Building WebAssembly samples using Docker
=========================================

The script "./docker-build.sh" can be used to quickly build the
WebAssembly samples on any GNU/Linux distribution equipped with
Docker. This avoids newcomers to install Emscripten and learn the
CMake options. Just type:

$ ./docker-build.sh Release

After successful build, the binaries will be installed in the
following folder (i.e. in the folder "wasm-binaries" at the root of
the source distribution):

$ ls -l ../../wasm-binaries


NB: The source code of the Docker build environment can be found at
the following location:
https://github.com/jodogne/OrthancDocker/tree/master/wasm-builder


Building WebAssembly using Docker & interactively
=================================================


ROOT_DIR=$(pwd)/../../..
mkdir -p ${ROOT_DIR}/wasm-binaries
docker run -it --rm \
    --dns=8.8.8.8 \
    --user $(id -u):$(id -g) \
    -v ${ROOT_DIR}:/source \
    -v ${ROOT_DIR}/wasm-binaries:/target jodogne/wasm-builder:3.1.49 \
    bash

# In Docker:
mkdir /tmp/build
cd /tmp/build
source /opt/emsdk/emsdk_env.sh

cmake /source/Applications/StoneWebViewer/WebAssembly \
      -DCMAKE_BUILD_TYPE=Debug \
      -DORTHANC_STONE_INSTALL_PREFIX=/target/StoneWebViewer \
      -DCMAKE_TOOLCHAIN_FILE=${EMSDK}/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake \
      -DSTATIC_BUILD=ON \
      -DLIBCLANG=/usr/lib/llvm-4.0/lib/libclang-4.0.so \
      -G Ninja

ninja -j12 install

# each time you modify code, run the ninja command again

# to serve the WASM code, you may use
    "ServeFolders": {
        "/stone-webviewer-live" : "/home/alain/o/orthanc-stone/wasm-binaries/StoneWebViewer/"
    }


Native compilation (without Docker)
===================================

Install Emscripten:
https://emscripten.org/docs/getting_started/downloads.html

Then, if the installation path is "~/Downloads/emsdk/":

# source ~/Downloads/emsdk/emsdk_env.sh
# mkdir Build && cd Build
# cmake .. -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_TOOLCHAIN_FILE=${EMSDK}/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake \
  -DALLOW_DOWNLOADS=ON -G Ninja
# ninja install

=> The binaries will be put in "../../../wasm-binaries/StoneWebViewer/"


Debian unstable
===============

Last update: 2020-11-18

IMPORTANT - Currently broken: The linker fails on Debian Sid with the
default package. A workaround is available using "experimental"
packages:
https://github.com/emscripten-core/emscripten/issues/11895#issuecomment-729840497
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=975069


# sudo apt-get install emscripten python3-clang python3-pystache ninja-build
# mkdir Build && cd Build
# EMSCRIPTEN=/usr/bin/ cmake .. -DCMAKE_BUILD_TYPE=Release \
  -DCMAKE_TOOLCHAIN_FILE=/usr/share/emscripten/cmake/Modules/Platform/Emscripten.cmake \
  -DLIBCLANG=/usr/lib/x86_64-linux-gnu/libclang-9.so \
  -DALLOW_DOWNLOADS=ON -G Ninja
# ninja install

=> The binaries will be put in "../../../wasm-binaries/StoneWebViewer/"

The invokation of CMake will give the following warning, that can be safely ignored:

"System is unknown to cmake, create:
Platform/Emscripten to use this system, please post your config file on discourse.cmake.org so it can be added to cmake"