How to find the center point of Sprite in cocos2dx android using cpp

Question

I am new in cocos2dx android game development, I want to know how can i get the center point of sprite in cocos2dx. I am using the version 3.3.

Let me explain the problem I have one scheduler which call one of my function each 5 seconds. It will change the position of sprint. now over this sprite i want to put another sprite over this sprite exactly center over it. I want to know how to find the center point of running sprint in cocos2dx.

Any help appreciate :)

Thank you

pdeschain · Answer 1 · 2015-05-13T09:34:37.067

0

The following code will center a visual center of sprite on a point.

//your sprite
Sprite * spr = Sprite::create(...);

//a point you want to center the sprite on
Point pointToCenterOn;

//sprite should have 0.5,0.5 pivot in order to have it's center in a specific coordinate
//this code will set sprite's position to the desired point
spr->setPosition(pointToCenterOn);

If you want to do it every frame - use this code in update or schedule a callback to run constantly.

edited May 13 '15 at 09:34

answered May 13 '15 at 08:11

pdeschain

1,411
12
21

Default is 0.5, yes. I meant to suggest changing it in case your pivot is not default :) – pdeschain May 13 '15 at 09:06
Point centerPoint what is this ? – Bhavdip Sagar May 13 '15 at 09:08
I am using cpp in cocos2dx – Bhavdip Sagar May 13 '15 at 09:08
I did not understand the centerPoint – Bhavdip Sagar May 13 '15 at 09:13
Size size = moveSprite->getContentSize(); sprite_tickingBombing->setPosition(Point(size.width * 0.5, size.height * 0.5)); – Bhavdip Sagar May 13 '15 at 09:15
Did not working let me know what is centerPoint( size.width * 0.5f, size.height * 0.5f ); – Bhavdip Sagar May 13 '15 at 09:15
Point centerPoint(...) is equivalent to Point centerPoint = Point(...); - it's just another way of calling a constructor on a variable. centerPoint is an instance of type Point that holds the center value you are trying to calculate. – pdeschain May 13 '15 at 09:18
Then it is not working Actually the getContentSize() of sprite is moving sprite. this sprite dynamically change his position. I want to put the another sprite over on it at run time in center position. – Bhavdip Sagar May 13 '15 at 09:28
getContentSize() does not move the sprite. It seems that you actually don't need to find the center of sprite, you want to center it (verb) on a certain point. I've updated my answer. – pdeschain May 13 '15 at 09:34
I know it does not move the sprite but In my game the sprite is moving dynamically so at run time I want to get the center point of the moving sprite. – Bhavdip Sagar May 13 '15 at 09:44
how to find the center x,y point of the moving sprite in schedule function – Bhavdip Sagar May 13 '15 at 09:46

Lazy Gamer · Answer 2 · 2015-05-13T11:30:08.937

0

if i understand your problem right then you want to place sprite B as a Child of Sprite A. try something like this,

Sprite* parent = Sprite::create("MyTexture.png");
parent->setposition(Vec2(100,100));
this->addChild(parent,2);

Sprite* child = Sprite::create("MyTexture2.png");
child->setposition(Vec2(parent->getBoundingBox().size.width/2,parent->getBoundingBox().size.height/2));
parent->addChild(child,2);

this will place child exactly at the center of parent, Moving parent will result in moving child also,

edited May 13 '15 at 11:30

answered May 13 '15 at 11:24

Lazy Gamer

91
5

Is child must need to add "parent->addChild(child,2);" can i add the Sprite* child as this->addChild(child,2); – Bhavdip Sagar May 13 '15 at 11:49
if u add use this->addChild(child,2); then this child will be added to same layer in which parent is added and you have to move child and parent separately which is a little messy for larger amount of objects, if you want to do it then u can do it like child->setPosition(parent->getPosition)); – Lazy Gamer May 13 '15 at 12:15

score 0 · Answer 3 · answered May 15 '15 at 09:16

void yourLayer::setBg() {
    bg1 = CCSprite::create("menu/menu_bg1.jpg");
    bg1->setAnchorPoint(ccp(0, 0.5));
    bg1->setPosition(ccp(0, visibleSize.height / 2 + origin.y));

    lowerPart1 = CCSprite::create("menu/lower.jpg");

    lowerPart1->setAnchorPoint(ccp(0.5,0.5));
    lowerPart1->setPosition(ccp(bg1->getContentSize().width/2,bg1->getContentSize().height/2));
    bg1->addChild(lowerPart1);
    this->addChild(bg1, 0);
}

void yourLayer::scrollBk() {
    bg1->setPosition(ccp(bg1->getPosition().x - 1, bg1->getPosition().y));


    if (bg1->getPosition().x < -bg1->boundingBox().size.width) {
        bg1->setPosition(
                ccp(0, visibleSize.height / 2 + origin.y));
    }


}

void yourLayer::update(float dt) {

    scrollBk();

}

it should work for you...

How to find the center point of Sprite in cocos2dx android using cpp

3 Answers3