Utilize simd to synchronize your alignment:

import simd

private struct BoundingBoxParameters {

    let topLeft: float2 = float2(0.0, 0.0)
    let size: float2 = float2(0.0, 0.0)
    let levelOfDetail: Float = 1.0

    init(topLeft: float2,
         size: float2,
         levelOfDetail: Float) {
        self.topLeft = topLeft
        self.size = size 
        self.levelOfDetail = levelOfDetail
}

Utilize simd to synchronize your alignment:

import simd

private struct BoundingBoxParameters {

    let topLeft: float2 = float2(0.0, 0.0)
    let size: float2 = float2(0.0, 0.0)
    let levelOfDetail: Float = 1.0

    init(topLeft: float2,
         size: float2,
         levelOfDetail: Float) {
        self.topLeft = topLeft
        self.size = size 
        self.levelOfDetail = levelOfDetail
    }
}