[javascript] Add TI_EMSCRIPTENED to cmake options (JS 1/n) (#4093)

cmake/TaichiCore.cmake

@@ -7,6 +7,19 @@ option(TI_WITH_OPENGL "Build with the OpenGL backend" ON)
 option(TI_WITH_CC "Build with the C backend" ON)
 option(TI_WITH_VULKAN "Build with the Vulkan backend" OFF)
 option(TI_WITH_DX11 "Build with the DX11 backend" OFF)
+option(TI_EMSCRIPTENED "Build using emscripten" OFF)
+
+if(TI_EMSCRIPTENED)
+    set(TI_WITH_LLVM OFF)
+    set(TI_WITH_METAL OFF)
+    set(TI_WITH_CUDA OFF)
+    set(TI_WITH_OPENGL OFF)
+    set(TI_WITH_CC OFF)
+    set(TI_WITH_DX11 OFF)
+
+    set(TI_WITH_VULKAN ON)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DTI_EMSCRIPTENED")
+endif()
 
 if(UNIX AND NOT APPLE)
     # Handy helper for Linux
@@ -37,7 +50,7 @@ if (WIN32)
 endif()
 
 set(TI_WITH_GGUI OFF)
-if(TI_WITH_VULKAN)
+if(TI_WITH_VULKAN AND NOT TI_EMSCRIPTENED)
     set(TI_WITH_GGUI ON)
 endif()
 
@@ -190,6 +203,12 @@ file(GLOB TAICHI_PYBIND_SOURCE
 )
 list(REMOVE_ITEM TAICHI_CORE_SOURCE ${TAICHI_PYBIND_SOURCE})
 
+file(GLOB TAICHI_EMBIND_SOURCE
+      "taichi/javascript/*.cpp"
+      "taichi/javascript/*.h"
+)
+list(REMOVE_ITEM TAICHI_CORE_SOURCE ${TAICHI_EMBIND_SOURCE})
+
 # TODO(#2196): Rename these CMAKE variables:
 # CORE_LIBRARY_NAME --> TAICHI_ISOLATED_CORE_LIB_NAME
 # CORE_WITH_PYBIND_LIBRARY_NAME --> TAICHI_CORE_LIB_NAME
@@ -220,7 +239,7 @@ endif()
 set(LIBRARY_NAME ${CORE_LIBRARY_NAME})
 
 # GLFW not available on Android
-if (TI_WITH_OPENGL OR TI_WITH_VULKAN AND NOT ANDROID)
+if (TI_WITH_OPENGL OR TI_WITH_VULKAN AND NOT ANDROID AND NOT TI_EMSCRIPTENED)
   set(GLFW_BUILD_DOCS OFF CACHE BOOL "" FORCE)
   set(GLFW_BUILD_TESTS OFF CACHE BOOL "" FORCE)
   set(GLFW_BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
@@ -383,28 +402,39 @@ endforeach ()
 
 message("PYTHON_LIBRARIES: " ${PYTHON_LIBRARIES})
 
