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Graphics » History » Revision 15

Revision 14 (doak complex, 01/23/2020 08:10 PM) → Revision 15/45 (doak complex, 01/23/2020 08:31 PM)

h1. Graphics 

 By default, _Replicant_ devices use the _Android software renderer_, which relies on the CPU for graphics rendering. Using the dedicated graphics processor (GPU) currently requires non-free software on all of the supported devices. As free-software replacements are not yet available, the GPU cannot be used with _Replicant_ for the moment (see [[GraphicsResearch]]). The software rendering is the reason why _Replicant_ devices appear slow at times and 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 

 TODO: The following enables it globally. Add information about scripts to switch only "non-system"-components (_SurfaceFlinger_, _bootanimation_, _system server_ ?) to _llvmpipe_. 
 TODO: Also add information which files are used for this (@/etc/libGLES_android@ and other files within @/data/data/<app>@). Refer to "this mail":https://lists.osuosl.org/pipermail/replicant/2019-August/002054.html. 

 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 renderer_, 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_. 
 In case the screen compositor (_SurfaceFlinger_) is used with _llvmpipe_, this could have an effect to other apps. For instance with _Gallery_ and _Orbot_ it happens, that some GUI elements are visible, while the main screen is black. The GUI of _Simple File Manager_ works as long as no image is viewed in fullscreen.  

 h2. Known issues with the _Android software renderer_ 

 * Selecting the third option besides photo and video (_Panorama mode_) will crash the _Camera_ app. 
 * 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, happens with _llvmpipe_ as well) 
 * 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 and _Orfox_ 
 * "_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) 

 h2. See also 

 * There is a page about [[GraphicsResearch]] that gather information to improve graphics support.