how to limit and clamp distance between two points in a Line renderer unity2d - unity3d

Question

I am making a game which let you click on a ball and drag to draw a line renderer with two points and point it to a specific direction and when release I add force to the ball,
for now, I just want to know how can I limit the distance between those two points like give it a radius.

Answer 1

You can simply clamp it using a Mathf.Min.
Since you didn't provide any example code unfortunately here is some example code I made up with a simple plane with a MeshCollider, a child object with the LineRenderer and a camera set to Orthographic. You probably would have to adopt it somehow.
public class Example : MonoBehaviour
{
// adjust in the inspector
public float maxRadius = 2;
private Vector3 startPosition;
[SerializeField] private LineRenderer line;
[SerializeField] private Collider collider;
[SerializeField] private Camera camera;
private void Awake()
{
line.positionCount = 0;
line = GetComponentInChildren<LineRenderer>();
collider = GetComponent<Collider>();
camera = Camera.main;
}
// wherever you dragging starts
private void OnMouseDown()
{
line.positionCount = 2;
startPosition = collider.ClosestPoint(camera.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, transform.position.z)));
var positions = new[] { startPosition, startPosition };
line.SetPositions(positions);
}
// while dragging
private void OnMouseDrag()
{
var currentPosition = GetComponent<Collider>().ClosestPoint(camera.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, transform.position.z)));
// get vector between positions
var difference = currentPosition - startPosition;
// normalize to only get a direction with magnitude = 1
var direction = difference.normalized;
// here you "clamp" use the smaller of either
// the max radius or the magnitude of the difference vector
var distance = Mathf.Min(maxRadius, difference.magnitude);
// and finally apply the end position
var endPosition = startPosition + direction * distance;
line.SetPosition(1, endPosition);
}
}
This is how it could look like

Answer 2

I've written the following pseudo code, which may help you
float rang ;
Bool drag=true;
GameObject ball;
OnMouseDrag () {
if(drag) {
//Put your dragging code here
}
if (ball.transform.position>range)
Drag=false;
else Drage=true;
}