Problem with Physics and Last version

cocos2d-x C++
#1

Hi,

Im making a new game with latest version and i have some problems with physics.

I make a boundary and a floor physics objects to prevent player go out of screen, but it is going down every time, like ignoring all physics things.

Here is a video:

Here is the player with “setDynamic(false)”:

My scene code:

Scene* GameScene::createScene()
{
    auto scene = Scene::createWithPhysics();
    scene->getPhysicsWorld()->setGravity(Vec2(0.0f, -1.0f));
    
    auto gameLayer = GameScene::create();
    scene->addChild(gameLayer);
    gameLayer->toggleDebug();
    
    return scene;
}

My player creation code:

auto playerPhysicsBody = PhysicsBody::createBox(Size(100.0f, 100.0f), PhysicsMaterial(10, 1.0f, 0.5f), Vec2(0.0f, 0.0f));
playerPhysicsBody->setRotationEnable(false);
playerPhysicsBody->setContactTestBitmask(0xFFFFFFFF);
character->setPhysicsBody(playerPhysicsBody);
character->getSprite()->addComponent(character->getPhysicsBody());

My init code:

bool GameScene::init()
{
    if (!Layer::init())
    {
        return false;
    }
    
    auto visibleSize = Director::getInstance()->getVisibleSize();
    Vec2 origin = Director::getInstance()->getVisibleOrigin();
    
    createBackgroundWithAnimation();
    createPlayer();
    
    auto label = Label::createWithTTF("Points", "fonts/Marker Felt.ttf", 20);
    label->setPosition(Vec2(visibleSize.width - label->getContentSize().width - 10, origin.y + visibleSize.height - label->getContentSize().height));
    label->setAlignment(TextHAlignment::RIGHT);
    label->setAnchorPoint(Vec2(0.0f, 1.0f));
    this->addChild(label);
    
    auto edgeBody = PhysicsBody::createEdgeBox(visibleSize, PHYSICSBODY_MATERIAL_DEFAULT, 3);
    edgeBody->setContactTestBitmask(0xFFFFFFFF);
    auto edgeNode = Node::create();
    edgeNode->setPosition(Point(visibleSize.width / 2 + origin.x, visibleSize.height / 2 + origin.y));
    edgeNode->setPhysicsBody(edgeBody);
    this->addChild(edgeNode);
    
    auto bottomBody = PhysicsBody::createBox(Size(visibleSize.width, 20));
    bottomBody->setDynamic(false);
    bottomBody->setContactTestBitmask(0xFFFFFFFF);
    auto bottomNode = Node::create();
    bottomNode->setPosition(Point(visibleSize.width/2, 50));
    bottomNode->setPhysicsBody(bottomBody);
    this->addChild(bottomNode);
    
    this->scheduleUpdate();
    
    return true;
}

And my update code:

void GameScene::update(float delta)
{
    Layer::update(delta);
    
    parallaxNode->setPosition(parallaxNode->getPosition() + Vec2(-2.0f, 0.0f));
    parallaxNode->updatePosition(Vec2(-2.0f, 0.0f));
}

Can anyone help me?

#2

Please…any help?

#3

I don’t use the inbuilt physics, - but it looked like it was moving very fast from the video - so it could be just travelling too fast through the floor.

#4

Yes. This is the problem. Im setting the gravity to 0.1 to check, but with any value the problem happen.

I dont know what to do. I already debug the library code and appear be fine.

Is another thing that i cant see.

Can anyone help me?

#5

Things I would try:
set the gravity to zero - if it still moves as fast then it must be being given some initial velocity -
set the mass to zero - same reason.
set gravity to (1,0) - does it move to the right ? If not, then again it points to something giving it an initial velocity.

Sorry can’t be more help

#6

Hi,

Thanks, but the screenshot is exactly it, the gravity = Zero. Without gravity the player is stopped, like on screenshot. But any physics is making it be crazy.

Thanks.

