SwiftUI Metal Shader changing background color based on mouse position

ContentView.swift

import SwiftUI

struct ContentView: View {
    @State private var hoverLocation: CGPoint = .zero
    @State private var isHovering = false
    @State var toggleText = false

    var body: some View {
        ZStack {
            Rectangle()
                .foregroundStyle(.black)
                .layerEffect(ShaderLibrary.circle(
                    .boundingRect,
                    .float2(hoverLocation)
                ), maxSampleOffset: .zero)
                .blur(radius: 10.0)
        }
        .onContinuousHover { phase in
            switch phase {
            case .active(let location):
                hoverLocation = location
                isHovering = true
            case .ended:
                isHovering = false
            }
        }
        .frame(minWidth: 400, idealWidth: 400, maxWidth: .infinity, minHeight: 400, idealHeight: 400, maxHeight: .infinity, alignment: .center)
    }
}

#Preview {
    ContentView()
}

Shader.metal

#include <metal_stdlib>
using namespace metal;
#include <SwiftUI/SwiftUI_Metal.h>

[[ stitchable ]] half4 circle(float2 position, SwiftUI::Layer layer, float4 bounds, float2 touch) {

    // Normalized pixel coordinates (from 0 to 1)
    float2 st = position/bounds.zw;

    // Normalized touch position
    float m_x = touch.x / bounds.z;
    float m_y = touch.y / bounds.w;

    float3 m_color = float3(0.0);

    float2 dist = float2(m_x, m_y) - st.xy;
    dist.x *= bounds.z/bounds.w;

    // Smoothstep draws the circle
    // 1.0 - ... to from the black to the desired end-rult
    // play around with 0.5 to make the circle smaller or bigger
    float mouse_pct = length(dist);
    mouse_pct = smoothstep(0.1, 1.0, 1. - mouse_pct * 0.5);
    m_color = float3(mouse_pct);

    float3 darkPurple = float3(0.28, 0.06, 0.41);

    // #15011f
    float3 superDarkPurple = float3(0.08, 0.0, 0.12);

    return half4(half3(m_color * darkPurple), 1.0);
}

Here is the is a very small video of it:

background-shader-moving-hover-super-small.mov

And here is a screenshot: