Background: I'm creating a game where two objects(Tanks) battle one another.
On the main menu screen, you choose the two Tanks that will be fighting one another (out of a list of 10 different tanks).
The algorithms for moving and firing the individual/specific Tanks comes from a separate .swift (helper) class for each player that can be chosen from the menu.
(there is no user interaction - all of the code for the battle is inside these classes)
Inside the individual player classes there are only two functions defined: player1TankMove() and player2TankMove().
class Player1: gameSceneDelegate {
func player1TankMove() {
// some code that defines the movement and shooting of the Tank
}
func player2TankMove() {
// some code that defines the movement and shooting of the Tank
}
}
There would be ten of these classes (Player1, Player2, Player3...) where the player1TankMove() methods for each class would be completely different from one another.
As you can see, I'm using a delegate from the GameScene to connect the TankMove() functions so that they can be used inside that class:
protocol gameSceneDelegate {
func player1TankMove()
func player2TankMove()
}
class GameScene: SKScene, SKPhysicsContactDelegate { ... //entire GameScene code
My question is, how do I set the proper class when I transition from the MainMenuViewController to the GameScene class?
Would I use lazy instantiation? If so, how would I declare it 'lazily' if I don't know which class/swift file (Player1.swift, Player2.swift, etc.) I'll be accessing?
Is there a better way to do this?
Currently I can access the proper player1TankMove() function and the tank works properly:
var tank1 = Player1()
tank1.player1TankMove() // used inside the update() function
However, because tank1 needs to be an instance of a specific class that is unknown, I'm unsure of how to decide the type to declare. Would I need to use a typealias? Generics? It seems like this would be a fairly common problem that I know how to handle with other languages, but I'm not sure how to code it in Swift.
Related
A simple task. I have a ScoreController which will set the score to UI. I have a UI label that has ScoreView in it
The question is how do I get this ScoreView in my controller
I have found out the way to get View from prefab that's being instantiated:
public class CellViewFactory : ICellViewFactory
{
public ICellView GetView(Vector3 position)
{
var prefab = Resources.Load<GameObject>("Cell");
var instance = UnityEngine.Object.Instantiate(prefab);
var cellView = instance.GetComponent<ICellView>();
cellView.SetPosition(position);
return cellView;
}
}
But since UI isn't instantiated by the code, what's the way to get the ScoreView from it?
Now, I have found an option to call a static method of a Factory and pass self to the method. Smth like this:
public class ScoreView : MonoBehaviour
{
void Start()
{
ScoreViewFactory.NotifyScoreViewCreated(this);
}
}
But it doesn't seem to be flexible using static methods in decoupled code with Factories and interfaces. Hope there's another way
I would also be glad if you post some complete tutorioal on MVC in Unity. Seems that there's no complete working tutorials.
It would also be great if you would share an example of MVC pattern in Unity using DependencyInjection.
I search a lot but couldn't find any answer. My problem: I instantiate several Gameobjects of a Prefab, each consists of two child objects: an obstacle and a scorezone. I want to destroy the scorezone (only of that specific instance), when the player touches the obstacle. So in Runtime my hierarchy looks like this:
-ObjectPrefab(clone)
---Scorezone
---Obstacle
-ObjectPrefab(Clone)
---Scorezone
---Obstacle
...
So I need to find ONE child gameobject (not the Transform) to then destroy it. I tried several codes but none worked. Here is the code with the three alternatives I tried, but none of them worked.:
private void OnCollisionEnter2D(Collision2D collision) {
if (collision.gameObject.tag == "obstacle") {
Alternative 1:
Destroy(GameObject.FindWithTag("scorezone"));
Alternative 1 comes really close, but it destroys all scorezones of all instantiated objects.
Alternative 2:
Destroy(collision.gameObject.transform.parent.gameObject.FindWithTag("scorezone"));
Alternative 2 would sound logic to me but I get the error message "Transform does not contain a definition for "FindWithTag".
Alternative 3:
foreach (Transform child in collision.gameObject.transform)
{
if (child.tag == "scorezone")
{
Destroy(child.gameObject);
}
}
}
Alternative 3 does not give an error but actually does nothing at all when the player hits the obstacle.
I really appreciate some help, thanks in advance!
Store the reference!
