Circle stuck at top left hand corner of screen swiftUI - swift

Question

I'm trying to draw a circle in SwiftUI at a constantly changing variable poseEstimator.bodyparts[.leftshoulder]!.location of type CGPoint on my View, and the end goal is that when the variable changes, I want the circle on the screen to move to the new coordinates stored in the variable.
I read up online on how to draw a circle in swiftUI and found out that you need to use the Circle() class to draw a circle, so that's what I did, but for some reason, my circle is always stuck at top left hand corner of the screen(0.0, 0.0), and even when I change the .position property of the circle to CGPoint(0.5,0.5), the circle is still stuck at the exact same location as before.
This is my swiftUI view struct:
import SwiftUI
struct StickFigureView: View { //declare the stickfigure for pose esimation as a swift view
#ObservedObject var poseEstimator: PoseEstimator
var size: CGSize
var body: some View {
if poseEstimator.bodyParts.isEmpty == false { //add in the sticks only if there are VNPoints stored in "bodyparts"
ZStack {
// Right leg
if poseEstimator.bodyParts[.rightAnkle]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.rightKnee]!.location != CGPoint(x: 0.0, y: 1.0){
Stick(points: [poseEstimator.bodyParts[.rightAnkle]!.location,
poseEstimator.bodyParts[.rightKnee]!.location], size: size)
.stroke(lineWidth: 5.0)
.fill(Color.blue)
}
Circle()
.fill(Color.blue)
.frame(width: 10, height: 10)
.position(CGPoint(x: 0.5, y: 0.5)) // <- this is the circle which I have problems with
if poseEstimator.bodyParts[.rightKnee]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.rightHip]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.root]!.location != CGPoint(x: 0.0, y: 1.0) {
Stick(points: [poseEstimator.bodyParts[.rightKnee]!.location,
poseEstimator.bodyParts[.rightHip]!.location,
poseEstimator.bodyParts[.root]!.location], size: size)
.stroke(lineWidth: 5.0)
.fill(Color.blue)
}
// Left leg
if poseEstimator.bodyParts[.leftAnkle]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.leftKnee]!.location != CGPoint(x: 0.0, y: 1.0){
Stick(points: [poseEstimator.bodyParts[.leftAnkle]!.location,
poseEstimator.bodyParts[.leftKnee]!.location], size: size)
.stroke(lineWidth: 5.0)
.fill(Color.blue)
}
if poseEstimator.bodyParts[.leftKnee]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.leftHip]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.root]!.location != CGPoint(x: 0.0, y: 1.0){
Stick(points: [poseEstimator.bodyParts[.leftKnee]!.location,
poseEstimator.bodyParts[.leftHip]!.location,
poseEstimator.bodyParts[.root]!.location], size: size)
.stroke(lineWidth: 5.0)
.fill(Color.blue)
}
// Right arm
if poseEstimator.bodyParts[.rightWrist]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.rightElbow]!.location != CGPoint(x: 0.0, y: 1.0){
Stick(points: [poseEstimator.bodyParts[.rightWrist]!.location,
poseEstimator.bodyParts[.rightElbow]!.location], size: size)
.stroke(lineWidth: 5.0)
.fill(Color.blue)
}
if poseEstimator.bodyParts[.rightWrist]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.rightElbow]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.neck]!.location != CGPoint(x: 0.0, y: 1.0){
Stick(points: [poseEstimator.bodyParts[.rightElbow]!.location,
poseEstimator.bodyParts[.rightShoulder]!.location,
poseEstimator.bodyParts[.neck]!.location], size: size)
.stroke(lineWidth: 5.0)
.fill(Color.blue)
}
// Left arm
if poseEstimator.bodyParts[.leftWrist]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.leftElbow]!.location != CGPoint(x: 0.0, y: 1.0){
Stick(points: [poseEstimator.bodyParts[.leftWrist]!.location,
poseEstimator.bodyParts[.leftElbow]!.location], size: size)
.stroke(lineWidth: 5.0)
.fill(Color.blue)
}
if poseEstimator.bodyParts[.leftElbow]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.leftShoulder]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.neck]!.location != CGPoint(x: 0.0, y: 1.0){
dot(Position: CGPoint(x: 0.5, y: 0.5), Color: Color.blue)
.position(CGPoint(x: 0.5, y: 0.5))
}
// Root to nose
if poseEstimator.bodyParts[.root]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.neck]!.location != CGPoint(x: 0.0, y: 1.0){
Stick(points: [poseEstimator.bodyParts[.root]!.location,
poseEstimator.bodyParts[.neck]!.location], size: size)
.stroke(lineWidth: 5.0)
.fill(Color.blue)
}
}
}
}
}

