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

   1 /*
   2  Copyright (C) 2024 Rubén Beltrán del Río
   3
   4  This program is free software: you can redistribute it and/or modify
   5  it under the terms of the GNU General Public License as published by
   6  the Free Software Foundation, either version 3 of the License, or
   7  (at your option) any later version.
   8
   9  This program is distributed in the hope that it will be useful,
  10  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  GNU General Public License for more details.
  13
  14  You should have received a copy of the GNU General Public License
  15  along with this program. If not, see https://map.tranquil.systems.
  16  */
  17 import SwiftUI
  18
  19 struct MapEdges: View {
  20
  21   let mapSize: CGSize
  22   let lineWidth: CGFloat
  23   let vertexSize: CGSize
  24   let edges: [MapEdge]
  25
  26   let arrowheadSize = CGFloat(10.0)
  27
  28   var body: some View {
  29     ForEach(edges, id: \.id) { edge in
  30       Path { path in
  31
  32         // First we transform edges from percentage to map coordinates
  33         let origin = CGPoint(x: w(edge.origin.x), y: h(edge.origin.y))
  34         let destination = CGPoint(x: w(edge.destination.x), y: h(edge.destination.y))
  35
  36         let slope = (destination.y - origin.y) / (destination.x - origin.x)
  37         let angle = atan(slope)
  38         let multiplier = CGFloat(slope < 0 ? -1.0 : 1.0)
  39         let upperAngle = angle - CGFloat.pi / 4.0
  40         let lowerAngle = angle + CGFloat.pi / 4.0
  41
  42         let offsetOrigin = CGPoint(
  43           x: origin.x + multiplier * (vertexSize.width / 2.0) * cos(angle),
  44           y: origin.y + multiplier * (vertexSize.height / 2.0) * sin(angle))
  45         let offsetDestination = CGPoint(
  46           x: destination.x - multiplier * (vertexSize.width / 2.0) * cos(angle),
  47           y: destination.y - multiplier * (vertexSize.height / 2.0) * sin(angle))
  48
  49         path.move(to: offsetOrigin)
  50         path.addLine(to: offsetDestination)
  51
  52         if edge.arrowhead {
  53           path.move(to: offsetDestination)
  54           path.addLine(
  55             to: CGPoint(
  56               x: offsetDestination.x - multiplier * arrowheadSize * cos(upperAngle),
  57               y:
  58                 offsetDestination.y - multiplier * arrowheadSize * sin(upperAngle)))
  59
  60           path.move(to: offsetDestination)
  61           path.addLine(
  62             to: CGPoint(
  63               x: offsetDestination.x - multiplier * arrowheadSize * cos(lowerAngle),
  64               y:
  65                 offsetDestination.y - multiplier * arrowheadSize * sin(lowerAngle)))
  66         }
  67         path.move(to: offsetDestination)
  68         path.closeSubpath()
  69       }.applying(
  70         CGAffineTransform(translationX: vertexSize.width / 2.0, y: vertexSize.height / 2.0)
  71       ).stroke(Color.map.vertexColor, lineWidth: lineWidth)
  72     }
  73   }
  74
  75   func h(_ dimension: CGFloat) -> CGFloat {
  76     max(0.0, min(mapSize.height, dimension * mapSize.height / 100.0))
  77   }
  78
  79   func w(_ dimension: CGFloat) -> CGFloat {
  80     max(0.0, min(mapSize.width, dimension * mapSize.width / 100.0))
  81   }
  82 }
  83
  84 #Preview {
  85   MapEdges(
  86     mapSize: CGSize(width: 400.0, height: 400.0), lineWidth: 1.0,
  87     vertexSize: CGSize(width: 25.0, height: 25.0),
  88     edges: [
  89       MapEdge(
  90         id: 1, origin: CGPoint(x: 2.0, y: 34.0), destination: CGPoint(x: 23.0, y: 76.2),
  91         arrowhead: true)
  92     ])
  93 }