Convert grid positions to absolute positions - json

Question

I have a big issue, but I don't know how to solve it.
I have a json file, which contains elements and their positions in a grid.
All elements possible have childrens, and the childrens are re-indexed from zero (0,0).
I need to convert relative positions to 'absolute' position.
An example json file:
{
label: 'item 1',
position: {x: 0, y: 0},
childrens: [
{
label: 'item 1 children 1'
position: {x: 1, y: 0}
},
{
label: 'item 1 children 2',
position: {x: 2, y: 0}
}
]
},
{
label: 'item 2',
position: {x: 1, y: 0},
childrens: [
{
label: 'item 2 children 1',
position : {x: 0, y: 2}
}
]
}

Answer 1

Keep an absolute offset.
Start with offset (0,0) for the root node. Then when you reach a child compute the absolute coordinates for the top-left corner and call the recursive function with the computed coordinates as the new absolute offset.
For regular items add the absolute offset to the item coordinates to get the absolute coordinates.
In your example, you start with offset (0,0). Then you reach the child rectangle. You compute that the top-left corner should be at position (2,0) and send that as the offset into the recursive call. When you reach the first block inside the child you compute the absolute coordinates as child relative coordinates: (0,0) + absolute coordinate: (2,0) to get (2,0).