This directory contains Android-side modules related to hardware OpenGL ES emulation. The host-side modules and documentation are in $ANDROID_BUILD_TOP/sdk/emulator/opengl.
Note that this directory contains encoder sources that are auto-generated with the 'emugen' host tool (see sdk/emulator/opengl/host/tools/emugen).
To regenerate them, run external/qemu/distrib/update-emugl-sources.sh, after building the emulator from sources, this will populate the content here with the appropriate updated source files.
You should do this whenever you update one of the *.types, *.in and *.attrib files located under one of:
$AOSP/sdk/emulator/opengl/libs/GLESv1_dec/ $AOSP/sdk/emulator/opengl/libs/GLESv2_dec/ $AOSP/sdk/emulator/opengl/libs/renderControl_dec/
or when the 'emugen' tool itself is modified.