Add WebAssembly / Emscripten as new compilation target

.gitignore

@@ -1,4 +1,6 @@
 .p4*
 .DS_Store
 .AppleDouble
+USD_emscripten/
+.vscode/
 

CMakeLists.txt

@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.12)
 
 project(usd)
 
-if (NOT CMAKE_SIZEOF_VOID_P EQUAL 8)
+if (NOT CMAKE_SIZEOF_VOID_P EQUAL 8 AND NOT PXR_ENABLE_JS_SUPPORT)
     if (WIN32)
         message(FATAL_ERROR "Compiler does not support 64-bit builds. "
                 "If you are using Visual Studio, make sure you are in the "
@@ -37,6 +37,15 @@ include(CXXDefaults)
 add_definitions(${_PXR_CXX_DEFINITIONS})
 set(CMAKE_CXX_FLAGS "${_PXR_CXX_FLAGS} ${CMAKE_CXX_FLAGS}")
 
+if(PXR_ENABLE_JS_SUPPORT)
+    # Add EMSCRIPTEN specific compiler flags (is this the right place)?
+    set(EMSCRIPTEN_COMPILE_FLAGS "-s ALLOW_MEMORY_GROWTH=1 -s USE_PTHREADS=1 -s PTHREAD_POOL_SIZE=2 -s MODULARIZE=1 -s EXPORT_NAME='getUsdModule' -s 'EXTRA_EXPORTED_RUNTIME_METHODS=[\"FS\"]' -s FORCE_FILESYSTEM=1")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${EMSCRIPTEN_COMPILE_FLAGS}")
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${EMSCRIPTEN_COMPILE_FLAGS}")
+
+    message("EMSCRIPTEN Flags enabled")
+endif()
+
 include(Public)
 
 pxr_toplevel_prologue()

Dockerfile

@@ -0,0 +1,32 @@
+FROM ubuntu:20.04
+SHELL ["/bin/bash", "-c"]
+
+ARG CMAKE_VERSION=3.20.3
+ARG EMSCRIPTEN_VERSION=2.0.24
+
+RUN apt-get -y update && apt-get install -y\
+        python-setuptools \
+        libglew-dev \
+        libxrandr-dev \
+        libxcursor-dev \
+        libxinerama-dev \
+        libxi-dev \        
+        python3-pip \
+        git \
+        curl
+
+RUN curl -fsSL https://deb.nodesource.com/setup_current.x | bash - && DEBIAN_FRONTEND=noninteractive apt-get install -y nodejs libglib2.0-0
+
+RUN pip install --upgrade pip
+RUN pip install PySide2 PyOpenGL Jinja2
+
+# Updating cmake version
+RUN apt remove cmake
+RUN pip install cmake==${CMAKE_VERSION}
+
+RUN mkdir -p tmp && cd tmp && git clone --recursive https://github.com/emscripten-core/emsdk
+RUN cd /tmp/emsdk && ./emsdk install ${EMSCRIPTEN_VERSION}
+RUN cd /tmp/emsdk && ./emsdk activate ${EMSCRIPTEN_VERSION} --permanent
+
+COPY . /src/
+RUN source /tmp/emsdk/emsdk_env.sh && cd /src && python3 ./build_scripts/build_usd.py --emscripten USD_emscripten

build_scripts/build_usd.py

@@ -420,7 +420,8 @@ def RunCMake(context, force, extraArgs = None):
     AppendCXX11ABIArg("-DCMAKE_CXX_FLAGS", context, extraArgs)
 
     with CurrentWorkingDirectory(buildDir):
-        Run('cmake '
+        Run(('emcmake ' if context.emscripten else '') +
+            'cmake '
             '-DCMAKE_INSTALL_PREFIX="{instDir}" '
             '-DCMAKE_PREFIX_PATH="{depsInstDir}" '
             '-DCMAKE_BUILD_TYPE={config} '
@@ -437,7 +438,8 @@ def RunCMake(context, force, extraArgs = None):
                     generator=(generator or ""),
                     toolset=(toolset or ""),
                     extraArgs=(" ".join(extraArgs) if extraArgs else "")))
-        Run("cmake --build . --config {config} --target install -- {multiproc}"
+        Run(('emmake ' if context.emscripten else '') +
+            "cmake --build . --config {config} --target install -- {multiproc}"
             .format(config=config,
                     multiproc=FormatMultiProcs(context.numJobs, generator)))
 
