Why isn't my vector drawable scaling as expected?
<p>I am attempting to use vector drawables in my Android app.  From <a href="http://developer.android.com/training/material/drawables.html" rel="noreferrer">http://developer.android.com/training/material/drawables.html</a> (emphasis mine):</p>

<blockquote>
  <p>In Android 5.0 (API Level 21) and above, you can define vector drawables, <strong>which scale without losing definition.</strong></p>
</blockquote>

<p>Using this drawable:</p>

<pre><code>&lt;vector xmlns:android="http://schemas.android.com/apk/res/android"
android:height="24dp"
android:width="24dp"
android:viewportWidth="24"
android:viewportHeight="24"&gt;
&lt;path android:fillColor="@color/colorPrimary" android:pathData="M14,20A2,2 0 0,1 12,22A2,2 0 0,1 10,20H14M12,2A1,1 0 0,1 13,3V4.08C15.84,4.56 18,7.03 18,10V16L21,19H3L6,16V10C6,7.03 8.16,4.56 11,4.08V3A1,1 0 0,1 12,2Z" /&gt;
</code></pre>

<p></p>

<p>and this ImageView:</p>

<pre><code>&lt;ImageView
    android:layout_width="400dp"
    android:layout_height="400dp"
    android:src="@drawable/icon_bell"/&gt;
</code></pre>

<p>produces this blurry image when attempting to display the icon at 400dp (on a largish high-res circa 2015 mobile device running lollipop):</p>

<p><a href="https://i.stack.imgur.com/ELOQi.png" rel="noreferrer"><img src="https://i.stack.imgur.com/ELOQi.png" alt="blurryBellIcon"></a></p>

<p>Changing the width and height in the definition of the vector drawable to 200dp significantly improves the situation at the 400dp rendered size.  However, setting this as a drawable for a TextView element (i.e. icon to the left of the text) now creates a huge icon.</p>

<p>My questions:</p>

<p>1) Why is there a width/height specification in the vector drawable?  I thought the entire point of these is that they scale up and down losslessly making width and height meaningless in its definition?</p>

<p>2) Is it possible to use a single vector drawable which works as a 24dp drawable on a TextView but scales up well to use as much larger images too?  E.g. how do I avoid creating multiple vector drawables of different sizes and instead use one which scales to my rendered requirements?</p>

<p>3) How do I effectively use the width/height attributes and what is the difference with viewportWidth/Height?</p>

<p>Additional details:</p>

<ul>
<li>Device is running API 22</li>
<li>Using Android Studio v1.5.1 with Gradle version 1.5.0</li>
<li>Manifest is compile and target level 23, min level 15.  I've also tried moving min level to 21, but this made no difference.</li>
<li>Decompiling the APK (with min level set to 21) shows a single XML resource in the drawable folder.  No rasterized images are produced.</li>
</ul>