Chromium Embedded Framework's cefsimple Off-Screen Rendering
I needed to use a modifed version of cefsimple using either SDL or OpenGL Core. I tried these three GitHub repos:
- SDL: https://github.com/gotnospirit/cef3-sdl2
- OpenGL Core: https://github.com/if1live/cef-gl-example
- OpenGL Core: https://github.com/andmcgregor/cefgui
But they are outdated (more than > 4 years), the CEF API changed and when I compiled they crash by forking indefinitively the application until my Linux fell down. So they are not safe to be used! I tried to update fixes, so here is the repo.
It's working on my Linux 64-bits Debian 11 and CEF 96.0.14 downloaded at https://cef-builds.spotifycdn.com/index.html
Before compiling cefsimple, you need some libs and packages from CEF inside the two folders cefsimple_sdl and cefsimple_opengl.
Setup
Firstly, let name some folders. This will shorter code in this document. Adapt the CEF version to your operating system with the desired version according to https://cef-builds.spotifycdn.com/index.html
TMP=/tmp
CEF_LINK=https://cef-builds.spotifycdn.com/cef_binary_96.0.14%2Bg28ba5c8%2Bchromium-96.0.4664.55_linux64.tar.bz2
CEF=$TMP/cef_binary_96.0.14+g28ba5c8+chromium-96.0.4664.55_linux64
CEF_TARBALL=$CEF.tar.bz2
CEFSIMPLE_SDL=$CEF/tests/cefsimple_sdl
CEFSIMPLE_GL=$CEF/tests/cefsimple_opengl
Download and decompress it inside a temporary folder:
wget $CEF_LINK
tar jxvf $CEF_TARBALL
Git clone this repo inside the cef folder:
cd $CEF
git clone https://github.com/Lecrapouille/OffScreenCEF.git --depth=1
Compile CEF (needs some minutes, not hours):
mkdir $CEF/build
cd $CEF/build
cmake -DCMAKE_BUILD_TYPE=Debug ..
make -j$(nproc)
You can use -DCMAKE_BUILD_TYPE=Release instead but just avoid mixing debug and release symbols. Now we have to copy needed elements for compiling cefsimple_sdl and cefsimple_opengl:
cp -v $CEF/Debug/libcef.so $CEF/build/libcef_dll_wrapper/libcef_dll_wrapper.a $CEFSIMPLE_SDL
(cd $CEF/build/tests/cefsimple/Debug/
cp -v icudtl.dat resources.pak chrome_100_percent.pak chrome_200_percent.pak v8_context_snapshot.bin $CEFSIMPLE_SDL
)
mkdir -p $CEFSIMPLE_SDL/locales
cp -v $CEF/build/tests/cefsimple/Debug/locales/en-US.pak $CEFSIMPLE_SDL/locales
Do the same thing for $CEFSIMPLE_GL.
Compilation
cd $CEFSIMPLE_SDL && ./build.sh
cd $CEFSIMPLE_GL && ./build.sh
You have two binaries:
$CEFSIMPLE_SDL/cefsimple_sdl$CEFSIMPLE_GL/cefsimple_opengl
These applications do not have command lines, you have to edit the code to give your desired page.
Important note
CefExecuteProcess shall be called before OpenGL/SDL2 context and using the command line of your application (int argc, char* argv[]). If not your system can freeze. Here is the function documentation (caf_app.h file):
This function should be called from the application entry point function to
execute a secondary process. It can be used to run secondary processes from
the browser client executable (default behavior) or from a separate
executable specified by the CefSettings.browser_subprocess_path value. If
called for the browser process (identified by no "type" command-line value)
it will return immediately with a value of -1. If called for a recognized
secondary process it will block until the process should exit and then return
the process exit code. The |application| parameter may be empty. The
|windows_sandbox_info| parameter is only used on Windows and may be NULL (see
cef_sandbox_win.h for details).
