Unity Selection Box

public class SelectionBoxTest : MonoBehaviour
{
    public Transform startTransform;
    public Transform endTransform;

    public RectTransform selectionBox;

    // Update is called once per frame
    void Update()
    {
        Vector3 startPos = Camera.main.WorldToScreenPoint(startTransform.position);

        Vector3 curPos = Camera.main.WorldToScreenPoint(endTransform.position);

        float width = curPos.x - startPos.x;
        float height = curPos.y - startPos.y;

        Vector3 minScreenPos = new Vector3(Mathf.Min(curPos.x, startPos.x), Mathf.Min(curPos.y, startPos.y));
        Vector3 maxScreenPos = new Vector3(Mathf.Max(curPos.x, startPos.x), Mathf.Max(curPos.y, startPos.y));

        selectionBox.pivot = Vector2.zero;
        selectionBox.anchoredPosition = minScreenPos;
        selectionBox.sizeDelta = new Vector2(Mathf.Abs(width), Mathf.Abs(height));
    }
}