Box2d をやってみる… チュートリアル2 (1)準備

Box2d チュートリアル2個目。

今度こそは１週間以内をノルマでやってみよう…と ^^;

How To Create A Breakout Game with Box2D and Cocos2D 2.X Tutorial

とりあえず、枠とボールを作るところまでを準備 ^^;

//HelloWorld.h
#ifndef __HELLOWORLD_SCENE_H__
#define __HELLOWORLD_SCENE_H__

#include "cocos2d.h"

#include "Box2D.h"
#include "GLES-Render.h"


#define PTM_RATIO   (32.0f)


class HelloWorld : public cocos2d::CCLayer
{
public:
    static cocos2d::CCScene* scene();
    CREATE_FUNC(HelloWorld);

protected:
    virtual bool init();

protected:
    HelloWorld();
    virtual ~HelloWorld();

protected:
    b2World * _world;
    GLESDebugDraw * _debugDraw;

    b2Body * _groundBody;
    b2Fixture * _bottomFixture;
    b2Fixture * _ballFixture;


protected:
    void initPhysics();

protected:
    void update(float delta);
    void draw();
};
#endif

//HelloWorldScene.cpp
#include "HelloWorldScene.h"

USING_NS_CC;

#pragma mark -
CCScene* HelloWorld::scene()
{
    CCScene *scene = CCScene::create();

    HelloWorld *layer = HelloWorld::create();

    scene->addChild(layer);

    return scene;
}

bool HelloWorld::init()
{
    bool result = false;

    do {
        const CCSize visibleSize = CCDirector::sharedDirector()->getVisibleSize();
        const CCPoint origin = CCDirector::sharedDirector()->getVisibleOrigin();
        const CCPoint center = ccpMult(ccpFromSize(visibleSize), 0.5f);

        this->initPhysics();


        //枠
        {
            {
                b2BodyDef bodyDef;
                bodyDef.type = b2_staticBody;
                bodyDef.position.Set(0, 0);

                _groundBody = _world->CreateBody(&bodyDef);
            }

            if (_groundBody)
            {
                b2EdgeShape shape;

                b2FixtureDef fixtureDef;
                fixtureDef.shape = &shape;

                //地面
                shape.Set(b2Vec2(0, 0),
                          b2Vec2(visibleSize.width / PTM_RATIO, 0.0f));
                _bottomFixture = _groundBody->CreateFixture(&fixtureDef);

                shape.Set(b2Vec2(0, 0),
                          b2Vec2(0, visibleSize.height / PTM_RATIO));
                _groundBody->CreateFixture(&fixtureDef);

                shape.Set(b2Vec2(visibleSize.width, visibleSize.height),
                          b2Vec2(0.0f, visibleSize.height));
                _groundBody->CreateFixture(&fixtureDef);

                shape.Set(b2Vec2(visibleSize.width, visibleSize.height),
                          b2Vec2(visibleSize.width, 0.0f));
                _groundBody->CreateFixture(&fixtureDef);
            }
        }

        //ボール
        {
            b2Body * body = NULL;
            {
                CCPoint pos = center;

                CCSprite * sprite = NULL;
                {
                    sprite = CCSprite::create("ball.png");
                    sprite->setPosition(pos);

                    const int tagId = 1;
                    this->addChild(sprite, tagId, tagId);
                }

                {
                    b2BodyDef bodyDef;

                    bodyDef.type = b2_dynamicBody;
                    bodyDef.userData = sprite;
                    bodyDef.position.Set(pos.x / PTM_RATIO, pos.y / PTM_RATIO);

                    body = _world->CreateBody(&bodyDef);
                }

                {
                    b2CircleShape shape;
                    shape.m_radius = (sprite->boundingBox().size.width * 0.5f / PTM_RATIO);

                    b2FixtureDef fixtureDef;
                    fixtureDef.shape = &shape;
                    fixtureDef.density = 1.0f;
                    fixtureDef.friction = 0.0f;
                    fixtureDef.restitution = 1.0f;

                    _ballFixture = body->CreateFixture(&fixtureDef);
                }
            }
        }


        this->scheduleUpdate();

        result = true;
    } while (0);

    return result;
}


#pragma mark -
HelloWorld::HelloWorld()
{
    _world = NULL;
    _debugDraw = NULL;
}


HelloWorld::~HelloWorld()
{
    CC_SAFE_DELETE(_debugDraw);
    _debugDraw = NULL;

    CC_SAFE_DELETE(_world);
    _world = NULL;
}


#pragma mark -
void HelloWorld::initPhysics()
{
    {
        b2Vec2 gravity = b2Vec2(0.0f, -9.8f);
        _world = new b2World(gravity);

        _debugDraw = new GLESDebugDraw(PTM_RATIO);
        {
            uint32 flags = 0;
            {
                flags += b2Draw::e_shapeBit;
            }
            _debugDraw->SetFlags(flags);
        }

        _world->SetDebugDraw(_debugDraw);
    }
}


#pragma mark -
void HelloWorld::update(float delta)
{
    float32 timeStep = (1.0f / 60.0f);
    int32 velocityIterations = 10;
    int32 positionIterations = 10;

    _world->Step(timeStep, velocityIterations, positionIterations);
}


void HelloWorld::draw()
{
    CCLayer::draw();

    //デバッグのための処理...
    {
        ccGLEnableVertexAttribs( kCCVertexAttribFlag_Position );

        kmGLPushMatrix();
        _world->DrawDebugData();
        kmGLPopMatrix();
    }
}

とりあえずこんな感じからスタート ^^;

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