@@ -594,6 +596,8 @@ def DownloadURL(url, context, force, extractDir = None,
                     members = (m for m in archive.getnames() 
                                if not any((fnmatch.fnmatch(m, p)
                                            for p in dontExtract)))
+            elif filename.endswith('.js'):
+                return os.path.abspath(filename)
             else:
                 raise RuntimeError("unrecognized archive file type")
 
@@ -863,8 +867,13 @@ def InstallBoost(context, force, buildArgs):
 else:
     TBB_URL = "https://github.com/oneapi-src/oneTBB/archive/2018_U6.tar.gz"
 
+# Note: this refers to a fork of tbb for wasm. Is this maintained?
+TBB_EMSCRIPTEN_URL = "https://github.com/sdunkel/wasmtbb/archive/master.zip"
+
 def InstallTBB(context, force, buildArgs):
-    if Windows():
+    if context.emscripten:
+        InstallTBB_Emscripten(context, force, buildArgs)
+    elif Windows():
         InstallTBB_Windows(context, force, buildArgs)
     elif Linux() or MacOS():
         InstallTBB_LinuxOrMacOS(context, force, buildArgs)
@@ -912,6 +921,29 @@ def InstallTBB_LinuxOrMacOS(context, force, buildArgs):
         CopyDirectory(context, "include/serial", "include/serial")
         CopyDirectory(context, "include/tbb", "include/tbb")
 
+def InstallTBB_Emscripten(context, force, buildArgs):
+
+    with CurrentWorkingDirectory(DownloadURL(TBB_EMSCRIPTEN_URL, context, force)):
+        # By default no config for macos is avaiable, but the one for linux
+        # seems to work fine
+        if MacOS():
+            shutil.copy('build/linux.emscripten.inc', 'build/macos.emscripten.inc')
+
+        # TBB does not support out-of-source builds in a custom location.
+        Run('emmake make -j{procs} extra_inc=big_iron.inc tbb {buildArgs}'
+            .format(procs=context.numJobs,
+                    buildArgs=" ".join(buildArgs)))
+
+        # Install both release and debug builds. USD requires the debug
+        # libraries when building in debug mode, and installing both
+        # makes it easier for users to install dependencies in some
+        # location that can be shared by both release and debug USD
+        # builds. Plus, the TBB build system builds both versions anyway.
+        CopyFiles(context, "build/*_release/libtbb*.*", "lib")
+        CopyFiles(context, "build/*_debug/libtbb*.*", "lib")
+        CopyDirectory(context, "include/serial", "include/serial")
+        CopyDirectory(context, "include/tbb", "include/tbb")
+
 TBB = Dependency("TBB", InstallTBB, "include/tbb/tbb.h")
 
 ############################################################
@@ -1209,6 +1241,12 @@ def InstallOpenSubdiv(context, force, buildArgs):
             '-DNO_GLEW=ON',
             '-DNO_GLFW=ON',
         ]
+        if context.emscripten:
+            extraArgs.append('-DBUILD_SHARED_LIB=OFF')
+            extraArgs.append('-DCMAKE_CXX_FLAGS="-s USE_PTHREADS=1"')
+            extraArgs.append('-DCMAKE_C_FLAGS="-s USE_PTHREADS=1"')
+            extraArgs.append('-DNO_OPENGL=ON')
+            extraArgs.append('-DNO_METAL=ON')
 
