title: Limit font glyphs to the glyph a font have
body: <p>I have a UWP app in which I display demo text using different fonts, the problem is, for some fonts, that if the font does not contains certain glyphs it displays those glyphs with a different font.
  Examples: </p>
  
  <ol>
  <li>If I set the text "The quick brown fox..." in a Textblock using
  EmojiOne the Textblock displays the text using Segoe UI as EmojiOne
  does not contains latin characters (just emojis).</li>
  <li>If I set the text to a set of emojis, and the font I'm using does not contain those glyphs, the Textblock uses Segoe UI Emoji to display those glyphs.</li>
  </ol>
  
  <p>This does not happens, for example if I use Segoe MDL2 Assets, in which case the textblock only use the glyphs that font contains.</p>
  
  <p>What I need is to force a Textblock to use only the glyphs contained in the font I set, and no resolve missing glyphs with other fonts.</p>
  
  <p>Thanks in advance.</p>