Precision problem when moving Rect values

Questions & Answers
1

So I’m having a hard time making sure my Rect.x position always ends up at 0. It’s always higher or lower, and if I use Mathf.RoundToInt, I get random values like 1, -2, 0, -3, 2, -1…

Here’s my code below:

public IEnumerator SlideScreen( RectValues mainRect, int speed, int xPos, bool slideLeft ) {
		
		// Mathf.RoundToInt force the posX to end-up with a rounded value (eg; 0 instead of 0.2562)
		// This is important when sliding the screen back to 0, to make sure it always ends-up at 0.
		
		if( !slideLeft )
		{
			// Move Rect right until it reaches its destination
			while( mainRect.posX < xPos )
			{
				mainRect.posX += Mathf.RoundToInt( ( speed * Time.deltaTime * 10 ) );
				yield return null;
			}
		}
		else
		{
			// Move Rect left until it reaches destination
			while( mainRect.posX > -xPos )
			{
				mainRect.posX -= Mathf.RoundToInt( ( speed * Time.deltaTime * 10 ) );
				yield return null;
			}
		}
	}

What I do with this code is move my Rect.x position to 150, then back to 0. As I said, the problem is that I can never guaranty Rect.x position to be 0 everytime, it jumps between +1 2 3 and -1 2 3

How can I force it to be 0 everytime?
Thanks for your time!

2

Just force Rect.x to the desired position right after the final loop, like this:

    // Move Rect left until it reaches destination
    while( mainRect.posX > -xPos )
    {
        mainRect.posX -= Mathf.RoundToInt( ( speed * Time.deltaTime * 10 ) );
        yield return null;
    }
    mainRect.posX = -xPos; // <--add this line
}

}

3

I’d probably just do:

while( mainRect.posX > -xPos )
{
  yield return null;
  mainRect.posX -= ( speed * Time.deltaTime * 10 );
}
mainRect.posX = -xPos;

That way you’ll check it immediately after changing it, and if it is bad you’ll clamp it before yielding and using the bad value elsewhere.