         # If Ptex support is disabled in USD, disable support in OpenSubdiv
         # as well. This ensures OSD doesn't accidentally pick up a Ptex
@@ -1239,7 +1277,7 @@ def InstallOpenSubdiv(context, force, buildArgs):
         # just 1 job for now. See:
         # https://github.com/PixarAnimationStudios/OpenSubdiv/issues/1194
         oldNumJobs = context.numJobs
-        if MacOS():
+        if MacOS() or context.emscripten:
             context.numJobs = 1
 
         try:
@@ -1560,6 +1598,21 @@ def InstallUSD(context, force, buildArgs):
         extraArgs.append('-DBoost_NO_SYSTEM_PATHS=True')
         extraArgs += buildArgs
 
+        if context.emscripten:
+            extraArgs.append('-DPXR_ENABLE_JS_SUPPORT=ON')
+            # For some reason we have to manually specify path to boost
+            extraArgs.append('-DBoost_INCLUDE_DIR='+os.path.join(context.usdInstDir, "include"))
+
+            extraArgs.append('-DTBB_INCLUDE_DIRS=' + os.path.join(context.usdInstDir, 'include'))
+            extraArgs.append('-DTBB_tbb_LIBRARY_DEBUG=' + os.path.join(context.usdInstDir, 'lib/libtbb_debug.a'))
+            extraArgs.append('-DTBB_tbb_LIBRARY_RELEASE=' + os.path.join(context.usdInstDir, 'lib/libtbb.a'))
+
+            extraArgs.append('-DOPENSUBDIV_INCLUDE_DIR=' + os.path.join(context.usdInstDir, 'include'))
+            extraArgs.append('-DOPENSUBDIV_OSDCPU_LIBRARY=' + os.path.join(context.usdInstDir, 'lib/libosdCPU.a'))
+
+            extraArgs.append('-DPXR_ENABLE_GL_SUPPORT=OFF')
+            extraArgs.append('-DBUILD_SHARED_LIBS=OFF')
+
         RunCMake(context, force, extraArgs)
 
 USD = Dependency("USD", InstallUSD, "include/pxr/pxr.h")
@@ -1683,6 +1736,9 @@ def InstallUSD(context, force, buildArgs):
 group.add_argument("--toolset", type=str,
                    help=("CMake toolset to use when building libraries with "
                          "cmake"))
+subgroup = group.add_mutually_exclusive_group()
+subgroup.add_argument("--emscripten", dest="emscripten", action="store_const", const='EMSCRIPTEN',
+                    help="Build for emscripten")
 
 if Linux():
     group.add_argument("--use-cxx11-abi", type=int, choices=[0, 1],
@@ -1892,6 +1948,7 @@ def __init__(self, args):
         # CMake generator and toolset
         self.cmakeGenerator = args.generator
         self.cmakeToolset = args.toolset
+        self.emscripten = args.emscripten
 
         # Number of jobs
         self.numJobs = args.jobs
@@ -2014,9 +2071,45 @@ def ForceBuildDependency(self, dep):
     paths = os.environ.get('PYTHONPATH', '').split(os.pathsep) + extraPythonPaths
     os.environ['PYTHONPATH'] = os.pathsep.join(paths)
 
+# Disable incompatible options if emscripten is used
+if context.emscripten:
+    disabled = []
+    if context.buildPython:
+        context.buildPython = False
+        disabled.append('Python')
+
+    if context.buildImaging:
+        context.buildImaging = NO_IMAGING
+        disabled.append('imaging')
+
+    if context.buildUsdImaging:
+        context.buildUsdImaging = NO_IMAGING
+        disabled.append('usdImaging')
+
+    if context.buildExamples:
+        context.buildExamples = False
+        disabled.append('examples')
+
+    if context.buildTutorials:
+        context.buildTutorials = False
+        disabled.append('tutorials')
+
+    if context.buildTools:
+        context.buildTools = False
+        disabled.append('tools')
+
+    if context.buildUsdview:
+        context.buildUsdview = False
+        disabled.append('usdview')
+
+    if len(disabled) > 0:
+        print("The following components were disabled because they are not compatible with emscripten: " + ", ".join(disabled))
+
 # Determine list of dependencies that are required based on options
 # user has selected.
-requiredDependencies = [ZLIB, BOOST, TBB]
+requiredDependencies = [BOOST, TBB]
+if not context.emscripten:
+    requiredDependencies += [ZLIB]
 
