stract&nbsp;float&nbsp;getScaleFactor(int&nbsp;sourceWidth,
                                     int&nbsp;sourceHeight,
                                     int&nbsp;requestedWidth,
                                     int&nbsp;requestedHeight)</pre>
<div class="block">Returns a float (0, +infinity) indicating a scale factor to apply to the source
 width and height when displayed in the requested width and height.

 <p>The returned scale factor will be split into a power of two sample size applied via
 <a h