Rotate object 2d

Hello,
When I try to rotate this wheel if I click on partition 3, partition 1 automatically goes instead of 3 and then rotates as I want. Basically I would like to stay 3 under the cursor.
Partition 3 was like an example. I need that no matter where I click the rotation starts from there.
Any help, please?
Sorry for my bad english.

My code:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class rotate : MonoBehaviour
6. {
7.     private void OnMouseDrag()
8.     {
9.         Vector3 mouse_pos = Input.mousePosition;
10.         Vector3 wheel_pos = Camera.main.WorldToScreenPoint(this.transform.position);
11.  
12.         mouse_pos.x = mouse_pos.x - wheel_pos.x;
13.         mouse_pos.y = mouse_pos.y - wheel_pos.y;
14.  
15.         float angle = Mathf.Atan2 (mouse_pos.y, mouse_pos.x) * Mathf.Rad2Deg;
16.         this.transform.rotation = Quaternion.Euler (new Vector3(0, 0, angle));
17.     }
18. }

Edit:

 

If it's exactly the opposite direction, try just rotating by angle+180° instead of just angle.

 

Hello,
Thanks for the reply.
Partition 3 was like an example. I need that no matter where I click the rotation starts from there.

 

Have you tried solution which I proposed?

 

Yes, I tried but it didn't solve my problem.
In attach is a simulation for the first situation.
If I put "angle + 180 °" instead of partition 1 is partition 3, but it's still not what I need.
Thanks anyway.

 

Ah. I see. You are just setting angle. Try getting angle on mouse click and then put the difference between angles into the rotation function.

Code (CSharp):

1. this.transform.rotation = Quaternion.Euler (new Vector3(0, 0, Mathf.Abs(angle_at_press - angle_at_release)));

 

Hi!
For angle on mouse click:

Code (CSharp):

1. Vector3 angle_at_press = Camera.main.WorldToScreenPoint(Input.mousePosition);

but how can I determine "angle_at_release"?

 

Oh, sorry. For you that is angle during drag. So you can reuse most of the stuff from your first post.

Code (CSharp):

1. private void OnMouseDrag()
2.     {
3.         Vector3 mouse_pos = Input.mousePosition;
4.         Vector3 wheel_pos = Camera.main.WorldToScreenPoint(this.transform.position);
5.         mouse_pos.x = mouse_pos.x - wheel_pos.x;
6.         mouse_pos.y = mouse_pos.y - wheel_pos.y;
7.         float angle = Mathf.Atan2 (mouse_pos.y, mouse_pos.x) * Mathf.Rad2Deg;
8.         this.transform.rotation = Quaternion.Euler (new Vector3(0, 0, Math.abs(angle - (Mathf.Atan2 (angle_at_press.y, angle_at_press.x) * Mathf.Rad2Deg))));
9.     }

 

I have tried now but I get this error:
The name `angle_at_press' does not exist in the current context.

 

You need to declare in context and assign it on mouse press. It won't exist otherwise.

Code (CSharp):

1.  
2. Vector3 angle_at_press;
3.  
4. void Update ()
5.  {
6.  
7.     if (Input.GetMouseButtonDown(0))
8.     {
9.         angle_at_press = Camera.main.WorldToScreenPoint(Input.mousePosition);
10.     }
11. }
12.  
13. private void OnMouseDrag()
14.     {
15.         Vector3 mouse_pos = Input.mousePosition;
16.         Vector3 wheel_pos = Camera.main.WorldToScreenPoint(this.transform.position);
17.         mouse_pos.x = mouse_pos.x - wheel_pos.x;
18.         mouse_pos.y = mouse_pos.y - wheel_pos.y;
19.         float angle = Mathf.Atan2 (mouse_pos.y, mouse_pos.x) * Mathf.Rad2Deg;
20.         this.transform.rotation = Quaternion.Euler (new Vector3(0, 0, Math.abs(angle - (Mathf.Atan2 (angle_at_press.y, angle_at_press.x) * Mathf.Rad2Deg))));
21.     }

 

Thank you very much for the answer.
Neither this script doesn't work as I wanted.
I think I'll give up with that. I'm a beginner and I should probably start with some easier things.
Thanks again for your help and for your time.