Moveable Points - Update variable without Re-referencing variable? Event Subscriptions? (C#, Unity)

Question

So I have this helper script that I use to move points around manually while debugging:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
public class MovablePoints : MonoBehaviour
{
public List<Vector2> points = new List<Vector2>();
public List<int> moveablePoints = new List<int>();
[Range(.01f, 1f)] public float selectionRadius = .05f;
public bool selectionActive;
public Vector2 clickedPos;
public List<Vector2> offsets = new List<Vector2>();
private void Update()
{
 Vector2 mosPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
 if (Input.GetMouseButtonDown(0))
 {
 clickedPos = mosPos;
 for (int i = 0; i < points.Count; i++)
 {
 Vector2 point = points[i];
 if (IsPointInRange(point, mosPos))
 {
 if (!moveablePoints.Contains(i))
 {
 offsets.Add(point - clickedPos);
 moveablePoints.Add(i);
 }
 }
 }
 }
 if (Input.GetMouseButton(0))
 {
 for (int i = 0; i < moveablePoints.Count; i++)
 {
 Vector2 offset = offsets[i];
 points[moveablePoints[i]] = mosPos + offset;
 }
 }
 if (Input.GetMouseButtonUp(0))
 {
 offsets.Clear();
 moveablePoints.Clear();
 }
}
[Range(.001f, .1f)] public float gizmoSize = .05f;
void OnDrawGizmos()
{
 if (selectionActive)
 {
 Color selectionColor = Color.white;
 selectionColor.a = 0.65f;
 Handles.color = selectionColor;
 if (Input.GetAxis("Mouse ScrollWheel") > 0f && selectionRadius < 1)
 selectionRadius += .01f;
 if (Input.GetAxis("Mouse ScrollWheel") < 0f && selectionRadius > 0)
 selectionRadius -= .01f;
 Vector2 mosPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
 Handles.DrawWireDisc(mosPos, new Vector3(0, 0, 1), selectionRadius);
 for (int i = 0; i < points.Count; i++)
 {
 Vector2 point = points[i];
 if (IsPointInRange(point, mosPos))
 {
 if (Input.GetMouseButton(0) && moveablePoints.Contains(i))
 Gizmos.color = Color.green;
 else
 Gizmos.color = Color.red;
 }
 else
 Gizmos.color = Color.white;
 Gizmos.DrawSphere(point, gizmoSize);
 }
 }
}
bool IsPointInRange(Vector2 point, Vector2 mosPos)
{
 float dx = Mathf.Abs(point.x - mosPos.x);
 float dy = Mathf.Abs(point.y - mosPos.y);
 if (dx > selectionRadius)
 return false;
 if (dy > selectionRadius)
 return false;
 if (dx + dy <= selectionRadius)
 return true;
 if (Mathf.Pow(dx, 2) + Mathf.Pow(dy, 2) <= Mathf.Pow(selectionRadius, 2))
 return true;
 return false;
}
}

This an example of how I use and subscribe points to the "Moveable Points"

public Vector2 A = new Vector2();
public Vector2 B = new Vector2();
public Vector2 C = new Vector2();
private void Start()
{
 movablePoints.points.Add(A);
 movablePoints.points.Add(B);
 movablePoints.points.Add(C);
}
void Update()
{
 A = movablePoints.points[0];
 B = movablePoints.points[1];
 C = movablePoints.points[2];
}

However, if multiple scripts are adding points to the MoveablePoints Script, it gets quite hard to remember what index is where. Is there a way to have the MoveablePoints script update the values of the subscriber automatically? Perhaps through reference?

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Answer 1

I don't have experience with unity but what is the problem if you make a class represent a point to collect information about each point (position, offset, color,... etc.)

public class Point
{
 public Vector2 Position { get; set; } = new(0, 0);
 public Vector2 Offset { get; set; } = new(0, 0);
 public Color Color { get; set; } = Color.white;
 public bool IsMoving { get; set; } = false;
}

now you can git ride of this three lists

public List<Vector2> points = new List<Vector2>();
public List<int> moveablePoints = new List<int>();
public List<Vector2> offsets = new List<Vector2>();

and only have single list that hold information you need

public List<Point> points = new();

simplify code

Due to Point class now you can get more readable update method

private void Update()
{
 Vector2 mosPos = Camera.main.ScreenToWorldPoint(Input.mousePosition);
 if (Input.GetMouseButtonDown(0))
 {
 foreach(var point in points) 
 { 
 if (IsPointInRange(point.Position, mosPos))
 {
 point.IsMoving = true;
 point.Offset = point.Position - mosPos;
 }
 }
 }
 if (Input.GetMouseButton(0))
 {
 foreach(var point in points)
 {
 if (point.IsMoving)
 point.Position += mosPos + point.Offset;
 }
 }
 if (Input.GetMouseButtonUp(0))
 {
 foreach (var point in points)
 {
 point.IsMoving = false;
 }
 }
}

for the following code

void OnDrawGizmos()
{
 if (selectionActive)
 {
 //.. all the code 
 }
}

it would be cleaner if you use Inverted "if" statement to reduce nesting (one less indentation)

void OnDrawGizmos()
{
 if (!selectionActive) return;
 //.. all the code 
}

for the following pice of code

for (int i = 0; i < points.Count; i++)
{
 Vector2 point = points[i];
 if (IsPointInRange(point, mosPos))
 {
 if (Input.GetMouseButton(0) && moveablePoints.Contains(i))
 Gizmos.color = Color.green;
 else
 Gizmos.color = Color.red;
 }
 else
 Gizmos.color = Color.white;
 Gizmos.DrawSphere(point, gizmoSize);
}

you can drop the nesting because they are not good for readability as following

foreach (var point in points)
{
 bool IsUnderSelectedArea = IsPointInRange(point.Position, mosPos);
 if (point.IsMoving)
 Gizmos.color = Color.green;
 else if (IsUnderSelectedArea)
 Gizmos.color = Color.red;
 else
 Gizmos.color = Color.white;
 Gizmos.DrawSphere(point. Position, gizmoSize);
}

final advice

you shoud move IsPointInRange to Be in the Point class

public class Point
{
 public Vector2 Position { get; set; } = new(0, 0);
 public Vector2 Offset { get; set; } = new(0, 0);
 public Color Color { get; set; } = Color.white;
 public bool IsMoving { get; set; } = false;
 public bool IsInRangeOfmose(Vector2 mosPos, float radiusRange)
 {
 float dx = Mathf.Abs(Position.x - mosPos.x);
 float dy = Mathf.Abs(Position.y - mosPos.y);
 if (dx > radiusRange)
 return false;
 if (dy > radiusRange)
 return false;
 if (dx + dy <= radiusRange)
 return true;
 if (Mathf.Pow(dx, 2) + Mathf.Pow(dy, 2) <= Mathf.Pow(radiusRange, 2))
 return true;
 return false;
 }
}

this will lead to the following syntex

point.IsInRangeOfmose(mosPos, selectionRadius);