Use local emsdk so that emsdk version can be pinned

.gitignore

@@ -12,3 +12,4 @@ sources/webshims
 sources/minetest
 sources/irrlichtmt
 sources/minetest_game
+emsdk/

Dockerfile

@@ -29,6 +29,6 @@ RUN \
 	   cd "$HOME"/emsdk \
 	&& . ./emsdk_env.sh \
 	&& cd /minetest-wasm \
-	&& ./apply_patches.sh \
 	&& ls -la \
+        && ./install_emsdk.sh \
 	&& ./build_all.sh

README.md

@@ -10,14 +10,6 @@ This has only been tested on Ubuntu 20.04.
 
 * Ubuntu: apt-get install -y build-essential cmake tclsh
 
-Pre-requisites
---------------
-The Emscripten SDK (emsdk) must be installed, activated, and in the PATH.
-It is assumed to be installed in $HOME/emsdk (edit `common.sh` to change this).
-The emsdk directory must be patched exactly once by running:
-
-    ./apply_patches.sh
-
 Building
 ---------
 
@@ -31,3 +23,29 @@ If the build completes successfully, the www/ directory will contain the entire
 includes an `.htaccess` file which sets headers that are required (by browsers) to load the app. 
 If your webserver does not recognize `.htaccess` files, you may need to set the headers in
 another way.
+
+Network Play
+------------
+
+By default, the proxy server is set to `wss://minetest.dustlabs.io/proxy` (see static/launcher.js).
+This is necessary for network play, since websites cannot open normal TCP/UDP sockets. This proxy
+is located in California. There are regional proxies which may perform better depending on your
+location:
+
+North America (Dallas) - wss://na1.dustlabs.io/mtproxy
+South America (Sao Paulo) - wss://sa1.dustlabs.io/mtproxy
+Europe (Frankfurt) - wss://eu1.dustlabs.io/mtproxy
+Asia (Singapore) - wss://ap1.dustlabs.io/mtproxy
+Australia (Melbourne) - wss://ap2.dustlabs.io/mtproxy
+
+You could also roll your own own custom proxy server. The client code is here:
+
+https://github.com/paradust7/webshims/blob/main/src/emsocket/proxy.js
+
+Custom Emscripten
+-----------------
+The Emscripten SDK (emsdk) will be downloaded and installed the first time you build. To provide
+your own instead, set $EMSDK before building (e.g. using `emsdk_env.sh`). An external Emscripten
+may need to be patched by running this exactly once:
+
+    ./apply_patches.sh /path/to/emsdk

apply_patches.sh

@@ -1,7 +1,13 @@
 #!/bin/bash -eu
 
-source common.sh
+BASE_DIR="$(dirname -- "$(readlink -f -- "$0")")"
 
+if [ $# -ne 1 ]; then
+    echo "Usage: $0 /path/to/emsdk"
+    exit 1
+fi
+
+EMSDK_ROOT="$1"
 cd "$EMSDK_ROOT"
 
 patch -p1 < "$BASE_DIR/emsdk_emcc.patch"

common.sh

@@ -4,6 +4,28 @@ cd "$BASE_DIR"
 # Debug / Release
 export BUILD_KIND="${BUILD_KIND:-release}"
 
+# Setup emscripten (if not already)
+export EMSDK="${EMSDK:-use_local_install}"
+if [ "$EMSDK" == "use_local_install" ]; then
+    if [ ! -d emsdk ]; then
+        set +x
+        echo "-------------------------------------------------------"
+        echo "Emscripten is not installed. (EMSDK not set)"
+        echo "Press ENTER to install it into emsdk/. Ctrl-C to abort."
+        echo "-------------------------------------------------------"
+        read unused_var
+        if [ "$unused_var" != "" ]; then
+            echo "Aborting"
+            exit 1
+        fi
+        set -x
+        ./install_emsdk.sh
+    fi
+    pushd emsdk
+    source ./emsdk_env.sh
+    popd
+fi
+
 case $BUILD_KIND in
   debug)
     export MINETEST_BUILD_TYPE="Debug"
@@ -40,7 +62,7 @@ export CFLAGS="$COMMON_CFLAGS -pthread -sUSE_PTHREADS=1 -fexceptions"
 export CXXFLAGS="$COMMON_CFLAGS -pthread -sUSE_PTHREADS=1 -fexceptions"
 export LDFLAGS="$COMMON_LDFLAGS -pthread -sUSE_PTHREADS=1 -fexceptions -sEXIT_RUNTIME"
 
-export EMSDK_ROOT="$HOME/emsdk"
+export EMSDK_ROOT="$EMSDK"
 export EMSDK_SYSLIB="${EMSDK_ROOT}/upstream/emscripten/cache/sysroot/lib/wasm32-emscripten"
 export EMSDK_SYSINCLUDE="${EMSDK_ROOT}/upstream/emscripten/cache/sysroot/include"
 

install_emsdk.sh

@@ -0,0 +1,16 @@
+#!/bin/bash -eux
+
+BASE_DIR="$(dirname -- "$(readlink -f -- "$0")")"
+
+cd "$BASE_DIR"
+
+rm -rf emsdk
+git clone https://github.com/emscripten-core/emsdk.git
+
+pushd emsdk
+./emsdk install 3.1.25
+./emsdk activate 3.1.25
+popd
+
+./apply_patches.sh emsdk
+