This is a simple experiment and has only been tested with IE 5.01 and Mozilla 0.9.7.
The image is 300x300 pixels and is a 2 pixel-wide diagonal line. The IMG is contained by an absolutely positioned DIV. The image is animated by moving the DIV and resizing the IMG - the effect is that the center of the line doesn't move, and it appears that the line itself is changing length and orientation.
This experiment is not a final solution - but is for generating ideas about how to make use of this. For example, a useful function might be one that let's you specify only the change in length or orientation of the line. Then we would have a Vector object.
As you can see we need some scaling so the width and height change at the same rate.
I welcome your ideas. Please contribute to this thread at HelpFromTechs.com.