Cocos2d-x's box2d Preliminary examination

Physical Engine: The physical code used to simulate a set of physical events.

#ifndef __helloworld_scene_h__

#define __helloworld_scene_h__

#include "Cocos2d.h"

#include <Box2D/Box2D.h>

#define RATIO 80.0f

Class Helloworld:public Cocos2d::layer,public B2contactlistener

{

Private

B2world *world;

B2body *groundbody;

Public

Static cocos2d::scene* Createscene ();

virtual BOOL init ();

void Menuclosecallback (cocos2d::ref* psender);

virtual void update (float DT);

virtual void Begincontact (b2contact* contact);

void Addrect (float x,float y,b2bodytype type);

void Addground ();

Create_func (HelloWorld);

};

#endif//__helloworld_scene_h__

#include "HelloWorldScene.h"

USING_NS_CC;

scene* Helloworld::createscene ()

{

Auto scene = Scene::create ();

Auto layer = Helloworld::create ();

Scene->addchild (layer);

return scene;

}

BOOL Helloworld::init ()

{

if (! Layer::init ())

{

return false;

}

Size visiblesize = director::getinstance ()->getvisiblesize ();

VEC2 origin = Director::getinstance ()->getvisibleorigin ();

Create a world

World=new B2world (B2VEC2 (0,-10));

World->setcontactlistener (this);

Addground ();

Addrect (5,5,b2_dynamicbody);

Addrect (1,5,b2_kinematicbody);//floating objects, not affected by gravity

Scheduleupdate ();

return true;

}

void Helloworld::update (float dt) {

World->step (dt,8,3);

Sprite *s;

For (B2body *b=world->getbodylist (); B;b=b->getnext ()) {

if (B->gettype () ==b2_dynamicbody) {

Log ("%f", B->getposition (). y);

if (B->getuserdata ()) {

S= (sprite*) b->getuserdata ();

S->setposition (B->getposition (). X*ratio,b->getposition (). Y*ratio);

}

//}

}

}

void Helloworld::begincontact (B2contact *contact) {

if (Contact->getfixturea ()->getbody () ==groundbody| | Contact->getfixtureb ()->getbody () ==groundbody) {

Log ("An object landed on the floor");

}

}

void Helloworld::addrect (float positionx,float positiony,b2bodytype type) {

Config box2d

B2bodydef def;

DEF.POSITION=B2VEC2 (Positionx,positiony);

DEF.LINEARVELOCITY=B2VEC2 (1,0);

DEF.LINEARVELOCITY=B2VEC2 (0,10);

Def.type=type;

Groundbody=world->createbody (&DEF);

B2polygonshape shape;

Shape. Setasbox (0.5,0.5);

B2fixturedef Fixturedef;

Fixturedef.density=1;

fixturedef.friction=0.3;

fixturedef.shape=&shape;

Groundbody->createfixture (&FIXTUREDEF);

Config Cocos shape

Auto S=sprite::create ();

S->settexturerect (Rect (0,0,0.5*2*ratio,0.5*2*ratio));

AddChild (s);

S->setposition (Point (Def.position.x*ratio,def.position.y*ratio));

Groundbody->setuserdata (s);

}

void Helloworld::addground () {

B2bodydef def;

DEF.POSITION=B2VEC2 (400/ratio,0);

Def.type=b2_staticbody;

B2body *body=world->createbody (&DEF);

B2polygonshape Groundshape;

Groundshape.setasbox (400/ratio,0.5);

B2fixturedef Fixuredef;

Fixuredef.density=1;

fixuredef.friction=0.3;

fixuredef.shape=&groundshape;

Body->createfixture (&FIXUREDEF);

}

void Helloworld::menuclosecallback (ref* psender)

{

Director::getinstance ()->end ();

#if (Cc_target_platform = = Cc_platform_ios)

Exit (0);

#endif

}

Cocos2d-x's box2d Preliminary examination