 if context.buildAlembic:
     if context.enableHDF5:
@@ -2054,7 +2147,7 @@ def ForceBuildDependency(self, dep):
 # our own. This avoids potential issues where a host application
 # loads an older version of zlib than the one we'd build and link
 # our libraries against.
-if Linux():
+if Linux() and ZLIB in requiredDependencies:
     requiredDependencies.remove(ZLIB)
 
 # Error out if user is building monolithic library on windows with draco plugin
@@ -2173,6 +2266,7 @@ def _JoinVersion(v):
   Build directory               {buildDir}
   CMake generator               {cmakeGenerator}
   CMake toolset                 {cmakeToolset}
+  Emscripten                    {emscripten}
   Downloader                    {downloader}
 
   Building                      {buildType}
@@ -2232,6 +2326,7 @@ def FormatBuildArguments(buildArgs):
                     else context.cmakeGenerator),
     cmakeToolset=("Default" if not context.cmakeToolset
                   else context.cmakeToolset),
+    emscripten=("Enabled" if context.emscripten else "Disabled"),
     downloader=(context.downloaderName),
     dependencies=("None" if not dependenciesToBuild else 
                   ", ".join([d.name for d in dependenciesToBuild])),

cmake/defaults/Options.cmake

@@ -40,6 +40,7 @@ option(PXR_BUILD_PRMAN_PLUGIN "Build the PRMan imaging plugin" OFF)
 option(PXR_ENABLE_MATERIALX_SUPPORT "Enable MaterialX support" OFF)
 option(PXR_BUILD_DOCUMENTATION "Generate doxygen documentation" OFF)
 option(PXR_ENABLE_PYTHON_SUPPORT "Enable Python based components for USD" ON)
+option(PXR_ENABLE_JS_SUPPORT "Enable Javascript based components for USD" OFF)
 option(PXR_USE_PYTHON_3 "Build Python bindings for Python 3" OFF)
 option(PXR_USE_DEBUG_PYTHON "Build with debug python" OFF)
 option(PXR_ENABLE_HDF5_SUPPORT "Enable HDF5 backend in the Alembic plugin for USD" ON)
@@ -186,3 +187,10 @@ if (${PXR_BUILD_DRACO_PLUGIN} AND ${PXR_BUILD_MONOLITHIC} AND WIN32)
     message(FATAL_ERROR 
         "Draco plugin can not be enabled for monolithic builds on Windows")
 endif()
+
+# Error out if user is building with Emscripten and tests. 
+# This is currently not supported.
+if (${PXR_ENABLE_JS_SUPPORT} AND ${PXR_BUILD_TESTS})
+    message(FATAL_ERROR 
+        "Emscripten build can not be enabled together with tests")
+endif()

cmake/defaults/Packages.cmake

@@ -120,6 +120,15 @@ else()
             find_package(PythonInterp 2.7 REQUIRED)
         endif()
     endif()
+
+    # --Boost
+    if(NOT PXR_ENABLE_JS_SUPPORT)
+        find_package(Boost
+            COMPONENTS
+                program_options
+            REQUIRED
+        )
+    endif()
 endif()
 
