Day 1 collision detection: swift 3 - swift

Question

So I want a game made, this was striped from the Xcode SpriteKit sampler, pretty simple. It will evolve greatly as I get this key issue out of the way. It has a player, Wall's, and a door. Nodes are assigned, player works fine. Wall's attempted for children in self, but crashes with my comments removed. I have a guess as multiple nodes of same name? But the door, when assigned node, for some reason no matter what slowly falls, with no gravity ticked and no gravity coded.
Those are lesser concerns. I come to you today to pick at why my collisions might not be activating my collision argument functions, to enter the house.
Yes I am aware it says contact mapped to the event. It suits my theory I am pretty sure.
//
// GameScene.swift
// Sandbox
//
// Created by M on 7/1/16.
// Copyright © 2016 M. All rights reserved.
//
import SpriteKit
import GameplayKit
class GameScene: SKScene, SKPhysicsContactDelegate {
var entities = [GKEntity]()
var graphs = [GKGraph]()
private var lastUpdateTime : TimeInterval = 0
private var label : SKLabelNode?
var playerNode : SKSpriteNode?
var wallNode : SKSpriteNode?
var doorNode : SKSpriteNode?
private var spinnyNode : SKShapeNode?
var furnishing : SKSpriteNode?
var playerCategory = 0x1 << 0
var wallCategory = 0x1 << 1
var doorCategory = 0x1 << 2
var pathCategory = 0x1 << 3
func nextRoom() {
let sceneNode = SKScene(fileNamed: "MyScene")
sceneNode?.scaleMode = .aspectFill
// Present the scene
if let view = self.view {
view.presentScene(sceneNode)
view.ignoresSiblingOrder = true
view.showsFPS = true
view.showsNodeCount = true
}
}
func loadRoom() {
let furnishing = SKSpriteNode(color: #colorLiteral(red: 0.2464724183, green: 0.05352632701, blue: 0.03394328058, alpha: 1), size:CGSize(width:25, height:25))
doorNode?.addChild(furnishing)
}
func enterHouse() {
let newWindow = CGSize(width: 500, height: 500)
doorNode?.scale(to: newWindow)
loadRoom()
}
func exitHouse(){
let oldWindow = CGSize(width: 100, height: 100)
doorNode?.scale(to: oldWindow)
}
override func sceneDidLoad() {
self.lastUpdateTime = 0
physicsWorld.contactDelegate = self
// Get nodes from scene and store for use later
self.playerNode = self.childNode(withName: "//player") as? SKSpriteNode
playerNode?.physicsBody = SKPhysicsBody(rectangleOf: (playerNode?.frame.size)!)
playerNode?.physicsBody?.isDynamic = true
playerNode?.physicsBody?.affectedByGravity = false
playerNode?.physicsBody?.categoryBitMask = UInt32(playerCategory)
playerNode?.physicsBody?.collisionBitMask = UInt32(wallCategory)
playerNode?.physicsBody?.contactTestBitMask = UInt32(doorCategory)
for child in self.children {
/*if child.name == "wall" {
if let child = child as? SKSpriteNode {
wallNode?.physicsBody = SKPhysicsBody(rectangleOf: (wallNode?.frame.size)!)
wallNode?.physicsBody?.isDynamic = false
wallNode?.physicsBody?.categoryBitMask = UInt32(wallCategory)
wallNode?.physicsBody?.collisionBitMask = UInt32(playerCategory)
self.addChild(child)
}
}*/
}
self.doorNode = self.childNode(withName: "door") as? SKSpriteNode
doorNode?.physicsBody?.affectedByGravity = false
doorNode?.physicsBody?.isDynamic = false
doorNode?.physicsBody = SKPhysicsBody(rectangleOf: (doorNode?.frame.size)!)
doorNode?.physicsBody?.categoryBitMask = UInt32(doorCategory)
doorNode?.physicsBody?.contactTestBitMask = UInt32(playerCategory)
}
func touchDown(atPoint pos : CGPoint) {
let fromX = playerNode?.position.x
let fromY = playerNode?.position.y
let toX = pos.x
let toY = pos.y
let resultX = toX - (fromX)!
let resultY = toY - (fromY)!
let newX = (playerNode?.position.x)! + resultX / 10
let newY = (playerNode?.position.y)! + resultY / 10
playerNode?.position.x = newX
playerNode?.position.y = newY
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for t in touches { self.touchDown(atPoint: t.location(in: self)) }
}
func didBeginContact(contact: SKPhysicsContact) {
//this gets called automatically when two objects begin contact with each other
// 1. Create local variables for two physics bodies
var firstBody: SKPhysicsBody
var secondBody: SKPhysicsBody
// 2. Assign the two physics bodies so that the one with the lower category is always stored in firstBody
if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
firstBody = contact.bodyA
secondBody = contact.bodyB
} else {
firstBody = contact.bodyB
secondBody = contact.bodyA
}
if secondBody.categoryBitMask == UInt32(doorCategory){
enterHouse()
}
}
override func update(_ currentTime: TimeInterval) {
// Called before each frame is rendered
// Initialize _lastUpdateTime if it has not already been
if (self.lastUpdateTime == 0) {
self.lastUpdateTime = currentTime
}
// Calculate time since last update
let dt = currentTime - self.lastUpdateTime
// Update entities
for entity in self.entities {
entity.update(withDeltaTime: dt)
}
self.lastUpdateTime = currentTime
}
}

Answer 1

I presume this line is causing the crash
wallNode?.physicsBody = SKPhysicsBody(rectangleOf: (wallNode?.frame.size)!)
as you are force unwrapping (!) the wallNode size however looking at your code you never assign it to anything like so
wallNode = self.childNode(withName: "wallNode") as? SKSpriteNode
or in the for loop.
Try this code in your for in loop that should avoid crashes and assigns your wall node.
for child in self.children where child.name == "wall" {
if let child = child as? SKSpriteNode {
wallNode = child // Try this
if let wallNode = wallNode { // safely unwrap wall node to avoid crashes
wallNode.physicsBody = SKPhysicsBody(rectangleOf: (wallNode.frame.size))
wallNode.physicsBody?.isDynamic = false
wallNode.physicsBody?.categoryBitMask = UInt32(wallCategory)
wallNode.physicsBody?.collisionBitMask = UInt32(playerCategory)
self.addChild(wallNode) // add wall node here instead if you are using your wallNode property
}
}
}
Hope this helps