automatically build dependencies

scripts/formulas/msdf-atlas-gen.sh

@@ -74,6 +74,51 @@ VER=1.2.2
 GIT_URL=https://github.com/Chlumsky/msdf-atlas-gen.git
 GIT_TAG="v${VER}"
 
+# bash utilities
+YES=0
+NO=1
+PROBABLY_YES=$YES
+PROBABLY_NOT=$NO
+REMEMBORY_AUTOPILOT=$NO
+THIRDPARTY_BUILD_DIRECTORY="thirdparty"
+
+decision() {
+    # get default
+    if [ "$2" = "$YES" ]; then
+        default="yes"
+    else
+        default="no"
+    fi
+
+    # should we go autopilot
+    if [ "${REMEMBORY_AUTOPILOT}" = "$YES" ];
+    then
+        echo "$1? -> $default"
+        return $2
+    fi
+
+    echo ""
+    echo "$0 NEEDS A DECISION"
+    echo ""
+    echo "> $1?"
+    read -r -p "> Do you want? [y]es / [n]o / [d]efault ($default): " input
+
+    case $input in
+        [yY][eE][sS]|[yY])
+            return $YES
+            ;;
+        [nN][oO]|[nN])
+            return $NO
+            ;;
+        [dD])
+            return "$2" = "$YES"
+            ;;
+        *)
+            return $NO
+            ;;
+    esac
+}
+
 # download the source code and unpack it into LIB_NAME
 function download() {
     echo "download msdf-atlas-gen"
@@ -86,6 +131,63 @@ function download() {
 # prepare the build environment, executed inside the lib src dir
 function prepare() {
     mkdir -p lib/$TYPE
+
+    PREV_DIR="$(pwd)"
+
+    if [ "$TYPE" == "emscripten" ] ; then
+        echo "preparing $TYPE thirdparty dependencies"
+        if decision "download, build and install all thirdparty dependencies" $PROBABLY_YES; then
+            REMEMBORY_AUTOPILOT=$YES
+        fi
+        if decision "download and build tinyxml2 for $TYPE" $PROBABLY_YES; then
+            mkdir -p "thirdparty"
+            cd "thirdparty"
+            if [ -d "tinyxml2" ] ; then
+                echo "apparently already done"
+            else
+                git clone --depth=1 https://github.com/leethomason/tinyxml2.git
+                cd tinyxml2
+                mkdir build && cd build
+                emcmake cmake ..
+                emmake make
+                emmake make install
+            fi
+            cd "$PREV_DIR"
+        fi
+        if decision "download and build zlib for $TYPE" $PROBABLY_YES; then
+            mkdir -p "thirdparty"
+            cd "thirdparty"
+            if [ -d "zlib" ] ; then
+                echo "apparently already done"
+            else
+                wget https://pointer.click/files/zlib-1.3.1.tar.gz
+                mkdir -p zlib
+                tar -xzf zlib-1.3.1.tar.gz -C zlib --strip-components=1
+                cd zlib
+                mkdir build && cd build
+                emcmake cmake ..
+                emmake make
+                emmake make install
+            fi
+            cd "$PREV_DIR"
+        fi
+        if decision "download and build libpng for $TYPE" $PROBABLY_YES; then
+            mkdir -p "thirdparty"
+            cd "thirdparty"
+            if [ -d "libpng-1.6.39" ] ; then
+                echo "apparently already done"
+            else
+                wget https://sourceforge.net/projects/libpng/files/libpng16/1.6.39/libpng-1.6.39.tar.xz/download -O libpng-1.6.39.tar.xz
+                tar -xf libpng-1.6.39.tar.xz
+                cd libpng-1.6.39
+                mkdir build && cd build
+                emcmake cmake ..
+                emmake make
+                emmake make install
+            fi
+            cd "$PREV_DIR"
+        fi
+    fi
 }
 
 # executed inside the lib src dir