Dan WoodandDan Wood
51db5a067a
* Starting on filling in documentation. * First pass on most/all files * more descriptions filled in * Some documentation but TBH the author would be better suited to explain how this works! * more basic stuff filled in * Add a description and bunch of discussion text for most of the view `body` declarations * more explanations Co-authored-by: Dan Wood <danwood@users.noreply.github.com>
477 lines
16 KiB
Swift
477 lines
16 KiB
Swift
import SwiftUI
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extension Path {
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/// Returns a tiny segment of path based on percentage along the path
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///
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/// TODO: Explain why more than 1 gets 0 and why less than 0 gets 1
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/// - Parameter percent: fraction along data set, between 0.0 and 1.0 (underflow and overflow are handled)
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/// - Returns: tiny path right around the requested fraction
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func trimmedPath(for percent: CGFloat) -> Path {
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let boundsDistance: CGFloat = 0.001
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let completion: CGFloat = 1 - boundsDistance
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let pct = percent > 1 ? 0 : (percent < 0 ? 1 : percent)
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// Start/end points centered around given percentage, but capped if right at the very end
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let start = pct > completion ? completion : pct - boundsDistance
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let end = pct > completion ? 1 : pct + boundsDistance
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return trimmedPath(from: start, to: end)
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}
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/// Find the `CGPoint` for the given fraction along the path.
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///
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/// This works by requesting a very tiny trimmed section of the path, then getting the center of the bounds rectangle
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/// - Parameter percent: fraction along data set, between 0.0 and 1.0 (underflow and overflow are handled)
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/// - Returns: a `CGPoint` representing the location of that section of the path
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func point(for percent: CGFloat) -> CGPoint {
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let path = trimmedPath(for: percent)
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return CGPoint(x: path.boundingRect.midX, y: path.boundingRect.midY)
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}
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/// <#Description#>
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/// - Parameter maxX: <#maxX description#>
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/// - Returns: <#description#>
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func point(to maxX: CGFloat) -> CGPoint {
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let total = length
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let sub = length(to: maxX)
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let percent = sub / total
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return point(for: percent)
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}
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/// <#Description#>
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/// - Returns: <#description#>
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var length: CGFloat {
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var ret: CGFloat = 0.0
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var start: CGPoint?
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var point = CGPoint.zero
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forEach { ele in
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switch ele {
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case .move(let to):
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if start == nil {
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start = to
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}
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point = to
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case .line(let to):
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ret += point.line(to: to)
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point = to
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case .quadCurve(let to, let control):
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ret += point.quadCurve(to: to, control: control)
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point = to
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case .curve(let to, let control1, let control2):
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ret += point.curve(to: to, control1: control1, control2: control2)
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point = to
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case .closeSubpath:
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if let to = start {
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ret += point.line(to: to)
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point = to
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}
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start = nil
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}
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}
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return ret
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}
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/// <#Description#>
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/// - Parameter maxX: <#maxX description#>
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/// - Returns: <#description#>
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func length(to maxX: CGFloat) -> CGFloat {
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var ret: CGFloat = 0.0
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var start: CGPoint?
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var point = CGPoint.zero
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var finished = false
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forEach { ele in
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if finished {
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return
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}
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switch ele {
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case .move(let to):
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if to.x > maxX {
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finished = true
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return
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}
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if start == nil {
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start = to
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}
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point = to
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case .line(let to):
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if to.x > maxX {
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finished = true
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ret += point.line(to: to, x: maxX)
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return
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}
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ret += point.line(to: to)
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point = to
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case .quadCurve(let to, let control):
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if to.x > maxX {
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finished = true
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ret += point.quadCurve(to: to, control: control, x: maxX)
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return
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}
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ret += point.quadCurve(to: to, control: control)
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point = to
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case .curve(let to, let control1, let control2):
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if to.x > maxX {
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finished = true
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ret += point.curve(to: to, control1: control1, control2: control2, x: maxX)
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return
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}
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ret += point.curve(to: to, control1: control1, control2: control2)
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point = to
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case .closeSubpath:
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fatalError("Can't include closeSubpath")
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}
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}
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return ret
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}
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/// <#Description#>
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/// - Parameters:
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/// - points: <#points description#>
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/// - step: <#step description#>
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/// - globalOffset: <#globalOffset description#>
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/// - Returns: <#description#>
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static func quadCurvedPathWithPoints(points: [Double], step: CGPoint, globalOffset: Double? = nil) -> Path {
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var path = Path()
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if points.count < 2 {
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return path
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}
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let offset = globalOffset ?? points.min()!