If it is really a "prefab" so meaning you have it as an asset and instantiate it on runtime the best way (in my eyes and performance wise) would actually be to use a serialized field:
// Put this component on your obstacle
public class ObjectController : MonoBehaviour
{
// Drag the according object here via the Inspector in the prefab
// => when the prefab is Instantiated this field is already referenced
[SerializeField] private GameObject _scoreZone;
// Read-only access to the reference
public GameObject ScoreZone => _scoreZone;
}
This field reference is stored together with your prefab asset. So every instance of the prefab already has its own child references set up.
and then do
private void OnCollisionEnter2D(Collision2D collision)
{
// Rather use CompareTag which is slightly more efficient
// and adds some security (== silently fails if typo, CompareTag throws an exception instead)
if (collision.gameObject.CompareTag("obstacle"))
{
var controller = collision.gameObject.GetComponent<ObjectController>();
if(controller)
{
Destroy(controller.ScoreZone);
}
}
}
By Index
Alternatively but error prone you could simply use the index. You already know that there are only 2 childs, the first one being the Scorezone with index 0 so you can also do
if (collision.gameObject.CompareTag("obstacle"))
{
var scoreZone = collision.transform.parent.GetChild(0);
Destroy(scoreZone);
}
By Name
Using the name you could also use Find - I would not recommend this! It is error prone and slow
if (collision.gameObject.CompareTag("obstacle"))
{
var scoreZone = collision.transform.parent.Find("ScoreZone");
Destroy(scoreZone);
}
I was coding a very simple program that lets you move around a circle, with also a rectangle in the stage. I wanted to make the circle get in front of the rectangle while you are dragging it, but when you released the mouse, the circle would be sent back.
I don't know how to set a public variable using the getChildIndex method. I don't really care about the rest of the code. I'm mainly interested in how can I make the getChildIndex method work with a public variable.
package code
{
import flash.display.MovieClip;
import flash.events.MouseEvent;
import flash.events.Event;
import flash.display.Sprite;
public class Main extends MovieClip
{
public var myCircleIndex:int = getChildIndex(myCircle);
public function Main()
{
myCircle.addEventListener(MouseEvent.MOUSE_DOWN, mouseClicking);
stage.addEventListener(MouseEvent.MOUSE_UP, mouseReleased);
}
public function mouseClicking(e:MouseEvent): void
{
myCircle.startDrag();
setChildIndex(myCircle, numChildren-1);
}
public function mouseReleased(e:MouseEvent): void
{
myCircle.stopDrag();
setChildIndex(myCircle, myCircleIndex);
}
}
}
I'm using an instance ("myCircle") that I created directly in the stage as a movie clip.
The problem is in the public var I set at the beginning, it doesn't let me get the child index of myCircle, but if I put the same line inside a function, it works.
I know I could directly put the index number of myCircle in the last line (and erasing the public var myCircleIndex), but I figured out that there would be a way of using the getChildIndex for a public var in a class.
How do you use getChildIndex in a public variable inside a class?
The reason it doesn't work, is because your timeline objects don't yet exist when the line public var myCircleIndex:int runs.
You shouldn't try and access non-primitive objects in your class level variable declarations for this very reason, as nothing else in the class is available yet when those vars are created.
Here is how you can refactor this (see the code comments):
public class Main extends MovieClip
{
public var myCircleIndex:int; //just create the reference here, don't assign it
public var myCircle:flash.display.DisplayObject; //this line is just for better compile time checking and code completion, completely optional
public function Main()
{
//wait for all the display stuff to be created before trying to access it. The constructor function can run before timeline stuff is created, so it's not safe to reference stage or timeline objects here.
if(!stage){
this.addEventListener(Event.ADDED_TO_STAGE, timelineCreated);
}else {
timelineCreated(null);
}
}
private function timelineCreated(e:Event):void {
//now that we're certain the timeline stuff has been created, we can reference timeline objects and stage:
//store the initial z-index of myCircle
myCircleIndex = getChildIndex(myCircle);
//the rest of your code that was in the construction -Main()- before
myCircle.addEventListener(MouseEvent.MOUSE_DOWN, mouseClicking);
stage.addEventListener(MouseEvent.MOUSE_UP, mouseReleased);
}
//no change to any of the following stuff
public function mouseClicking(e:MouseEvent): void
{
myCircle.startDrag();
setChildIndex(myCircle, numChildren-1);
}
public function mouseReleased(e:MouseEvent): void
{
myCircle.stopDrag();
setChildIndex(myCircle, myCircleIndex);
}
}
All you need to do to put the circle behind the square is on release do addChild(myRectangle) or addChildAt(myCircle, 0);
You are overcomplicating things by trying to track a variable in my opinion. Let flash sort it out behind the scenes.
If you want a little more finesse and want to just put the circle directly behind the square (if there were 100 layers and the square is at level 12, but you aren't sure which level the square is at) you could do
addChildAt(myCircle, getChildIndex(myRectangle)-1);
note
setChildIndex(myCircle, numChildren-1);
That's fine to do it that way. The more common way to do this is just
addChild(myCircle);
It does the exact same thing. Many people are confused by this thinking this would add a new myCircle but it just brings it to the front if it's already in the display list, and if it's not in the display list, it adds it to the display list at the top z-order (numChildren-1).
I am currently building a game and I want to use Gameplaykit to organise the elements.
