title: What are the default typography settings used by IDWriteTextLayout?
body: <p>I would like to disable ligatures, which appear to be enabled by default, at least in the fonts that I'm using (i.e. Calibri).  It appears that the way to do this is to use <code>IDWriteTextLayout::SetTypography</code> to set an <code>IDWriteTypography</code> object to the layout which contains the various ligature-related font features with a value of zero to disable them.  That works to disable the ligatures, but it also affects (disables) other typography settings that I don't want to mess with, such as kerning.</p>
  
  <p>After some experimentation, it turns out that I could disable ligatures just by setting an empty <code>IDWriteTypography</code> object (one that was simply created by the <code>IDWriteFactory</code> and then applied to the layout without alteration).  An empty typography seems to have the effect of setting all possible font features to zero/disable.  So what I actually want to do is retrieve the default typography settings, override the ones related to ligatures, and then set that to the layout.</p>
  
  <p>Unfortunately I can't find anywhere to retrieve the default settings.  Using <code>IDWriteTextLayout::GetTypography</code> just returns null if none has been set, yet it clearly has various typography settings like ligatures enabled in that case.  I also can't find any other methods on <code>IDWriteFactory</code> (or any of its newer versions) or any of the font-related interfaces for creating an <code>IDWriteTypography</code> instance.  How does the <code>IDWriteTextLayout</code> decide which typography settings to use when no <code>IDWriteTypography</code> has been set?  Are the default settings font-specific?  Can I retrieve those settings somehow so that I can tweak a few of them and inherit the default values for the rest?</p>