ninjaprox/NVActivityIndicatorView

//
//  NVActivityIndicatorAnimationTriangleSkewSpin.swift
//  NVActivityIndicatorView
//
// The MIT License (MIT)

// Copyright (c) 2016 Vinh Nguyen

// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//

#if canImport(UIKit)
import UIKit

class NVActivityIndicatorAnimationTriangleSkewSpin: NVActivityIndicatorAnimationDelegate {

    func setUpAnimation(in layer: CALayer, size: CGSize, color: UIColor) {
        let x = (layer.bounds.size.width - size.width) / 2
        let y = (layer.bounds.size.height - size.height) / 2
        let duration: CFTimeInterval = 3
        let timingFunction = CAMediaTimingFunction(controlPoints: 0.09, 0.57, 0.49, 0.9)

        // Animation
        let animation = CAKeyframeAnimation(keyPath: "transform")

        animation.keyTimes = [0, 0.25, 0.5, 0.75, 1]
        animation.timingFunctions = [timingFunction, timingFunction, timingFunction, timingFunction]
        animation.values = [
            NSValue(caTransform3D: CATransform3DConcat(createRotateXTransform(angle: 0), createRotateYTransform(angle: 0))),
            NSValue(caTransform3D: CATransform3DConcat(createRotateXTransform(angle: CGFloat(Double.pi)), createRotateYTransform(angle: 0))),
            NSValue(caTransform3D: CATransform3DConcat(createRotateXTransform(angle: CGFloat(Double.pi)), createRotateYTransform(angle: CGFloat(Double.pi)))),
            NSValue(caTransform3D: CATransform3DConcat(createRotateXTransform(angle: 0), createRotateYTransform(angle: CGFloat(Double.pi)))),
            NSValue(caTransform3D: CATransform3DConcat(createRotateXTransform(angle: 0), createRotateYTransform(angle: 0)))
        ]
        animation.duration = duration
        animation.repeatCount = HUGE
        animation.isRemovedOnCompletion = false

        // Draw triangle
        let triangle = NVActivityIndicatorShape.triangle.layerWith(size: size, color: color)

        triangle.frame = CGRect(x: x, y: y, width: size.width, height: size.height)
        triangle.add(animation, forKey: "animation")
        layer.addSublayer(triangle)
    }

    func createRotateXTransform(angle: CGFloat) -> CATransform3D {
        var transform = CATransform3DMakeRotation(angle, 1, 0, 0)

        transform.m34 = CGFloat(-1) / 100

        return transform
    }

    func createRotateYTransform(angle: CGFloat) -> CATransform3D {
        var transform = CATransform3DMakeRotation(angle, 0, 1, 0)

        transform.m34 = CGFloat(-1) / 100

        return transform
    }
}
#endif