Testing the effect of rotation on GeometryReaders

Rotation.swift

import PlaygroundSupport
import SwiftUI

struct ContentView: View {
	@State private var rotation = Angle(degrees: 0)
	
	var body: some View {
		VStack {
			GeometryReader { proxy in
				VStack {
					let localFrame = proxy.frame(in: .local)
					Text("Local: \(localFrame.size.height, format: .number) × \(localFrame.size.width, format: .number)")
					
					let globalFrame = proxy.frame(in: .global)
					Text("Global: \(globalFrame.size.height, format: .number) × \(globalFrame.size.width, format: .number)")
				}
				.frame(maxWidth: .infinity, maxHeight: .infinity)
				.background(Color.teal)
			}
			.rotationEffect(rotation)
			
			Slider(value: $rotation.degrees, in: 0 ... 90)
		}
		.padding()
	}
}

PlaygroundPage.current.setLiveView(
	ContentView()
		.frame(width: 400, height: 400)
)