efficient sequencer

Unity Engine
1

Hi I’m trying to find a better way to sequence functions in script.
essentially I have my mainCharacter going across the screen when he triggers the scene end the scene is de-activated and the next scene becomes active. (also the mainCharacter resets to the beginning) It requires me to have a list of if statements. How would I do this in a better way? Arrays? enums maybe? Or should I use events? Thanks for your input.

if (mainCharacter.transform.position.x > scene.end) {sceneNum = sceneNum +1;}

if (sceneNum == 1) scene.one.SetActive(true); else scene.one.SetActive(false);
if (sceneNum == 2) scene.two.SetActive(true); else scene.two.SetActive(false);
if (sceneNum == 3) scene.three.SetActive(true); else scene.three.SetActive(false);
if (sceneNum == 4) scene.four.SetActive(true); else scene.four.SetActive(false);
if (sceneNum == 5) scene.five.SetActive(true); else scene.five.SetActive(false);

2

Maybe a switch statement is what you’re looking for?

http://unity3d.com/learn/tutorials/modules/beginner/scripting/switch

3

Or just put your scenes into array and use code like this:

for (int i = 0; i < scenes.Length; i++) {
  scenes[i].SetActive(i == sceneNum);
}
2 Likes
4

Ah, I got it to work. Thats the pro solution I was looking for. Thanks mholub!

5

I wonder if there is a way to sequence like this for functions too?

6

What do you mean? To call a function stored inside collection?

using UnityEngine;
using System.Collections.Generic;
using System;

public class SequencedFunctionCaller : MonoBehaviour {
    private List<Action> actions = new List<Action>(); // Action is a callable type without arguments
    // Use this for initialization
    void Start () {
        actions.Add(() => Debug.Log("hello world")); // lambda function
        actions.Add(someFunction);

        actions[1](); // calls someFunction
        call (1); // same
    }

    void someFunction() {
        Debug.Log("some function");
    }

    void call(int i) {
        actions[i]();
    }

    // Update is called once per frame
    void Update () {

    }
}

And please look at UnityEvent:

It can be added as public field into MonoBehaviour and it has nice GUI. You can store UnityEvents into List too. And invoke them with event_.Invoke()_ call;

2 Likes
7

A switch may be the better choice here as I need to add custom functions everytime the scene changes. I want to figure out how events work but I’m using js and the docs and examples are fairly confusing or just broken.
Perhaps next project I’ll switch to C#. I’m still just a 6 months noob at scripting.

8

It’s same in UnityScript.

#pragma strict

import UnityEngine.Events;

var events : UnityEvent[];

// this code will invoke all events on Start which you can specify by Inspector
// just put the component on some gameobject and add some events
function Start () {
	for (var i = 0; i < events.Length; i++) {
		events[i].Invoke();
	}
}
1 Like
9

Oh wow, this is amazing! Thank You. This would have saved me so much trouble if I knew of it months ago.

10

One last thing, Let say the main character.position.x is greater than scene.position.x. When its true i invoke an event. I check for this in an if statement in update. When it becomes true it sends and event just once until it resets. Whats the best way to do this? I keep reading to use co-routine but haven’t found an example of how it would work.

11

I usually use just simple boolean flag for such task.

#pragma strict

import UnityEngine.Events;

var Character : Transform;
var Scene : Transform;

var OnPositionEvent : UnityEvent;

private var eventFired : boolean;

function Start () {
}

function Update () {
	if (!eventFired && Character.position.x > Scene.position.x) {
		OnPositionEvent.Invoke();
		eventFired = true;
	}
}

function Reset() {
	eventFired = false;
}

function OnGUI() {
  if (GUILayout.Button("Reset")) {
  	Reset();
  }
}

I don’t know how to use coroutine for this. If you can point me into some link you read about it I will be thankful.

1 Like
12

I just googled “call function once from update” there are a lot of postings but a boolean flag seems to be the only way. Others keep saying to use co-routine without giving an example. There must be a simpler and more elegant way to do this. I guess this isn’t terrible.

13

I would love to know anymore useful programming tricks mholub. Thanks!