-set(CORE_WITH_PYBIND_LIBRARY_NAME taichi_core)
-# Cannot compile Python source code with Android, but TI_EXPORT_CORE should be set and
-# Android should only use the isolated library ignoring those source code.
-if (NOT ANDROID)
-    add_library(${CORE_WITH_PYBIND_LIBRARY_NAME} SHARED ${TAICHI_PYBIND_SOURCE})
-else()
-    add_library(${CORE_WITH_PYBIND_LIBRARY_NAME} SHARED)
-endif ()
-# It is actually possible to link with an OBJECT library
-# https://cmake.org/cmake/help/v3.13/command/target_link_libraries.html?highlight=target_link_libraries#linking-object-libraries
-target_link_libraries(${CORE_WITH_PYBIND_LIBRARY_NAME} PUBLIC ${CORE_LIBRARY_NAME})
-
-# These commands should apply to the DLL that is loaded from python, not the OBJECT library.
-if (MSVC)
-    set_property(TARGET ${CORE_WITH_PYBIND_LIBRARY_NAME} APPEND PROPERTY LINK_FLAGS /DEBUG)
-endif ()
-
-if (WIN32)
-    set_target_properties(${CORE_WITH_PYBIND_LIBRARY_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY
-            "${CMAKE_CURRENT_SOURCE_DIR}/runtimes")
-endif ()
+if(NOT TI_EMSCRIPTENED)
+    set(CORE_WITH_PYBIND_LIBRARY_NAME taichi_core)
+    # Cannot compile Python source code with Android, but TI_EXPORT_CORE should be set and
+    # Android should only use the isolated library ignoring those source code.
+    if (NOT ANDROID)
+        add_library(${CORE_WITH_PYBIND_LIBRARY_NAME} SHARED ${TAICHI_PYBIND_SOURCE})
+    else()
+        add_library(${CORE_WITH_PYBIND_LIBRARY_NAME} SHARED)
+    endif ()
+    # It is actually possible to link with an OBJECT library
+    # https://cmake.org/cmake/help/v3.13/command/target_link_libraries.html?highlight=target_link_libraries#linking-object-libraries
+    target_link_libraries(${CORE_WITH_PYBIND_LIBRARY_NAME} PUBLIC ${CORE_LIBRARY_NAME})
+
+    # These commands should apply to the DLL that is loaded from python, not the OBJECT library.
+    if (MSVC)
+        set_property(TARGET ${CORE_WITH_PYBIND_LIBRARY_NAME} APPEND PROPERTY LINK_FLAGS /DEBUG)
+    endif ()
+
+    if (WIN32)
+        set_target_properties(${CORE_WITH_PYBIND_LIBRARY_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY
+                "${CMAKE_CURRENT_SOURCE_DIR}/runtimes")
+    endif ()
+endif()
 
+if(TI_EMSCRIPTENED)
+    set(CORE_WITH_EMBIND_LIBRARY_NAME taichi)
+    add_executable(${CORE_WITH_EMBIND_LIBRARY_NAME} ${TAICHI_EMBIND_SOURCE})
+    target_link_libraries(${CORE_WITH_EMBIND_LIBRARY_NAME} PUBLIC ${CORE_LIBRARY_NAME})
+    target_compile_options(${CORE_WITH_EMBIND_LIBRARY_NAME} PRIVATE "-Oz")
+    # target_compile_options(${CORE_LIBRARY_NAME} PRIVATE "-Oz")
+    set_target_properties(${CORE_LIBRARY_NAME} PROPERTIES LINK_FLAGS "-s ERROR_ON_UNDEFINED_SYMBOLS=0 -s ASSERTIONS=1")
+    set_target_properties(${CORE_WITH_EMBIND_LIBRARY_NAME} PROPERTIES LINK_FLAGS "--bind -s MODULARIZE=1 -s EXPORT_NAME=createTaichiModule -s WASM=0  --memory-init-file 0 -Oz --closure 1 -s ERROR_ON_UNDEFINED_SYMBOLS=0 -s ASSERTIONS=1 -s NO_DISABLE_EXCEPTION_CATCHING")
+endif()
 
 if(TI_WITH_GGUI)
     include_directories(SYSTEM PRIVATE external/glm)

cmake/TaichiExamples.cmake

@@ -1,5 +1,7 @@
 cmake_minimum_required(VERSION 3.0)
 
+if(NOT TI_EMSCRIPTENED)
+
 set(EXAMPLES_NAME taichi_cpp_examples)
 
 file(GLOB_RECURSE TAICHI_EXAMPLES_SOURCE
@@ -24,3 +26,5 @@ if (WIN32)
     set_target_properties(${EXAMPLES_NAME} PROPERTIES RUNTIME_OUTPUT_DIRECTORY_RELWITHDEBINFO ${EXAMPLES_OUTPUT_DIR})
 endif()
 target_link_libraries(${EXAMPLES_NAME} taichi_isolated_core)
+
+endif()