How to create realistic ropes using cocos2d-x and box2d?

cocos2d-x C++
#1

Good day to all!

I have been coding cocos2d-x for some time now and I am starting to integrate box2D
in my game, I am really new in box2D and I have manage to play around with the example with cat and
car for collisions. What I want to achieve now is to have a realistic rope with an object attached
in the end.

I have been trying to port this tutorial ( http://www.cocos2d-iphone.org/archives/1112 ) to android for the whole day and I still
haven’t figure out how to do this. I already have the VRope-x class for Velvet rope
in android https://github.com/teemukorh/VRope-x but it still doesn’t work.

I tried porting the whole tutorial to android and it has no errors when I compiled it but when I try to run it
and press on the play menu to proceed to the game scene it actually stops. No message nor error, it just stops. :frowning:

Can someone please guide me? Any help is greatly appreciated! :slight_smile:

#2

There is the “RopeJoint” test in the Samples/TestCPP project, have you tried that?

#3

This is the port of first part from raywenderlich cut the rope tutorial…
2nd part is not proper but you will get upto rope drawing using verlet rope…

#4

Thanks for your reply, I was able to run the Velvet rope and I am trying to
use CCSprite for the rope and player but I can’t seem to figure out how :; //center body on screen
anchorBody = world>CreateBody(&anchorBodyDef);

CCSpriteBatchNode parent = CCSpriteBatchNode::batchNodeWithFile;
m_pSpriteTexture = parent~~>getTexture;
addChild;
Box2DSprite* sp = addNewSpriteAtPosition);
CCSpriteBatchNode* ropeBatch = CCSpriteBatchNode::batchNodeWithFile;
addChild;
VRope* verlet = createRope;
sp~~>mRope = verlet;
</pre>
and the adddNewSpritePosition function is:
<pre>
Box2DSprite GameScene::addNewSpriteAtPosition(CCPoint p)
{
CCSize size = CCDirector::sharedDirector()>getWinSize;
CCLOG (“Add sprite %0.2f x %02.f”,p.x,p.y);
CCNode* parent = getChildByTag;
//We have a 64x64 sprite sheet with 4 different 32x32 images. The following code is
//just randomly picking one of the images
Box2DSprite **sprite = new Box2DSprite;
sprite>initWithTexture;
sprite~~>setScaleX.width) / 2 ) / 2) / 1.3)) );
sprite~~>setScaleY.height) / 2 ) / 2) / 1.3)) );
sprite~~>autorelease;
parent~~>addChild;
sprite~~>setPosition );
sprite~~>createPhysicsBody;
return sprite;
}
</pre>
and this is the create physicsBody for the sprite:
<pre>
b2BodyDef bodyDef;
bodyDef.type = b2_dynamicBody;
bodyDef.position.Set;
mBody = mWorld~~>CreateBody;
// Define another box shape for our dynamic body.
b2PolygonShape dynamicBox;
dynamicBox.SetAsBox.width** getScaleX) / PTM_RATIO, .height * getScaleY) / PTM_RATIO);//These are mid points for our 1m box
//dynamicBox.SetAsBox;
// Define the dynamic body fixture.
b2FixtureDef fixtureDef;
fixtureDef.shape = &dynamicBox;
fixtureDef.density = 0.5f;
fixtureDef.friction = 0.3f;
mBody~~>CreateFixture(&fixtureDef);

mBody~~>SetUserData;
</pre>
When I tried using CCSprite it doesn’t work,
<pre>
*pSprite = CCSprite::create;
*pSprite~~>setScaleX( ((((( size.width / *pSprite~~>getContentSize.width) / 2 ) / 2) / 1.3)) );
_pSprite~~>setScaleY.height) / 2 ) / 2) / 1.3)) );
*pSprite~~>setPosition );
this~~>addChild(_pSprite, 2);

b2BodyDef bodyDef;
bodyDef.type = b2_dynamicBody;
bodyDef.position.Set(location.x/PTM_RATIO, location.y/PTM_RATIO);

mBody = mWorld~~>CreateBody;
// Define another box shape for our dynamic body.
b2PolygonShape dynamicBox;
dynamicBox.SetAsBox.width * getScaleX) / PTM_RATIO, .height * getScaleY) / PTM_RATIO);//These are mid points for our 1m box
//dynamicBox.SetAsBox;
// Define the dynamic body fixture.
b2FixtureDef fixtureDef;
fixtureDef.shape = &dynamicBox;
fixtureDef.density = 0.5f;
fixtureDef.friction = 0.3f;
mBody~~>CreateFixture(&fixtureDef);

mBody->SetUserData(_pSprite);

Can someone point to me what am I doing wrong? Is there something wrong the way I create fixtures and body?

Thanks!