Rotating a Sprite around a point by User Input

I need help in Rotating a Sprite by some delta Angle around a pivot point when user interacts with the game.

I am able to rotate the sprite, but not able to rotate it according to how much the touch screen position changed.

Basically the speed of rotation and speed of touch position change is different, but ideally they should be the same.

Any ideas anyone?

I am using a perspective camera, and am also utilizing a mathematical formula to find delta Angle with which to Rotate by.
This formula is basically,

DeltaAngle = Distance/Radius

where Distance is the length of arc along which the sprite moves,
Radius is the distance between sprite and Rotating pivot.

Currently my Distance and Radius are in world units

Touch.deltaPosition gives you the difference of touch position between every frame.

I do not know, how your code looks like. Can you raycast the sprite?
Take a look at rotating-an-object-with-touch

I am getting the touched world position… only thing is that i want the sprite to rotate at the same speed i move my fingers, irrespective of how far the object is from the perspective camera.

So, these are the variables i already have with me:

  1. Touch Screen Delta
  2. Touch World Delta
  3. Radius of Rotation
  4. Rotation Pivot

I need to find the Angle by which to rotate, so it appears that the rotation is happening in sync with my moving finger.