Files
2020-04-18 20:29:01 +04:00

56 lines
3.5 KiB
Swift

// MIT License
// Copyright (c) 2020 Haik Aslanyan
// 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.
import QuartzCore
struct RCPointMapper {
private var transform: CATransform3D
private let denominatorX: CGFloat
private let denominatorY: CGFloat
private let denominatorW: CGFloat
private let size: CGFloat
init(transform: CATransform3D, size: Int) {
let translateDueToDisposition = CATransform3DMakeTranslation(-CGFloat(size) / 2, -CGFloat(size) / 2, 0)
self.transform = CATransform3DConcat(transform, translateDueToDisposition)
self.size = CGFloat(size)
self.denominatorX = transform.m12 * transform.m21 - transform.m11 * transform.m22 + transform.m14 * transform.m22 * transform.m41 - transform.m12 * transform.m24 * transform.m41 - transform.m14 * transform.m21 * transform.m42 + transform.m11 * transform.m24 * transform.m42
self.denominatorY = -transform.m12 * transform.m21 + transform.m11 * transform.m22 - transform.m14 * transform.m22 * transform.m41 + transform.m12 * transform.m24 * transform.m41 + transform.m14 * transform.m21 * transform.m42 - transform.m11 * transform.m24 * transform.m42
self.denominatorW = transform.m12 * transform.m21 - transform.m11 * transform.m22 + transform.m14 * transform.m22 * transform.m41 - transform.m12 * transform.m24 * transform.m41 - transform.m14 * transform.m21 * transform.m42 + transform.m11 * transform.m24 * transform.m42
}
func map(points: [CGPoint]) -> [CGPoint] {
return points.map { point in
let modelPoint = CGPoint(x: (point.x * 2.0 - size) / 2.0, y: (point.y * 2.0 - size) / 2.0)
let x = modelPoint.x
let y = modelPoint.y
let xp: CGFloat = (transform.m22 * transform.m41 - transform.m21 * transform.m42 - transform.m22 * x + transform.m24 * transform.m42 * x + transform.m21 * y - transform.m24 * transform.m41 * y) / denominatorX
let yp: CGFloat = (-transform.m11 * transform.m42 + transform.m12 * (transform.m41 - x) + transform.m14 * transform.m42 * x + transform.m11 * y - transform.m14 * transform.m41 * y) / denominatorY
let wp: CGFloat = (transform.m12 * transform.m21 - transform.m11 * transform.m22 + transform.m14 * transform.m22 * x - transform.m12 * transform.m24 * x - transform.m14 * transform.m21 * y + transform.m11 * transform.m24 * y) / denominatorW
let actualPoint = CGPoint(x: xp / wp, y: yp / wp)
let isOutOfBounds = !(0...size).contains(actualPoint.x) || !(0...size).contains(actualPoint.y)
return isOutOfBounds ? .zero : actualPoint
}
}
}