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*Collision Detection Question*: I am dragging some boxes around my screen and I want to create an animation when one box touches another. Is this possible or would I be better off transferring everything to a Canvas? If it is possible, could someone please point me in the right direction. I can deal with the doc; I just don't know where to start to detect collision between boxes in Compose. Thanks!

There is no builtin functionality for this, afaik. You need to do it yourself (for rectangles it’s easy), or use some 2d lubrary for advanced features 

Thanks for the reply. When you say it's easy, could you give me a clue so I can get started. Also, do you have a library to recommend? Or just an example library? Many thanks!

Well, test for rectangle collisions is just comparing for intersection, right? It’s just a couple of comparisons of edges. Draw it on a piece of paper and you’ll figure it out :) I’m on mobile now, so can’t assist you further. As for libs, box2d could work, or may be look for something smaller/easier

Brilliant thanks so much, it'll get me started! :blush:

So the simplest way would be to loop over all the boxes (except the one you're dragging) and check for collision one by one.
For rectangles: <https://stackoverflow.com/questions/31022269/collision-detection-between-two-rectangles-in-java>

Hi yes, I actually have done this before using a canvas. My question was more in relation to the fact that I am using boxes, and that I don't know if it's possible to get the bounds of a box (I mean the Box composable)...

You can get bounds with onGlobalPosition event (don’t remember exact name)

Yeah you can use either `onGlobalPosition` or keep a list of bounds and draw your boxes based on them and update your bounds in your `onDrag` or whatever you have for dragging.
I'm doing something like this:
```val boxes = remember { mutableStateListOf&lt;MyBoxClass&gt;(...) } // Initialize the default bounds here

Box(modifier = Modifier.fillMaxSize()) {
    boxes.forEach { box -&gt;
        Box(modifier = Modifier
                .offset(box.x, box.y)
                .pointerInput(Unit) {
                    // update bounds here
                }
                .size(box.width, box.height))
    }
}```