git.r.bdr.sh - rbdr/map/blob - Map/MapRenderComponents/MapEdges.swift

   1 //
   2 //  MapEdges.swift
   3 //  Map
   4 //
   5 //  Created by Ruben Beltran del Rio on 2/2/21.
   6 //
   7
   8 import SwiftUI
   9
  10 struct MapEdges: View {
  11
  12   @Environment(\.colorScheme) var colorScheme
  13
  14   let mapSize: CGSize
  15   let lineWidth: CGFloat
  16   let vertexSize: CGSize
  17   let edges: [MapEdge]
  18
  19   let arrowheadSize = CGFloat(10.0)
  20
  21   var color: Color {
  22     MapColor.colorForScheme(colorScheme).foreground
  23   }
  24
  25   var body: some View {
  26     ForEach(edges, id: \.id) { edge in
  27       Path { path in
  28
  29         // First we transform edges from percentage to map coordinates
  30         let origin = CGPoint(x: w(edge.origin.x), y: h(edge.origin.y))
  31         let destination = CGPoint(x: w(edge.destination.x), y: h(edge.destination.y))
  32
  33         let slope = (destination.y - origin.y) / (destination.x - origin.x)
  34         let angle = atan(slope)
  35         let multiplier = CGFloat(slope < 0 ? -1.0 : 1.0)
  36         let upperAngle = angle - CGFloat.pi / 4.0
  37         let lowerAngle = angle + CGFloat.pi / 4.0
  38
  39         let offsetOrigin = CGPoint(
  40           x: origin.x + multiplier * (vertexSize.width / 2.0) * cos(angle),
  41           y: origin.y + multiplier * (vertexSize.height / 2.0) * sin(angle))
  42         let offsetDestination = CGPoint(
  43           x: destination.x - multiplier * (vertexSize.width / 2.0) * cos(angle),
  44           y: destination.y - multiplier * (vertexSize.height / 2.0) * sin(angle))
  45
  46         path.move(to: offsetOrigin)
  47         path.addLine(to: offsetDestination)
  48
  49         if edge.arrowhead {
  50           path.move(to: offsetDestination)
  51           path.addLine(
  52             to: CGPoint(
  53               x: offsetDestination.x - multiplier * arrowheadSize * cos(upperAngle),
  54               y:
  55                 offsetDestination.y - multiplier * arrowheadSize * sin(upperAngle)))
  56
  57           path.move(to: offsetDestination)
  58           path.addLine(
  59             to: CGPoint(
  60               x: offsetDestination.x - multiplier * arrowheadSize * cos(lowerAngle),
  61               y:
  62                 offsetDestination.y - multiplier * arrowheadSize * sin(lowerAngle)))
  63         }
  64         path.move(to: offsetDestination)
  65         path.closeSubpath()
  66       }.applying(
  67         CGAffineTransform(translationX: vertexSize.width / 2.0, y: vertexSize.height / 2.0)
  68       ).stroke(color, lineWidth: lineWidth)
  69     }
  70   }
  71
  72   func h(_ dimension: CGFloat) -> CGFloat {
  73     max(0.0, min(mapSize.height, dimension * mapSize.height / 100.0))
  74   }
  75
  76   func w(_ dimension: CGFloat) -> CGFloat {
  77     max(0.0, min(mapSize.width, dimension * mapSize.width / 100.0))
  78   }
  79 }
  80
  81 struct MapEdges_Previews: PreviewProvider {
  82   static var previews: some View {
  83     MapEdges(
  84       mapSize: CGSize(width: 400.0, height: 400.0), lineWidth: 1.0,
  85       vertexSize: CGSize(width: 25.0, height: 25.0),
  86       edges: [
  87         MapEdge(
  88           id: 1, origin: CGPoint(x: 2.0, y: 34.0), destination: CGPoint(x: 23.0, y: 76.2),
  89           arrowhead: true)
  90       ])
  91   }
  92 }