id' in cocos2d-iphone
virtual bool init();
// there's no 'id' in cpp, so we recommand to return the exactly class pointer
static cocos2d::CCScene* scene();
virtual void draw();
virtual void ccTouchesBegan(CCSet *pTouches, CCEvent *pEvent);
virtual void ccTouchesMoved(CCSet *pTouches, CCEvent *pEvent);
virtual void ccTouchesEnded(CCSet *pTouches, CCEvent *pEvent);
void update(float dt);
public:
b2Body *groundBody;
b2World *world;
CCSpriteBatchNode *batch;
CCSprite *bird;
CCPoint center,currentPoint;
float ratio;
int r,canFly;
LAYER_CREATE_FUNC(HelloWorld);
};
#endif // __HELLOWORLD_SCENE_H__
#include "HelloWorldScene.h"
#define PTM_RATIO 32.0
using namespace cocos2d;
CCScene* HelloWorld::scene()
{
CCScene * scene = NULL;
do
{
// 'scene' is an autorelease object
scene = CCScene::create();
CC_BREAK_IF(! scene);
// 'layer' is an autorelease object
HelloWorld *layer = HelloWorld::create();
CC_BREAK_IF(! layer);
// add layer as a child to scene
scene->addChild(layer);
} while (0);
// return the scene
return scene;
}
// on "init" you need to initialize your instance
bool HelloWorld::init()
{
bool bRet = false;
do
{
//////////////////////////////////////////////////////////////////////////
// super init first
//////////////////////////////////////////////////////////////////////////
CC_BREAK_IF(! CCLayer::init());
CCSize winSize=CCDirector::sharedDirector()->getWinSize();
//create bg
CCSprite *bg=CCSprite::create("bg.png");
ratio=winSize.height/bg->getContentSize().height;
bg->setAnchorPoint(ccp(0,0));
bg->setPosition(ccp(0,0));
bg->setScaleY(ratio);
this->addChild(bg,-2);
//load source
batch=CCSpriteBatchNode::create("bird2.png");
this->addChild(batch);
CCTexture2D *batchTexture=batch->getTexture();
//init slingshot
CCSprite*slingshot1=CCSprite::create(batchTexture,CCRectMake(1,1,38,199));
slingshot1->setScale(ratio*0.7);
slingshot1->setPosition(ccp(90,ratio*130));
batch->addChild(slingshot1);
CCSprite*slingshot2=CCSprite::create(batchTexture,CCRectMake(833,1,43,124));
slingshot2->setScale(ratio*0.7);
slingshot2->setPosition(ccp(78,ratio*155));
batch->addChild(slingshot2);
//init bird
bird=CCSprite::create(batchTexture,CCRectMake(1,379,31,30));
bird->setScale(ratio);
bird->setPosition(ccp((slingshot1->getPositionX()+slingshot2->getPositionX())/2,slingshot1->getPositionY()*1.4));
center=bird->getPosition();
this->addChild(bird);
//define the world
b2Vec2 gravity;
gravity.Set(0.0f, -10.0f);
world = new b2World(gravity);
// Do we want to let bodies sleep?
world->SetAllowSleeping(true);
world->SetContinuousPhysics(true);
// Define the ground body.
b2BodyDef groundBodyDef;
groundBodyDef.position.Set(0, 0); // bottom-left corner
// Call the body factory which allocates memory for the ground body
// from a pool and creates the ground box shape (also from a pool).
// The body is also added to the world.
b2Body* groundBody = world->CreateBody(&groundBodyDef);
// Define the ground box shape.