I discovered the concept of ECS (Entity Component System) that enables to put functionality in small blocks (called components) that can than be added to an entity to give it functionality.
I would like to use it combined with SpriteKit, my first idea was of course to create a SpriteComponent, but since I am also using the physics engine of SpriteKit, I am wondering how I should make the PhysicsBodyComponent, because for this component to work it would need direct access to the physics body of my SpriteKit node, so it would be dependent of the SpriteComponent, but isn't it wrong for components to be dependent on each other ?
How should I do that ?
Thank you.
It depends how you want to structure your components. Like you said its best to keep them as flexible, reusable and independent of each other as much as possible.
So I would just create a simple render component like you want to. This is what I use in my games.
import SpriteKit
import GameplayKit
/// GK sprite component
class SpriteComponent: GKComponent {
// MARK: - Properties
/// The rendered node
let node: SKSpriteNode
// MARK: GKComponent Life Cycle
/// Init with image
init(imageNamed: String) {
node = SKSpriteNode(imageNamed: imageNamed)
}
/// Init with texture
init(texture: SKTexture) {
node = SKSpriteNode(texture: texture)
}
}
In your entity classes you add the component as usual
class Player: GKEntity {
override init() { // pass in an image name if you need to
super.init()
let spriteComponent = SpriteComponent(imageNamed: "Player")
addComponent(spriteComponent)
}
}
Than you add the entity to the scene and position it.
Once a component is added to an entity you can use the component(ofType: ...) method to access its properties, in this case the node property, and do something with them.
class GameScene: SKScene {
// code to add entity to scene
...
// position entity
if let playerNode = player.component(ofType: SpriteComponent.self)?.node {
playerNode.position = CGPoint(...)
}
Go back to your entity class and add the physics body after you added the sprite component.
...
addComponent(spriteComponent)
// Set physics body
if let sprite = component(ofType: SpriteComponent.self)?.node { // component for class is an optional and nil until component is added to entity.
sprite.physicsBody = SKPhysicsBody(...
sprite.physicsBody?.categoryBitMask = ...
...
}
This way all your entities can use 1 render component but have different physics bodies on them and use different positions.
You could create a physics body component and pass into the init method the bit masks etc and the node you want it to be added to. However I think thats makes it quite messy so I prefer this way.
If you do need to make components dependent of each other remember that each GKComponent has an entity property you can use. I would try to avoid this as much as possible to keep your components more flexible.
class SomeComponent: GKComponent {
func test() {
entity?.component(ofType: SomeOtherComponent.self)?.someMethod() // only works if this component is added to entity (entity?) and the other component is also added to entity (...self)?.
}
class SomeOtherComponent: GKComponent {
func someMethod() {
}
}
If you need more info you should read these articles, they are very good.
https://www.raywenderlich.com/119959/gameplaykit-tutorial-entity-component-system-agents-goals-behaviors
http://code.tutsplus.com/tutorials/an-introduction-to-gameplaykit-part-1--cms-24483
Hope this helps
I'm learn as3, and building some exercises from the adobe online tutorials. I'm trying to do a very simple task and I think my code is exactly the same as the tutoriala nd it's not working! I just can't work it out...
I'm trying to change the textfield in a button from that buttons class.
The button is called GameButton, the textfield is called blabel and is classic text and dynamic text. Here is the code for the GameButton class. Instead of displaying "Click" as below it just changes the label to the number 1. The trace statement is working etc it is going there, but the text isn't passing through or something. Please help!!!
package {
import flash.display.MovieClip;
public class GameButton extends MovieClip {
public function GameButton() {
trace("Gamebutton has been created");
this.blabel.text = "Click";
stop();
}
}
}
The long and short of it is you can create the button in code, or else you can try listening for added to stage events coming from the parent object you're adding the children to (maybe the stage, maybe another DisplayObjectContainer). The problem with the listening method is I'm not sure how you would know which child just dispatched the event without making some messy code. I think the first option is generally easier and makes more sense, the only caveat is that you have to place the instances using x/y coordinates or apply scaleX, scaleY to stretch or shrink objects instead of doing it using the authoring tool. You can still use the drag and drop parts of flash to figure out coordinates and build individual movie clips etc.
Enough talk on to some code:
package
{
import flash.display.MovieClip;
public class GameButton extends MovieClip {
private var blabel:TextField; //This can be any display object class or a class that extends from a display object class (Sprite, MovieClip, MyCustomButton etc.)
public function GameButton() {
blabel = new TextField(); //The type after new, should be the same, or a sub-class (extension) of the type used in the variable declaration above
addChild(blabel);
//blabel.x=10; //optional over ten pixels from left
//blabel.y=10; //optional down ten pixels from top
//blabel.scaleX=.5; //optional half the width
//blabel.scaleY=2; //optional 2 times taller
trace("Gamebutton has been created");
blabel.text = "Click";
stop();
}
}
}