Answer 1

Ok I've finally cracked the code. #jnpdx was right, the CGPoint that I set was too small to be even rendered in the first place. Upon further troubleshooting, I found out that the variable poseEstimator.bodyparts[.leftshoulder]!.location that I assigned to the position property of the circle was around 0.3, which was too small to be seen. I had to scale the variable using CGAffineTransform so that the CGpoint was relative to the width and height of the screen. This fixed the problem.
import SwiftUI
#available(iOS 15.0, *)
struct dotview: View { //declare the stickfigure for pose esimation as a swift view
#ObservedObject var poseEstimator: PoseEstimator
var size: CGSize
var body: some View {
if poseEstimator.bodyParts.isEmpty == false { //add in the sticks only if there are VNPoints stored in "bodyparts"
ZStack {
// Right leg
if poseEstimator.bodyParts[.rightAnkle]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.rightKnee]!.location != CGPoint(x: 0.0, y: 1.0){
Circle()
.fill(poseEstimator.rightanklecolor)
.position(poseEstimator.bodyParts[.rightAnkle]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
Circle()
.fill(poseEstimator.rightkneecolor)
.position(poseEstimator.bodyParts[.rightKnee]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
}
if poseEstimator.bodyParts[.rightKnee]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.rightHip]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.root]!.location != CGPoint(x: 0.0, y: 1.0) {
Circle()
.fill(poseEstimator.rightkneecolor)
.position(poseEstimator.bodyParts[.rightKnee]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
Circle()
.fill(poseEstimator.righthipcolor)
.position(poseEstimator.bodyParts[.rightHip]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
}
// Left leg
if poseEstimator.bodyParts[.leftAnkle]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.leftKnee]!.location != CGPoint(x: 0.0, y: 1.0){
Circle()
.fill(poseEstimator.leftanklecolor)
.position(poseEstimator.bodyParts[.leftAnkle]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
Circle()
.fill(poseEstimator.leftkneecolor)
.position(poseEstimator.bodyParts[.leftKnee]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
}
if poseEstimator.bodyParts[.leftKnee]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.leftHip]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.root]!.location != CGPoint(x: 0.0, y: 1.0){
Circle()
.fill(poseEstimator.leftkneecolor)
.position(poseEstimator.bodyParts[.leftKnee]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
Circle()
.fill(poseEstimator.lefthipcolor)
.position(poseEstimator.bodyParts[.leftHip]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
}
// Right arm
if poseEstimator.bodyParts[.rightWrist]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.rightElbow]!.location != CGPoint(x: 0.0, y: 1.0){
Circle()
.fill(poseEstimator.rightwristcolor)
.position(poseEstimator.bodyParts[.rightWrist]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
Circle()
.fill(poseEstimator.rightelbowcolor)
.position(poseEstimator.bodyParts[.rightElbow]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
}
if poseEstimator.bodyParts[.rightElbow]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.rightShoulder]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.neck]!.location != CGPoint(x: 0.0, y: 1.0){
Circle()
.fill(poseEstimator.rightelbowcolor)
.position(poseEstimator.bodyParts[.rightElbow]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
Circle()
.fill(poseEstimator.rightshouldercolor)
.position(poseEstimator.bodyParts[.rightShoulder]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
}
// Left arm
if poseEstimator.bodyParts[.leftWrist]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.leftElbow]!.location != CGPoint(x: 0.0, y: 1.0){
Circle()
.fill(poseEstimator.leftwristcolor)
.position(poseEstimator.bodyParts[.leftWrist]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
Circle()
.fill(poseEstimator.leftelbowcolor)
.position(poseEstimator.bodyParts[.leftElbow]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
}
if poseEstimator.bodyParts[.leftElbow]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.leftShoulder]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.neck]!.location != CGPoint(x: 0.0, y: 1.0){
Circle()
.fill(poseEstimator.leftelbowcolor)
.position(poseEstimator.bodyParts[.leftElbow]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
Circle()
.fill(poseEstimator.leftshouldercolor)
.position(poseEstimator.bodyParts[.leftShoulder]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
}
// Root to nose
if poseEstimator.bodyParts[.root]!.location != CGPoint(x: 0.0, y: 1.0) && poseEstimator.bodyParts[.neck]!.location != CGPoint(x: 0.0, y: 1.0){
Circle()
.fill(poseEstimator.rootcolor)
.position(poseEstimator.bodyParts[.root]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
Circle()
.fill(poseEstimator.neckcolor)
.position(poseEstimator.bodyParts[.neck]!.location.applying(CGAffineTransform.identity.scaledBy(x: size.width, y: size.height)) .applying(CGAffineTransform(scaleX: -1, y: -1).translatedBy(x: -size.width, y: -size.height)))
.frame(width: 15, height: 15)
}
}
}
}
}