b2EdgeShape groundBox;
CCSize s=CCSize(bg->getContentSize().width,bg->getContentSize().height*ratio);
// bottom
groundBox.Set(b2Vec2(0,slingshot2->getPositionY()/PTM_RATIO/2.1), b2Vec2(s.width/PTM_RATIO,slingshot2->getPositionY()/PTM_RATIO/2.1));
groundBody->CreateFixture(&groundBox,0);
// top
groundBox.Set(b2Vec2(0,s.height/PTM_RATIO), b2Vec2(s.width/PTM_RATIO,s.height/PTM_RATIO));
groundBody->CreateFixture(&groundBox,0);
// left
groundBox.Set(b2Vec2(0,s.height/PTM_RATIO), b2Vec2(0,0));
groundBody->CreateFixture(&groundBox,0);
// right
groundBox.Set(b2Vec2(s.width/PTM_RATIO,s.height/PTM_RATIO), b2Vec2(s.width/PTM_RATIO,0));
groundBody->CreateFixture(&groundBox,0);
GLESDebugDraw*m_debugDraw = new GLESDebugDraw( PTM_RATIO );
world->SetDebugDraw(m_debugDraw);
uint32 flags = 0;
//flags += b2Draw::e_shapeBit;
//flags += b2Draw::e_jointBit;
//flags += b2Draw::e_aabbBit;
// flags += b2Draw::e_pairBit;
// flags += b2Draw::e_centerOfMassBit;
m_debugDraw->SetFlags(flags);
//init
r=60;//活动范围
canFly=0;
setTouchEnabled(true);
scheduleUpdate();
this->runAction(CCFollow::create(bird,CCRectMake(0,0,bg->getContentSize().width,bg->getContentSize().height*ratio)));
bRet = true;
} while (0);
return bRet;
}
void HelloWorld::ccTouchesBegan(CCSet *touches, CCEvent *pEvent)
{
}
void HelloWorld::ccTouchesMoved(CCSet *touches, CCEvent *pEvent)
{
CCTouch *touch=(CCTouch*)touches->anyObject();
CCPoint pt1=touch->locationInView();
pt1=CCDirector::sharedDirector()->convertToGL(pt1);
CCSize s=CCDirector::sharedDirector()->getWinSize();
if(CCRect::CCRectContainsPoint(bird->boundingBox(),pt1)==false)
return;
canFly=1;
float distance=ccpDistance(pt1,center);
if(distance>r)
{
CCPoint pos;
float cos=(pt1.x-center.x)/distance,sin=(pt1.y-center.y)/distance;
pos.x=center.x+r*cos;
pos.y=center.y+r*sin;
bird->setPosition(pos);
}else
{
bird->setPosition(pt1);
}
}
void HelloWorld::ccTouchesEnded(CCSet *touches, CCEvent *pEvent)
{
CCTouch *touch=(CCTouch*)touches->anyObject();
CCPoint pt1=touch->locationInView();
pt1=CCDirector::sharedDirector()->convertToGL(pt1);
if(canFly==0)
{
return;
}else
{
canFly=0;
}
float distance=ccpDistance(pt1,center);
float cos=(pt1.x-center.x)/distance,sin=(pt1.y-center.y)/distance;
//add box2d body
b2CircleShape birdShape;
birdShape.m_radius=ratio*bird->getContentSize().width/PTM_RATIO/2;
//CCLOG("%f",birdShape.m_radius);
b2FixtureDef birdFixtureDef;
birdFixtureDef.shape=&birdShape;
birdFixtureDef.density=1;
birdFixtureDef.friction=0.3;
birdFixtureDef.restitution=0.1;
b2BodyDef birdBodyDef;
birdBodyDef.type=b2_dynamicBody;
birdBodyDef.position.Set(bird->getPositionX()/PTM_RATIO,bird->getPositionY()/PTM_RATIO);
b2Body *birdBody=world->CreateBody(&birdBodyDef);
birdBody->SetUserData(bird);
birdBody->CreateFixture(&birdFixtureDef);
birdBody->ApplyForce(b2Vec2(-5.5f*distance*cos,-5.5f*distance*sin),birdBody->GetWorldCenter());
birdBody->SetLinearDamping(0.2f);
}
void HelloWorld::update(float dt)
{
int32 velocityIterations = 8;
int32 positionIterations = 8;
// Instruct the world to perform a single step of simulation.
world->Step(dt, velocityIterations, positionIterations);
for (b2Body* b = world->GetBodyList(); b; b = b->GetNext())
{
CCSprite *myActor = (CCSprite*)b->GetUserData();
if (myActor)
{
//Synchronize the AtlasSprites position and rotation with the corresponding body
myActor->setPosition(CCPointMake( b->GetPosition().x * PTM_RATIO, b->GetPosition().y * PTM_RATIO));
myActor->setRotation(-1 * CC_RADIANS_TO_DEGREES(b->GetAngle()));
}
}
//CCLOG("%f",dt);
static float countTime=0.0f;
countTime+=dt;
if((countTime>0.08f)&&(bird->getPositionX()>center.x+r)&&(bird->getPositionY()>center.y))
{
countTime=0;
//show the route
CCSprite *route=CCSprite::create(batch->getTexture(),CCRectMake(0,345,35,33));
route->setScale(0.4*ratio);
batch->addChild(route);
route->setPosition(bird->getPosition());
}
}
void HelloWorld::draw()
{
//
// IMPORTANT:
// This is only for debug purposes
// It is recommend to disable it
//
CCLayer::draw();
ccGLEnableVertexAttribs( kCCVertexAttribFlag_Position );
kmGLPushMatrix();
glLineWidth(3.0f);
world->DrawDebugData();
kmGLPopMatrix();
//draw line
if(canFly==1)
{
CHECK_GL_ERROR_DEBUG();
// line: color, width, aliased
// glLineWidth > 1 and GL_LINE_SMOOTH are not compatible
// GL_SMOOTH_LINE_WIDTH_RANGE = (1,1) on iPhone
// glDisable(GL_LINE_SMOOTH);
glLineWidth( 4.0f );
ccDrawColor4B(0,0,0,255);
ccDrawLine( ccpAdd(center,ccp(bird->getContentSize().width/3,0)), bird->getPosition() );
ccDrawLine( ccpAdd(center,ccp(-bird->getContentSize().width/3,0)), bird->getPosition() );
}
}
资源图在这：