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// guard let offset = points.min() else { return path }
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var point1 = CGPoint(x: 0, y: CGFloat(points[0]-offset)*step.y)
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path.move(to: point1)
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for pointIndex in 1..<points.count {
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let point2 = CGPoint(x: step.x * CGFloat(pointIndex), y: step.y*CGFloat(points[pointIndex]-offset))
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let midPoint = CGPoint.midPointForPoints(firstPoint: point1, secondPoint: point2)
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path.addQuadCurve(to: midPoint, control: CGPoint.controlPointForPoints(firstPoint: midPoint, secondPoint: point1))
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path.addQuadCurve(to: point2, control: CGPoint.controlPointForPoints(firstPoint: midPoint, secondPoint: point2))
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point1 = point2
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}
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return path
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}
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/// <#Description#>
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/// - Parameters:
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/// - points: <#points description#>
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/// - step: <#step description#>
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/// - globalOffset: <#globalOffset description#>
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/// - Returns: <#description#>
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static func quadClosedCurvedPathWithPoints(points: [Double], step: CGPoint, globalOffset: Double? = nil) -> Path {
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var path = Path()
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if points.count < 2 {
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return path
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}
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let offset = globalOffset ?? points.min()!
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// guard let offset = points.min() else { return path }
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path.move(to: .zero)
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var point1 = CGPoint(x: 0, y: CGFloat(points[0]-offset)*step.y)
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path.addLine(to: point1)
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for pointIndex in 1..<points.count {
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let point2 = CGPoint(x: step.x * CGFloat(pointIndex), y: step.y*CGFloat(points[pointIndex]-offset))
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let midPoint = CGPoint.midPointForPoints(firstPoint: point1, secondPoint: point2)
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path.addQuadCurve(to: midPoint, control: CGPoint.controlPointForPoints(firstPoint: midPoint, secondPoint: point1))
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path.addQuadCurve(to: point2, control: CGPoint.controlPointForPoints(firstPoint: midPoint, secondPoint: point2))
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point1 = point2
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}
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path.addLine(to: CGPoint(x: point1.x, y: 0))
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path.closeSubpath()
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return path
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}
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/// <#Description#>
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/// - Parameters:
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/// - points: <#points description#>
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/// - step: <#step description#>
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/// - Returns: <#description#>
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static func linePathWithPoints(points: [Double], step: CGPoint) -> Path {
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var path = Path()
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if points.count < 2 {
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return path
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}
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guard let offset = points.min() else {
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return path
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}
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let point1 = CGPoint(x: 0, y: CGFloat(points[0]-offset)*step.y)
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path.move(to: point1)
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for pointIndex in 1..<points.count {
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let point2 = CGPoint(x: step.x * CGFloat(pointIndex), y: step.y*CGFloat(points[pointIndex]-offset))
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path.addLine(to: point2)
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}
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return path
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}
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/// <#Description#>
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/// - Parameters:
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/// - points: <#points description#>
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/// - step: <#step description#>
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/// - Returns: <#description#>
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static func closedLinePathWithPoints(points: [Double], step: CGPoint) -> Path {
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var path = Path()
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if points.count < 2 {
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return path
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}
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guard let offset = points.min() else {
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return path
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}
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var point1 = CGPoint(x: 0, y: CGFloat(points[0]-offset)*step.y)
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path.move(to: point1)
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for pointIndex in 1..<points.count {
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point1 = CGPoint(x: step.x * CGFloat(pointIndex), y: step.y*CGFloat(points[pointIndex]-offset))
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path.addLine(to: point1)
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}
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path.addLine(to: CGPoint(x: point1.x, y: 0))
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path.closeSubpath()
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return path
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}
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}
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extension CGPoint {
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/// <#Description#>
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/// - Parameters:
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/// - to: <#to description#>
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/// - x: <#x description#>
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/// - Returns: <#description#>
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func point(to: CGPoint, x: CGFloat) -> CGPoint {
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let a = (to.y - self.y) / (to.x - self.x)
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let y = self.y + (x - self.x) * a
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return CGPoint(x: x, y: y)
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}
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/// <#Description#>