 # --USD tools

cmake/macros/Private.cmake

@@ -249,14 +249,26 @@ function(_install_resource_files NAME pluginInstallPrefix pluginToLibraryPath)
                 _plugInfo_subst(${NAME} "${pluginToLibraryPath}" ${resourceFile})
             endif()
             set(resourceFile "${CMAKE_CURRENT_BINARY_DIR}/${resourceFile}")
+            set(EMSCRIPTEN_RESOURCE_FILE ${resourceFile})
+        else()
+            set(EMSCRIPTEN_RESOURCE_FILE "${CMAKE_CURRENT_SOURCE_DIR}/${resourceFile}")
         endif()
 
+        if (PXR_ENABLE_JS_SUPPORT)
+            string(REGEX REPLACE "^lib\\/" "/" LOCAL_PATH "${resourcesPath}")
+
+            list(APPEND EMSCRIPTEN_RESOURCE_FILES "--embed-file ${EMSCRIPTEN_RESOURCE_FILE}@${LOCAL_PATH}/${dirPath}/${destFileName}")
+        endif()
         install(
             FILES ${resourceFile}
             DESTINATION ${resourcesPath}/${dirPath}
             RENAME ${destFileName}
         )
     endforeach()
+
+    if (PXR_ENABLE_JS_SUPPORT)
+        set_property(TARGET ${NAME} PROPERTY EMSCRIPTEN_RESOURCES ${EMSCRIPTEN_RESOURCE_FILES})
+    endif()
 endfunction() # _install_resource_files
 
 function(_install_pyside_ui_files LIBRARY_NAME)
@@ -854,6 +866,8 @@ function(_pxr_target_link_libraries NAME)
                     list(APPEND final ${lib})
                 elseif(CMAKE_COMPILER_IS_GNUCXX)
                     list(APPEND final -Wl,--whole-archive ${lib} -Wl,--no-whole-archive)
+                elseif(PXR_ENABLE_JS_SUPPORT)
+                    list(APPEND final -Wl,--whole-archive ${lib} -Wl,--no-whole-archive)
                 elseif("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
                     list(APPEND final -Wl,-force_load ${lib})
                 else()

cmake/macros/Public.cmake

@@ -236,6 +236,11 @@ function(pxr_library NAME)
         PYMODULE_CPPFILES
         PYMODULE_FILES
         PYSIDE_UI_FILES
+        JS_PUBLIC_CLASSES
+        JS_PRIVATE_CLASSES
+        JS_PUBLIC_HEADERS
+        JS_PRIVATE_HEADERS
+        JS_CPPFILES
     )
 
     cmake_parse_arguments(args
@@ -265,6 +270,24 @@ function(pxr_library NAME)
         endif()
     endif()
 
+    if(PXR_ENABLE_JS_SUPPORT)
+        if(args_JS_PUBLIC_CLASSES)
+            list(APPEND args_PUBLIC_CLASSES ${args_JS_PUBLIC_CLASSES})
+        endif()
+        if(args_JS_PUBLIC_HEADERS)
+            list(APPEND args_PUBLIC_HEADERS ${args_JS_PUBLIC_HEADERS})
+        endif()
+        if(args_JS_PRIVATE_CLASSES)
+            list(APPEND args_PRIVATE_CLASSES ${args_JS_PRIVATE_CLASSES})
+        endif()
+        if(args_JS_PRIVATE_HEADERS)
+            list(APPEND args_PRIVATE_HEADERS ${args_JS_PRIVATE_HEADERS})
+        endif()
+        if(args_JS_CPPFILES)
+            list(APPEND args_CPPFILES ${args_JS_CPPFILES})
+        endif()
+    endif()
+
     # Collect libraries.
     if(NOT args_TYPE STREQUAL "PLUGIN")
         get_property(help CACHE PXR_ALL_LIBS PROPERTY HELPSTRING)

extras/usd/CMakeLists.txt

@@ -4,3 +4,6 @@ endif()
 if (PXR_BUILD_EXAMPLES)
     add_subdirectory(examples)
 endif()
+if (PXR_ENABLE_JS_SUPPORT)
+  add_subdirectory(js_bindings)
+endif()