docs: Update ambient mode to mention disabling bitmap filtering

bug: 19429396
Change-Id: I51c1c58211cbdcb8c293b693627c659fd55537cf

docs/html/training/wearables/watch-faces/drawing.jd

@@ -377,7 +377,8 @@ public void onPropertiesChanged(Bundle properties) {
 
 <ul>
 <li>For devices that use low-bit ambient mode, the screen supports fewer bits for each color
-in ambient mode, so you should disable anti-aliasing.</li>
+in ambient mode, so you should disable anti-aliasing and bitmap filtering when the device switches
+to ambient mode.</li>
 <li>For devices that require burn-in protection, avoid using large blocks of white pixels in
 ambient mode and do not place content within 10 pixels of the edge of the screen, since the
 system shifts the content periodically to avoid pixel burn-in.</li>
@@ -385,7 +386,9 @@ system shifts the content periodically to avoid pixel burn-in.</li>
 
 <p>For more information about low-bit ambient mode and burn-in protection, see
 <a href="{@docRoot}design/wear/watchfaces.html#SpecialScreens">Optimize for Special
-Screens</a>.</p>
+Screens</a>. For more information on how to disable bitmap filtering, see
+<a href="{@docRoot}training/wearables/watch-faces/performance.html#BitmapFiltering">Bitmap
+Filtering</a>.</p>
 
 
 <h2 id="Modes">Respond to Changes Between Modes</h2>

docs/html/training/wearables/watch-faces/performance.jd

@@ -99,7 +99,9 @@ enabled (right).</p>
 setFilterBitmap()} method. <a href="#fig2">Figure 2</a> shows a magnified view of a clock hand with
 and without bitmap filtering.</p>
 
-
+<p class="note"><strong>Note:</strong> In low-bit ambient mode, the system does not reliably
+render the colors in the image for bitmap filtering to process successfully. When ambient mode is
+active, disable bitmap filtering.</p>
 
 <h2 id="OutDrawing">Move Expensive Operations Outside the Drawing Method</h2>