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/// - Parameter to: <#to description#>
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/// - Returns: <#description#>
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func line(to: CGPoint) -> CGFloat {
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dist(to: to)
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}
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/// <#Description#>
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/// - Parameters:
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/// - to: <#to description#>
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/// - x: <#x description#>
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/// - Returns: <#description#>
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func line(to: CGPoint, x: CGFloat) -> CGFloat {
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dist(to: point(to: to, x: x))
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}
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/// <#Description#>
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/// - Parameters:
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/// - to: <#to description#>
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/// - control: <#control description#>
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/// - Returns: <#description#>
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func quadCurve(to: CGPoint, control: CGPoint) -> CGFloat {
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var dist: CGFloat = 0
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let steps: CGFloat = 100
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for i in 0..<Int(steps) {
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let t0 = CGFloat(i) / steps
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let t1 = CGFloat(i+1) / steps
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let a = point(to: to, t: t0, control: control)
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let b = point(to: to, t: t1, control: control)
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dist += a.line(to: b)
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}
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return dist
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}
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/// <#Description#>
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/// - Parameters:
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/// - to: <#to description#>
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/// - control: <#control description#>
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/// - x: <#x description#>
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/// - Returns: <#description#>
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func quadCurve(to: CGPoint, control: CGPoint, x: CGFloat) -> CGFloat {
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var dist: CGFloat = 0
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let steps: CGFloat = 100
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for i in 0..<Int(steps) {
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let t0 = CGFloat(i) / steps
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let t1 = CGFloat(i+1) / steps
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let a = point(to: to, t: t0, control: control)
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let b = point(to: to, t: t1, control: control)
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if a.x >= x {
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return dist
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} else if b.x > x {
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dist += a.line(to: b, x: x)
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return dist
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} else if b.x == x {
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dist += a.line(to: b)
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return dist
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}
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dist += a.line(to: b)
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}
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return dist
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}
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/// <#Description#>
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/// - Parameters:
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/// - to: <#to description#>
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/// - t: <#t description#>
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/// - control: <#control description#>
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/// - Returns: <#description#>
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func point(to: CGPoint, t: CGFloat, control: CGPoint) -> CGPoint {
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let x = CGPoint.value(x: self.x, y: to.x, t: t, c: control.x)
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let y = CGPoint.value(x: self.y, y: to.y, t: t, c: control.y)
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return CGPoint(x: x, y: y)
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}
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/// <#Description#>
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/// - Parameters:
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/// - to: <#to description#>
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/// - control1: <#control1 description#>
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/// - control2: <#control2 description#>
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/// - Returns: <#description#>
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func curve(to: CGPoint, control1: CGPoint, control2: CGPoint) -> CGFloat {
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var dist: CGFloat = 0
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let steps: CGFloat = 100
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for i in 0..<Int(steps) {
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let t0 = CGFloat(i) / steps
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let t1 = CGFloat(i+1) / steps
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let a = point(to: to, t: t0, control1: control1, control2: control2)
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let b = point(to: to, t: t1, control1: control1, control2: control2)
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dist += a.line(to: b)
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}
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return dist
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}
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/// <#Description#>
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/// - Parameters:
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/// - to: <#to description#>
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/// - control1: <#control1 description#>
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/// - control2: <#control2 description#>
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/// - x: <#x description#>
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/// - Returns: <#description#>
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func curve(to: CGPoint, control1: CGPoint, control2: CGPoint, x: CGFloat) -> CGFloat {
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var dist: CGFloat = 0
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let steps: CGFloat = 100
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for i in 0..<Int(steps) {
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let t0 = CGFloat(i) / steps
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let t1 = CGFloat(i+1) / steps
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let a = point(to: to, t: t0, control1: control1, control2: control2)
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let b = point(to: to, t: t1, control1: control1, control2: control2)
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if a.x >= x {
