cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   brett
   Member

   I have a layer which is my background... I use a ScaleTo action on it to scale it by 0.5. The problem is when I change a position of an atlas sprite (child of background layer), it doesn't make sense to me why its putting it in that position. For example, if you take a look at the image below, the yellow box's x value is 0, and the blue box is 240. (The background layer's contentSize is 480x320). I just can't understand why 0 would be there and 240 would be where it is. Could some one please explain.

   

   Posted 2 years ago #
2. 

   brett
   Member

   (sorry forget to say I'm talking about the x axis for 0 and 240)

   Posted 2 years ago #
3. 

   mhussa
   Member

   Your scaling your background by half so the box is in the right(scaled) place. Imagine you can see your background from directly above and you've just zoomed out (by scaling), 0,0 would move in towards the centre.

   Posted 2 years ago #
4. 

   brett
   Member

   Thanks Mhussa, that makes sense, but could you tell me how I'd get the new top left & bottom right pixel x/y coordinates for the image once its scaled by 0.5.

   Posted 2 years ago #
5. 

   mhussa
   Member

   If you mean screen co-ordinates then you can try:

   - (CGPoint)convertToWindowSpace:(CGPoint)nodePoint

   screenPos = [layer convertToWindowSpace:sprite.position];

   The CCNode object has lots of other point transform methods, and I don't understand all of them. A good habit to get into is to look into the cocos2d source code, you can either find an answer to your problem or learn something new. A very important aspect of open source is this kind of access.

   I'm guessing you're new to this, since I am/was as well I'll tell you the steps I use to find answers.

   1) search forum - The same path has been trodden by lots of people before me, most of my questions are answered this way.
   2) search wiki - useful nuggets/overview stuff.
   3) search cocos2d source code - the main reference.
   4) ask question on forum - online support.

   I've not needed 4) yet.

   good luck.

   Posted 2 years ago #
6. 

   brett
   Member

   Thanks again Mhussa, yes, I've just started working with coco os 2d last week. It's really amazing how easy it makes things.

   Posted 2 years ago #

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