Replicant

h1. Graphics

By default, Replicant devices use the Android software renderer which uses the CPU for graphics rendering. The dedicated graphics processor (GPU) cannot be used with Replicant because for none of the currently supported devices, a fully free software implementation does exist that can make use of it (see [[GraphicsResearch]]). The software rendering is the reason why Replicant devices appear slow at times and it is responsible for a lot of crashes that can happen during usage.

llvmpipe has more complete EGL support than the Android software renderer (see #705), so more apps work with it, like Firefox-based browsers or more recent webviews (see #1780). Unfortunately, llvmpipe is still too slow to be the default renderer, but it is possible to switch back and forth between llvmpipe and the Android software renderer.

h2. Enabling llvmpipe as software renderer

Make sure [[ADB]] is running as root and the system partition [[ADB#Modifying-the-system-partition|is mounted writable]].

The following command switches the software renderer implementation:

<pre>

adb shell "grep -q "ro.libagl=1" /system/build.prop && sed "s/ro.libagl=1/ro.libagl=0/" -i /system/build.prop || sed "s/ro.libagl=0/ro.libagl=1/" -i /system/build.prop" 

</pre>

Then reboot the device. llvmpipe should now be enabled. To switch back to the default Android software rederer, run the above command again and reboot the device.

There are also issues with certain apps when using llvmpipe, although crashes should be less frequent. Usually, the screen stays black if an app does not work with llvmpipe. The gallery app is one of the apps where this happens.

h2. Known issues with the Android software renderer

* Selecting the third option besides photo and video will crash the camera app. This is the panorama mode.

* Video playback in the browser does not work (issue #1533)

* Screenshots do not work (see [[Screenshots]] for a workaround)

* Selecting wallpapers from storage does not work

* Screen content is sometimes shortly visible before unlocking (issue #1275)

* Previews of the windows in the tasks switcher are missing

* Switching between apps, apps and the launcher or different views inside an app is sometimes slow and the device may seem unresponsive

* There are issues with using folders with the Trebuchet launcher (issue #1790, happens with llvmpipe as well)

h3. Popular apps from F-Droid that do not work

* all Firefox-based browsers like "IceCatMobile":https://f-droid.org/repository/browse/?fdfilter=icecat&fdid=org.gnu.icecat

* "Document Viewer":https://f-droid.org/repository/browse/?fdfilter=document+viewer&fdid=org.sufficientlysecure.viewer

* "LibreOffice Viewer":https://f-droid.org/repository/browse/?fdfilter=libreoffice&fdid=org.documentfoundation.libreoffice

* "RedReader":https://f-droid.org/repository/browse/?fdfilter=redreader&fdid=org.quantumbadger.redreader cannot display images ("upstream bug":https://github.com/QuantumBadger/RedReader/issues/279)