RandomMap.swift

import UIKit
import simd

let mapWidth: Int32 = 40
let mapHeight: Int32 = 10
var mapString: String = ""
var mapNodes: [SIMD2<Int32>: String] = [:]

struct Node: Hashable {
    let gridPosition: SIMD2<Int32>
}

struct Rectangle {
    let start: SIMD2<Int32>
    var w: Int32
    var h: Int32
}

func makeRoom(at startPosition: SIMD2<Int32>) {
    let roomSize: Int32 = 5
    var rectangle = Rectangle(
        start: startPosition,
        w: (startPosition.x + roomSize),
        h: (startPosition.y + roomSize)
    )
    // Out-of-bounds check. Clips the size of the room
    // to the max size of the underlying map
    if (startPosition.x + roomSize >= mapWidth) {
        let difference = mapWidth - (startPosition.x + roomSize)
        rectangle.w -= difference
    }
    if (startPosition.y + roomSize >= mapHeight) {
        let difference = mapHeight - (startPosition.y + roomSize)
        rectangle.h -= difference
    }
    
    for x in startPosition.x..<rectangle.w {
        for y in startPosition.y..<rectangle.h {
            let node = Node(gridPosition: SIMD2<Int32>(x,y))
            mapNodes.updateValue(".", forKey: node.gridPosition)
        }
    }
}

// MAKE FLOOR
func makeFloor() {
    for y in 0..<mapHeight {
        for x in 0..<mapWidth {
            let node = Node(gridPosition: SIMD2<Int32>(x,y))
            mapNodes.updateValue("#", forKey: node.gridPosition)
        }
    }
}

// MAKE BOUNDARIES
func makeBoundaries() {
    var position = SIMD2<Int32>(0,0)
    // Upper boundary
    for key in mapNodes.keys {
        position.x = key.x
        mapNodes[position] = "#"
    }
    // Lower boundary
    for key in mapNodes.keys {
        position.x = key.x
        position.y = mapHeight - 1
        mapNodes[position] = "#"
    }
    // Left boundary
    for key in mapNodes.keys {
        position.x = 0
        position.y = key.y
        mapNodes[position] = "#"
    }
    // Right boundary
    for key in mapNodes.keys {
        position.x = mapWidth - 1
        position.y = key.y
        mapNodes[position] = "#"
    }
}

// RENDER NODES
func renderMap() {
    for y in 0..<mapHeight {
        for x in 0..<mapWidth {
            let position = SIMD2<Int32>(x,y)
            if let nodeFound = mapNodes[position] {
                mapString.append(nodeFound)
            }
        }
        mapString.append("\n")
    }
}

// BUILD MAP
func buildBaseMap(numberOfRooms: Int){
    makeFloor()
    
    for _ in 0..<numberOfRooms {
        let randX = Int32.random(in: 0..<mapWidth)
        let randY = Int32.random(in: 0..<mapHeight)
        makeRoom(at: SIMD2<Int32>(randX,randY))
    }
    makeBoundaries()
    renderMap()
    print("Nodes: \(mapNodes.count)")
    print(mapString)
}

buildBaseMap(numberOfRooms: 10)