AVMetaDataObject.bounds to SwiftUI position? - swift

Question

I have two views. The parent view holds a CameraFeed UIViewControllerRepresentable which passes back the bounds of a AVMetadataFaceObject. I'm trying to draw overlays where that bounds should be. I'm getting kind of close, but my mappings aren't quite right. The CameraFeed passes back a scalar-style set of bounds and I'm multiplying my geometry reader by it.
The X and the Y seem to be swapped? (orange square works wrong and blue square works better)
The location doesn't QUITE line up perfectly.
Acknowledgements: Thanks to the HackingWithSwift InstaFilter and Hot Prospects examples, btw. They were very helpful to getting this far.
I do understand that there is a CALayer that I could draw on in the AV object, and if I went that way I could use the more powerful Vision framework but I was seeing if I could try this approach first. I also am aware that there is a CIFaceFeature I could be using too. Also, I don't have a TrueDepth front-facing camera to work with. I just wanted to see if I could hijack this seemingly simplest of solutions to make it work.
What am I missing about the how how the bounds of AVMetaDataObject work and approaches to doing the frame of reference transformation? Thanks in advance. Full Code on GitHub
struct CameraFeedView: View {
#State var foundFace:CGRect?
#State var geometryRect:CGRect = CGRect(x: 0, y: 0, width: 0, height: 0)
//#State var foundFaceAdjusted:CGRect?
//var testRect:CGRect = CGRect(
// x: 0.44112000039964916,
// y: 0.1979580322805941,
// width: 0.3337599992007017,
// height: 0.5941303606941507)
var body: some View {
GeometryReader(content: { geometry in
ZStack {
CameraFeed(codeTypes: [.face], completion: handleCameraReturn)
if (foundFace != nil) {
Rectangle()
.stroke()
.foregroundColor(.orange)
.frame(width: 100, height: 100, alignment: .topLeading)
.position(
x: geometry.size.width * foundFace!.origin.x,
y: geometry.size.height * foundFace!.origin.y)
FoundObject(frameRect: geometryRect, boundsRect: foundFace!)
.stroke()
.foregroundColor(.blue)
}
}
.onAppear(perform: {
let frame = geometry.frame(in: .global)
geometryRect = CGRect(
origin: CGPoint(x: frame.minX, y: frame.minY),
size: geometry.size
)
})
})
}
func handleCameraReturn(result: Result<CGRect, CameraFeed.CameraError>) {
switch result {
case .success(let bounds):
print(bounds)
foundFace = bounds
//TODO: Add a timer
case .failure(let error):
print("Scanning failed: \(error)")
foundFace = nil
}
}
}
struct FoundObject: Shape {
func reMapBoundries(frameRect:CGRect, boundsRect:CGRect) -> CGRect {
//Y bounded to width? Really?
let newY = (frameRect.width * boundsRect.origin.x) + (1.0-frameRect.origin.x)
//X bounded to height? Really?
let newX = (frameRect.height * boundsRect.origin.y) + (1.0-frameRect.origin.y)
let newWidth = 100//(frameRect.width * boundsRect.width)
let newHeight = 100//(frameRect.height * boundsRect.height)
let newRect = CGRect(
origin: CGPoint(x: newX, y: newY),
size: CGSize(width: newWidth, height: newHeight))
return newRect
}
let frameRect:CGRect
let boundsRect:CGRect
func path(in rect: CGRect) -> Path {
var path = Path()
path.addRect(reMapBoundries(frameRect: frameRect, boundsRect: boundsRect))
return path
}
}