git.r.bdr.sh - rbdr/map/blob - Map/Presentation/Base Components/MapRender/MapEdges.swift

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