Box2d Bounding Box Without Force

Question

Currently, the Cocos2d-Box2d project is using a b2Vec2 to create a Bounding Box for the edge of the game. Because of this, the bounding Box isn't affecting kinematic bodies, which are bodies that aren't affected by force(meaning that the bodies will usually fly off the screen). I'm trying to see if there's a way to either make the kinematic body connect with the screen. If not, i would appreciate it if someone explain to me how I should make a boundingbox with static bodies around the corner of the screens.

Answer 1

Here is two ways...Try any one

// Method - 1

b2BodyDef groundBodyDef;
groundBodyDef.position.Set(0, 0);  
b2Body              *mGroundBody ;


mGroundBody = self.world->CreateBody(&groundBodyDef);
NSString *strId = @"Ground Body";
mGroundBody->SetUserData(strId);

b2EdgeShape groundBox;      

    //bottom
    groundBox.Set(b2Vec2(0.0f,0.0f), b2Vec2(mS.width/PTM_RATIO,0.0f));
    mGroundBody->CreateFixture(&groundBox,0);

    // top
    groundBox.Set(b2Vec2(0,mS.height/PTM_RATIO), b2Vec2(mS.width/PTM_RATIO, mS.height/PTM_RATIO));
    mGroundBody->CreateFixture(&groundBox,0);


    // left
    groundBox.Set(b2Vec2(0,mS.height/PTM_RATIO), b2Vec2(0,0));
    mGroundBody->CreateFixture(&groundBox,0);

    // right
    groundBox.Set(b2Vec2(mS.width/PTM_RATIO,mS.height/PTM_RATIO), b2Vec2(mS.width/PTM_RATIO,0));
    mGroundBody->CreateFixture(&groundBox,0);

// Method - 2

//create 4 box2d walls...

    float bW = (IS_IPAD) ? (8) : 2 ;
    //top
    {
        b2BodyDef bodyDef;
        bodyDef.type = b2_staticBody;
        bodyDef.position.Set((mS.width*0.5f)/PTM_RATIO, (mS.height)/PTM_RATIO);
        bodyDef.linearDamping  = 0.0f;
        bodyDef.angularDamping = 0.0f;

        bodyDef.userData =  strId ;

        b2PolygonShape box;
        box.SetAsBox( ((mS.width*0.5f)/PTM_RATIO), (bW)/PTM_RATIO);

        b2FixtureDef fixDef;
        fixDef.shape = &box;
        fixDef.density = 1.0f;
        fixDef.friction = 0.1f;
        fixDef.restitution = 1.0f;
        fixDef.isSensor = false;

        b2Body *topBody = self.world->CreateBody(&bodyDef);
        topBody->CreateFixture(&fixDef);

    }

    //bottom
    {
        b2BodyDef bodyDef;
        bodyDef.type = b2_staticBody;
        bodyDef.position.Set((mS.width*0.5f)/PTM_RATIO, 0);
        bodyDef.linearDamping  = 0.0f;
        bodyDef.angularDamping = 0.0f;

        bodyDef.userData =  strId ;

        b2PolygonShape box;
        box.SetAsBox( ((mS.width*0.5f)/PTM_RATIO), (bW)/PTM_RATIO);

        b2FixtureDef fixDef;
        fixDef.shape = &box;
        fixDef.density = 1.0f;
        fixDef.friction = 0.1f;
        fixDef.restitution = 1.0f;
        fixDef.isSensor = false;

        b2Body *topBody = self.world->CreateBody(&bodyDef);
        topBody->CreateFixture(&fixDef);

    }

    //left
    {
        b2BodyDef bodyDef;
        bodyDef.type = b2_staticBody;
        bodyDef.position.Set(0, (mS.height*0.5f)/PTM_RATIO);
        bodyDef.linearDamping  = 0.0f;
        bodyDef.angularDamping = 0.0f;

        bodyDef.userData =  strId ;

        b2PolygonShape box;
        box.SetAsBox( ((bW)/PTM_RATIO), (mS.height*0.5f)/PTM_RATIO);

        b2FixtureDef fixDef;
        fixDef.shape = &box;
        fixDef.density = 1.0f;
        fixDef.friction = 0.1f;
        fixDef.restitution = 1.0f;
        fixDef.isSensor = false;

        b2Body *topBody = self.world->CreateBody(&bodyDef);
        topBody->CreateFixture(&fixDef);

    }

    //right
    {
        b2BodyDef bodyDef;
        bodyDef.type = b2_staticBody;
        bodyDef.position.Set((mS.width)/PTM_RATIO, (mS.height*0.5f)/PTM_RATIO);
        bodyDef.linearDamping  = 0.0f;
        bodyDef.angularDamping = 0.0f;

        bodyDef.userData =  strId ;

        b2PolygonShape box;
        box.SetAsBox( ((bW)/PTM_RATIO), (mS.height*0.5f)/PTM_RATIO);

        b2FixtureDef fixDef;
        fixDef.shape = &box;
        fixDef.density = 1.0f;
        fixDef.friction = 0.1f;
        fixDef.restitution = 1.0f;
        fixDef.isSensor = false;

        b2Body *topBody = self.world->CreateBody(&bodyDef);
        topBody->CreateFixture(&fixDef);
    }