Object Interaction

Hello all! Wow… what a few years can do, huh? I have a habit of posting on my birthday, because that’s on of the few days a year you get to do exactly what you want, and writing code is what I want to do! And sharing that code is always fun too! So I thought that in honor of this yearly tradition, we would visit some old code! February of 2018 saw me write some of my first scripts in Unity. I was already pretty well versed in writing code, but Unity was new to me! I ended up writing a few scripts, but one of the scripts I was most proud of was my Object Interaction script. Simple, yeah I know, but I was very proud of this!

Well, here we are now as I turn 23, and am much more confident in my programming, my Unity ability, design ability, and as a human being in general! So why not create an object interaction interface that more properly represents me as I am now? Lets start with just that!

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

public interface IInteractable
{
    string IPrompt();

    void IAction();

    bool IsInteractable();
}

So lets say that IPrompt is the string that pops up on your screen when you’re within range of interacting with the game object. IAction is what the object does upon interacting. IIsInteractable will help us turn off items after one use or once they are not to be used any more!

Easy Enough! Bye!

Just kidding…….. So from here we have to build ourselves an Interacter which we will attach to the player, that will allow the player to interact with items that inherit from IInteractable! So here I’ll sort of get our of detail and loosely tell you what’s going on here! I wanted to make the interactions like they are in Dark Souls, where you can cycle through multiple intractable objects if they are present, and choose which one you would like to interact with! So I build this interacter around an ArrayList, which stores the currently “selected” element in an int. From here, I just have an OnTriggerEnter and Exit that will add the IInteractables to the ArrayList, and allow the player to sort through their IPrompts, and interact with their different IActions!

That really is it for this one! Lots of private methods to just manage the backend of scrolling and interacting, but I’ll include it all here… Please excuse my debug notes! This was also built as a part of the Project Rat I mentioned in my previous post.. I hope you guys like this code and can see the difference in my skill from 2 years ago to now…. Well I should hope you see the difference…. Here’s some code:

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

public class Interacter : MonoBehaviour
{

    //LIFO will keep 
    // private Stack<IInteractable> LIFO = new Stack<IInteractable>();
   
    //AL Instantiation    
    ArrayList InteractionAL = new ArrayList();

    public int selection = 1;



    // Update is called once per frame
    void Update()
    {
        if (Input.GetKeyDown(KeyCode.E))
        {
            doSomething();
        }
        else if (Input.GetKeyDown(KeyCode.R))
        {
            scrollSelection();
        }
    }

    //Adds Object to the ArrayList if is interactible
    private void OnTriggerEnter(Collider other)
    {

        Debug.Log("Something entered my zone!");

        //Gets the game object from the collider entered
        //HERE
        IInteractable newInteractable = other.GetComponent<IInteractable>();

        //If is interatable, add
        if (newInteractable.IsInteractable())
        {
            InteractionAL.Add(newInteractable);

            //Debug Log
            Debug.Log("Added");

        }

    }

    //Removes most recent from the ArrayList on exit
    private void OnTriggerExit(Collider other)
    {
        //Debug Log
        Debug.Log("-1 in array");

        //Finds the collider exited, and removes from the AL
        InteractionAL.Remove(other.GetComponent<IInteractable>());

        
    }

    //Returns the prompt of the IInteractible 
    public string getPrompt(IInteractable temp)
    {

        //Debug Log
        Debug.Log(temp.IPrompt());

        //Returns prompt
        return temp.IPrompt();
    }
    

    //Calls IAction
    //Possibly remove if one time use only
    private void doSomething()
    {

        //Temp IInteractabale
        IInteractable temp = getSelected();

        //If not null
        if(temp != null)
        {

            //Do Something
            temp.IAction();
           
            //Debug
            getPrompt(getSelected());

        }

  
    }

    //Retrieves the IInteractable which is currently to be displayed
    //Incremented by scrollSelecion()
    private IInteractable getSelected()
    {
        //If not empty
        if(InteractionAL.Count != 0)
        {
            //castes the IInteractable as an IInteractable
            return (IInteractable)InteractionAL[(selection - 1)];
        }

        //else
        else
        {
            return null;
        }
      
    }

    //Increments the int which getSelected returns
    private void scrollSelection()
    {
        //Takes size of ArrayList starting at 1
        int tempSize = InteractionAL.Count;

        //Increments selection as long as it's not at the end
        if (selection < tempSize)
        {
            selection++;
        }

        //Resets the scroll selection to the front. 
        //I hate hardcoding this, but this wont change as long as we use .Count
        else if(selection == tempSize) 
        {
            selection = 1;
        }

    }
}