#7

are you running any MoveTo or MoveBy action on your player sprite? If yes then disable it,

#8

My latest project work with physic and have same error like you. But i solved it like this =

void FlappyBirdCloneGameView::createPlayer() {
    
    CCLOG("Player Created");
    
    bird = Sprite::create("bird/Bird1.png");
    
    bird->setPosition(Vec2(VW * 0.4 + (50*contentScaleX), VH * 0.4 + (50*contentScaleY)));
    
    bird->setScale(contentScaleX + FIX_VALUE_SCALE, contentScaleY + FIX_VALUE_SCALE);
    
    auto birdBody = PhysicsBody::createCircle(bird->getContentSize().width/2, PhysicsMaterial(DENSITY,1,0));
    
    animateBird();
    
    birdBody->setPositionOffset(Vec2(0, 55));
    
    bird->setPhysicsBody(birdBody);
    
    this->addChild(bird, 300);
    
    bird->getPhysicsBody()->setDynamic(false);
    
}

void FlappyBirdCloneGameView::animateBird() {
    Vector<SpriteFrame*> animFrames(4);
    char str[100] = {0};
    for(int i = 1; i < 4; i++)
    {
        sprintf(str, "bird/Bird%d.png",i);
        auto frame = SpriteFrame::create(str,Rect(0, 0, 48, 48)); //we assume that the sprites' dimentions are 40*40 rectangles.
        frame->setAnchorPoint(Vec2(0, 0));
        animFrames.pushBack(frame);
    }
    
    auto animation = Animation::createWithSpriteFrames(animFrames, 0.1f);
    animation->setLoops(-1);
    auto animate = Animate::create(animation);
    bird->runAction(animate);

}


Scene* FlappyBirdCloneGameView::createScene()
{
    
    auto scene = Scene::createWithPhysics();
    scene->getPhysicsWorld()->setGravity(Vec2(0, GRAVITY));
    scene->getPhysicsWorld()->setDebugDrawMask(PhysicsWorld::DEBUGDRAW_ALL);
    
    auto layer = FlappyBirdCloneGameView::create();
    layer->setPhysicWorld(scene->getPhysicsWorld());
    
    scene->addChild(layer);
    
    return scene;
}
#9

Hi @Lazy_Gamer,

Im not moving the player, i dont reach this part of game, im only creating it and putting on screen, nothing more.

@adesuluh,

I already try it:
gameLayer->setPhysicWorld(scene->getPhysicsWorld());

But i dont know why, the method “setPhysicWorld” not exist or was removed from cocos2d-x.

Screenshot 2017-05-04 15.34.34.png2048×520 82.8 KB

:frowning:

#10

I put the game source code on my github:

It is easy now to detect the problem.

This will be a sample game to be used as a reference for other games and after finish my goals with it, i will put a free version on appstore and playstore, and can be a use case open source.

Can anyone help me?

#11

Hi,

With my sample project can anyone help understand what is wrong?

Thanks.

#12

Hi,

I solve the problem with strange behavior of player sprite. I cant create sprite without image. I change the project on github with the correct code and it is working, but i get other problem. Player is moving automatic o.o

Can anyone help me?

#13

Hi,

I solved the problem. I solved adjusting the pivot on TexturePacker. But im stop on another problem. When i click on joystick button, i get crash, i think because a problem with retain, i dont know. Can anyone help me?

Thanks.

#14

Hi,

The project:

And the video:

Thanks for any help.

#15

What is the problem you have now?

Edit: I see. Can I clone the repo?

#16

Hi,

My problem is what showd on video. After click on button A, the app crash when the animation will be changed.

Thanks.

#17

And you can clone the repo, yes.

#18

Can you help me? I dont know if i need put retain/release or something like this.

:frowning:

#19

Ok. Thanks. I’ll remind myself tomorrow. Or email me to remind me. Slackmoehrle@cocos2d-x.org

#20

Can anyone help me please?