HuggingChat-Mac/Animations/Ripple/RippleModifier.swift

//
//  RippleModifier.swift
//  HuggingChat-Mac
//
//  Created by Cyril Zakka on 8/28/24.
//

import SwiftUI

/* See the LICENSE at the end of the article for this sample's licensing information. */

/// A modifier that applies a ripple effect to its content.
struct RippleModifier: ViewModifier {
    var origin: CGPoint

    var elapsedTime: TimeInterval

    var duration: TimeInterval

    var amplitude: Double
    var frequency: Double
    var decay: Double
    var speed: Double

    func body(content: Content) -> some View {
        let shader = ShaderLibrary.Ripple(
            .float2(origin),
            .float(elapsedTime),

            // Parameters
            .float(amplitude),
            .float(frequency),
            .float(decay),
            .float(speed)
        )

        let maxSampleOffset = maxSampleOffset
        let elapsedTime = elapsedTime
        let duration = duration

        content.visualEffect { view, _ in
            view.layerEffect(
                shader,
                maxSampleOffset: maxSampleOffset,
                isEnabled: 0 < elapsedTime && elapsedTime < duration
            )
        }
    }

    var maxSampleOffset: CGSize {
        CGSize(width: amplitude, height: amplitude)
    }
}