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return dist
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} else if b.x > x {
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dist += a.line(to: b, x: x)
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return dist
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} else if b.x == x {
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dist += a.line(to: b)
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return dist
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}
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dist += a.line(to: b)
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}
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return dist
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}
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/// <#Description#>
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/// - Parameters:
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/// - to: <#to description#>
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/// - t: <#t description#>
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/// - control1: <#control1 description#>
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/// - control2: <#control2 description#>
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/// - Returns: <#description#>
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func point(to: CGPoint, t: CGFloat, control1: CGPoint, control2: CGPoint) -> CGPoint {
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let x = CGPoint.value(x: self.x, y: to.x, t: t, control1: control1.x, control2: control2.x)
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let y = CGPoint.value(x: self.y, y: to.y, t: t, control1: control1.y, control2: control2.x)
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return CGPoint(x: x, y: y)
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}
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/// <#Description#>
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/// - Parameters:
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/// - x: <#x description#>
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/// - y: <#y description#>
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/// - t: <#t description#>
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/// - c: <#c description#>
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/// - Returns: <#description#>
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static func value(x: CGFloat, y: CGFloat, t: CGFloat, c: CGFloat) -> CGFloat {
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var value: CGFloat = 0.0
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// (1-t)^2 * p0 + 2 * (1-t) * t * c1 + t^2 * p1
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value += pow(1-t, 2) * x
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value += 2 * (1-t) * t * c
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value += pow(t, 2) * y
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return value
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}
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/// <#Description#>
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/// - Parameters:
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/// - x: <#x description#>
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/// - y: <#y description#>
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/// - t: <#t description#>
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/// - control1: <#control1 description#>
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/// - control2: <#control2 description#>
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/// - Returns: <#description#>
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static func value(x: CGFloat, y: CGFloat, t: CGFloat, control1: CGFloat, control2: CGFloat) -> CGFloat {
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var value: CGFloat = 0.0
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// (1-t)^3 * p0 + 3 * (1-t)^2 * t * c1 + 3 * (1-t) * t^2 * c2 + t^3 * p1
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value += pow(1-t, 3) * x
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value += 3 * pow(1-t, 2) * t * control1
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value += 3 * (1-t) * pow(t, 2) * control2
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value += pow(t, 3) * y
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return value
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}
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/// <#Description#>
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/// - Parameters:
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/// - point1: <#point1 description#>
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/// - point2: <#point2 description#>
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/// - Returns: <#description#>
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static func getMidPoint(point1: CGPoint, point2: CGPoint) -> CGPoint {
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return CGPoint(
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x: point1.x + (point2.x - point1.x) / 2,
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y: point1.y + (point2.y - point1.y) / 2
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)
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}
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/// <#Description#>
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/// - Parameter to: <#to description#>
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/// - Returns: <#description#>
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func dist(to: CGPoint) -> CGFloat {
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return sqrt((pow(self.x - to.x, 2) + pow(self.y - to.y, 2)))
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}
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/// <#Description#>
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/// - Parameters:
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/// - firstPoint: <#firstPoint description#>
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/// - secondPoint: <#secondPoint description#>
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/// - Returns: <#description#>
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static func midPointForPoints(firstPoint: CGPoint, secondPoint: CGPoint) -> CGPoint {
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return CGPoint(
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x: (firstPoint.x + secondPoint.x) / 2,
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y: (firstPoint.y + secondPoint.y) / 2)
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}
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/// <#Description#>
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/// - Parameters:
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/// - firstPoint: <#firstPoint description#>
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/// - secondPoint: <#secondPoint description#>
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/// - Returns: <#description#>
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static func controlPointForPoints(firstPoint: CGPoint, secondPoint: CGPoint) -> CGPoint {
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var controlPoint = CGPoint.midPointForPoints(firstPoint: firstPoint, secondPoint: secondPoint)
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let diffY = abs(secondPoint.y - controlPoint.y)
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if firstPoint.y < secondPoint.y {
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controlPoint.y += diffY
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} else if firstPoint.y > secondPoint.y {
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controlPoint.y -= diffY
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}
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return controlPoint
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}
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}
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