Box2dを動かしてみた (Cocos2d-x v3.2)

Android.mk

LOCAL_PATH := $(call my-dir)

include $(CLEAR_VARS)

$(call import-add-path,$(LOCAL_PATH)/../../cocos2d)
$(call import-add-path,$(LOCAL_PATH)/../../cocos2d/external)
$(call import-add-path,$(LOCAL_PATH)/../../cocos2d/cocos)

LOCAL_MODULE := cocos2dcpp_shared

LOCAL_MODULE_FILENAME := libcocos2dcpp


#--------------------------------------------------------
#コンパイル対象 (Classesフォルダ以下の全てのcppファイルをコンパイル対象)
CPP_FILES := $(shell find $(LOCAL_PATH)/../../Classes -name *.cpp)
 
LOCAL_SRC_FILES := hellocpp/main.cpp 
LOCAL_SRC_FILES += $(CPP_FILES:$(LOCAL_PATH)/%=%)


#--------------------------------------------------------
LOCAL_C_INCLUDES := $(LOCAL_PATH)/../../Classes

#個人的に GLES-Render.cpp/.h を格納してました。
#LOCAL_C_INCLUDES += $(LOCAL_PATH)/../../Classes/Box2d

# LOCAL_C_INCLUDES += $(LOCAL_PATH)/../../cocos2d/external
LOCAL_C_INCLUDES += $(LOCAL_PATH)/../../cocos2d/external/Box2D


#--------------------------------------------------------
LOCAL_WHOLE_STATIC_LIBRARIES := cocos2dx_static
LOCAL_WHOLE_STATIC_LIBRARIES += cocosdenshion_static

LOCAL_WHOLE_STATIC_LIBRARIES += box2d_static
# LOCAL_WHOLE_STATIC_LIBRARIES += cocosbuilder_static
# LOCAL_WHOLE_STATIC_LIBRARIES += spine_static
# LOCAL_WHOLE_STATIC_LIBRARIES += cocostudio_static
# LOCAL_WHOLE_STATIC_LIBRARIES += cocos_network_static
# LOCAL_WHOLE_STATIC_LIBRARIES += cocos_extension_static


#--------------------------------------------------------
include $(BUILD_SHARED_LIBRARY)


#--------------------------------------------------------
$(call import-module,.)
$(call import-module,audio/android)

$(call import-module,Box2D)
# $(call import-module,editor-support/cocosbuilder)
# $(call import-module,editor-support/spine)
# $(call import-module,editor-support/cocostudio)
# $(call import-module,network)
# $(call import-module,extensions)

HelloWorldScene.cpp

#include "HelloWorldScene.h"
//#include "extensions/cocos-ext.h"


USING_NS_CC;
//USING_NS_CC_EXT;


Scene* HelloWorld::createScene()
{
    // 'scene' is an autorelease object
    auto scene = Scene::create();
    
    // 'layer' is an autorelease object
    auto layer = HelloWorld::create();

    // add layer as a child to scene
    scene->addChild(layer);

    // return the scene
    return scene;
}

// on "init" you need to initialize your instance
bool HelloWorld::init()
{
    bool result = false;
    do
    {
        if (!Layer::init())
        {
            break;
        }

        Size visibleSize = Director::sharedDirector()->getVisibleSize();

        this->initPhysics();

        {
            b2Body * body = NULL;
            {
                b2BodyDef bodyDef;
                bodyDef.type = b2_dynamicBody;
                bodyDef.position.Set(visibleSize.width * 0.5f / PTM_RATIO, visibleSize.height / PTM_RATIO);

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

            if (body)
            {
                b2CircleShape circle;
                circle.m_radius = 50.0f / PTM_RATIO;

                b2FixtureDef fixtureDef;
                fixtureDef.shape = &circle;
                fixtureDef.density = 0.4f;
                fixtureDef.friction = 0.5f;
                fixtureDef.restitution = 0.6f;

                body->CreateFixture(&fixtureDef);
            }
        }

        this->scheduleUpdate();

        result = true;
    } while (0);

    return result;
}


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;
//        flags += b2Draw::e_jointBit;
//        flags += b2Draw::e_aabbBit;
//        flags += b2Draw::e_pairBit;
//        flags += b2Draw::e_centerOfMassBit;

        _debugDraw->SetFlags(flags);
    }

    _world->SetDebugDraw(_debugDraw);
}


void HelloWorld::update(float delta)
{
    int velocityIterations = 10;
    int positionIterations = 10;

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

void HelloWorld::draw(Renderer *renderer, const Mat4 &transform, uint32_t flags)
{
    Layer::draw(renderer, transform, flags);

    {
        Director* director = Director::getInstance();

        GL::enableVertexAttribs( cocos2d::GL::VERTEX_ATTRIB_FLAG_POSITION );
        director->pushMatrix(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW);
        _world->DrawDebugData();
        director->popMatrix(MATRIX_STACK_TYPE::MATRIX_STACK_MODELVIEW);
    }
}

HelloWorldScene.h

#ifndef __HELLOWORLD_SCENE_H__
#define __HELLOWORLD_SCENE_H__

#include "cocos2d.h"
#include "Box2D/Box2D.h"
#include "GLES-Render.h"


#define PTM_RATIO   (32.0f)


class HelloWorld : public cocos2d::Layer
{
public:
    static cocos2d::Scene* createScene();

    virtual bool init();

    CREATE_FUNC(HelloWorld);

protected:
    virtual void update(float delta);

    virtual void draw(cocos2d::Renderer *renderer, const cocos2d::Mat4 &transform, uint32_t flags) override;


private:
    b2World * _world;
    GLESDebugDraw * _debugDraw;

    void initPhysics();
};

#endif

解凍したcocos2d-xから以下のファイルをコピーしてプロジェクトに追加する必要があります
/Applications/cocos2d/cocos2d-x-3.2/tests/cpp-tests/Classes/Box2DTestBed/GLES-Render.cpp/.h

プロジェクトの buildSetting の Header Search Path を 以下のように設定
$(SRCROOT)/../cocos2d/external/Box2D

Android.mk ...
① Box2d の includeパスを追加
② #でコメントになっている行を有効化

Cocos2d-x ver.3.6, ver.3.7.1

プロジェクトの PreDefine で CC_ENABLE_BOX2D_INTEGRATION = 1 に設定してもコンパイルが通らない
→ ccConfig.h で以下の記述を追加した...

//MARK: BOX2Dが使いたいときはここで定義し直す(PreDefine ではエラーになる？)
#ifndef CC_ENABLE_BOX2D_INTEGRATION
    #define CC_ENABLE_BOX2D_INTEGRATION 1

    #ifdef CC_ENABLE_CHIPMUNK_INTEGRATION
        #undef CC_ENABLE_CHIPMUNK_INTEGRATION
        #define CC_ENABLE_CHIPMUNK_INTEGRATION 0
    #endif
#endif

Cocos2d-x ver.3.9 ... こちらで新しく試してみました。
https://gist.github.com/takashi1975/d1ea2be790035a7fdbec

↑
CC_ENABLE_BOX2D_INTEGRATION の設定は Application.mk に記述するといいみたい。
http://d.hatena.ne.jp/kimukou_26/20140411/p1