In plain HTML I can do this:
<P>
<IMG SRC="..." WIDTH="50vw" ALIGN="LEFT">text, text...
</P>
to have the image scaled to 50% of the page width and the text flowing along the right-hand side of the image for the height of the image, and then flowing along the full width of the page.
In some readers, I can use WIDTH="50%" to achieve the same, but other readers interpret the 50% as "half the width of the image's full size" and not "half the width of the view (page)".
Is there a consistent way in ePub to tell that I want the image to occupy 50% (or 40%/33% etc.) of the page width and the text to flow around it?