How to tell if mouse is moving clockwise or counterclockwise

Questions & Answers
1

I need to know what math I need to check if the mouse is moving clockwise or counterclockwise. I am not sure where to start with this…

EDIT: A little more detail, though, I have figured out this tends to scare away answers, so I try to avoid having a big block of info…

This all may be a very bad way of doing this, so if you know a better way, don’t be afraid to change it all.

What I am trying to do is create a rotation manipulator much like Maya’s. The camera can view it from any angle, so it is quite confusing. But here is what I have done so far

//"this" is the rotation maninpulator
Vector3 manipPos = ManipulatorCamera.WorldToScreenPoint(this.transform.position);
float o = Vector3.Distance(Input.mousePosition, mousePositionLastFrame);
float a = Vector3.Distance(mousePositionLastFrame, manipPos);
			
float angle = Mathf.Rad2Deg*Mathf.Atan(o/a)*GetDirection(manipPos,Input.mousePosition,mousePositionLastFrame);
Managers.SelectionManager.SelectedSmartPart.transform.localEulerAngles = new Vector3(
    Managers.SelectionManager.SelectedSmartPart.transform.localEulerAngles.x,
    Managers.SelectionManager.SelectedSmartPart.transform.localEulerAngles.y,
    Managers.SelectionManager.SelectedSmartPart.transform.localEulerAngles.z + angle
);
			
mousePositionLastFrame = Input.mousePosition;

Since direction is always positive, I have to figure out the direction. GetDirection is defined as

private int GetDirection(Vector3 manipPos, Vector3 newMousePos, Vector3 oldMousePos)
	{
		//Where in the coordinate system compared to the manipPos
		//is the mouse
		Vector3 coord = newMousePos - manipPos;
		
		//Gets the direction
		Vector3 dir = newMousePos - oldMousePos;
		
		if(coord.x >= 0 && coord.y >= 0)
		{
			if(dir.x >= 0 && dir.y <= 0)
				return -1;
			else if(dir.x <= 0 && dir.y >= 0)
				return 1;
		}
		else if(coord.x >= 0 && coord.y <= 0)
		{
			if(dir.x <= 0 && dir.y <= 0)
				return -1;
			else if(dir.x >= 0 && dir.y >= 0)
				return 1;
		}
		else if(coord.x <= 0 && coord.y <= 0)
		{
			if(dir.x <= 0 && dir.y >= 0)
				return -1;
			else if(dir.x >= 0 && dir.y <= 0)
				return 1;
		}
		else
		{
			if(dir.x >= 0 && dir.y >= 0)
				return -1;
			else if(dir.x <= 0 && dir.y <= 0)
				return 1;
		}
		
		return 0;
	}

But this gets really messed up at each 90 degree angle because this assumes you are moving in a perfect circle. There has to be a better way. Any ideas?

2

I’m not familiar with Maya’s thing, but offhand I would say it would be something like:

Get screen coord of object (world to screen)

Initially, get ray from object to mouse (2D, just subtract object origin from current mouse).

On update, keep doing that, but compare current ray to initial ray (or last ray), and you can get the angle using trig function like atan2 or something along those lines.

Not a solid answer admittedly but maybe something there will help.