UnitPoint

public struct UnitPoint : Hashable

A normalized point in an element’s coordinate space.

Use a unit point to represent a location in an element without having to know the element’s rendered size. The point stores a value in each dimension that indicates the fraction of the element’s size in that dimension — measured from the element’s origin — where the point appears. For example, you can create a unit point that represents the center of any element by using the value 0.5 for each dimension:

let unitPoint = UnitPoint(x: 0.5, y: 0.5)

To project the unit point into the rendered element’s coordinate space, multiply each component of the unit point with the corresponding component of the element’s size:

let projectedPoint = CGPoint(
    x: unitPoint.x * size.width,
    y: unitPoint.y * size.height
)

You can perform this calculation yourself if you happen to know an element’s size, but Blueprint typically does this for you to carry out operations that you request, like when you place a subelement in a custom layout.

You can create custom unit points with explicit values, like the example above, or you can use one of the built-in unit points, like zero, center, or topTrailing. The built-in values correspond to the alignment positions of the similarly named, built-in Alignment types.