import ConcaveHull import SwiftUI struct MapGroup: View { let mapSize: CGSize let vertexSize: CGSize let group: [Vertex] let color: Color let cornerSize = CGSize(width: 2.0, height: 2.0) var strokeSize: CGFloat { 1.75 * vertexSize.width } var hull: [CGPoint] { let groupList = group.map({ vertex in return [Double(vertex.position.x), Double(vertex.position.y)] }) let hull = Hull() let hullPoints = hull.hull(groupList, nil) return hullPoints.compactMap({ object in if let point = object as? [Double] { return CGPoint(x: point[0], y: point[1]) } return nil }) } var body: some View { Path { path in var initialMove: CGPoint? for point in hull { let offsetPoint = CGPoint(x: w(point.x), y: h(point.y)) if initialMove == nil { path.move(to: offsetPoint) initialMove = offsetPoint } else { path.addLine(to: offsetPoint) } } if let initialMove = initialMove { path.addLine(to: initialMove) } } .applying( CGAffineTransform(translationX: vertexSize.width / 2.0, y: vertexSize.height / 2.0) ) .fill(color) .stroke( color, style: StrokeStyle( lineWidth: strokeSize, lineCap: .round, lineJoin: .round, miterLimit: 0, dash: [], dashPhase: 0 ) ) } func h(_ dimension: CGFloat) -> CGFloat { max(0.0, min(mapSize.height, dimension * mapSize.height / 100.0)) } func w(_ dimension: CGFloat) -> CGFloat { max(0.0, min(mapSize.width, dimension * mapSize.width / 100.0)) } } #Preview { MapGroup( mapSize: CGSize(width: 400.0, height: 400.0), vertexSize: CGSize(width: 25.0, height: 25.0), group: [ Vertex(id: 0, label: "A Circle", position: CGPoint(x: 50.0, y: 50.0)), Vertex(id: 1, label: "A Square", position: CGPoint(x: 10.0, y: 20.0), shape: .square), Vertex(id: 2, label: "A triangle", position: CGPoint(x: 25, y: 32.0), shape: .triangle), Vertex(id: 3, label: "An X", position: CGPoint(x: 70.0, y: 70.0), shape: .x), ], color: .red) }