Setting Angled Rectangle Position

Question

I have a rectangle defined by four (x, y) points. It is angled and not aligned with the (x, y) axes.

For example, say I have this rectangle:

lowerLeft   {x=178.77817 y=213.27817 }
lowerRight  {x=207.06244 y=184.99390 }
upperLeft   {x=171.00000 y=205.50000 }
upperRight  {x=199.28426 y=177.21573 }

I want to set its center point to another position, say (419.0, 671.0). How can I determine the new (x, y) points for this rectangle based on its new center position?

I know that I can make an axis aligned rectangle with the same center point and rotate it, but how can I determine the number of degrees to rotate?

Answer 1

Determine the original center point (intersection of diagonals). Use that to determine the translation needed to move it to the new position. Then apply the translation to your 4 other points.