Missing documentation for building using emscripten #2812

gracicot · 2022-06-02T16:06:05Z

gracicot
Jun 2, 2022

Describe the bug
The documentation for building bgfx to webassembly using emscripten is missing.

To Reproduce
Steps to reproduce the behavior:

Go to https://bkaradzic.github.io/bgfx/
Search for instruction for compiling to WASM using emscripten
Notice to lack of documentation for this supported platform

Expected behavior
A clear documentation for building to webassembly should be present. It should contain:

The expected emscripten version
How to enable features such as the target api platform (like webgpu, webgl)
What command to type to build bgfx
How to run the example in the browser

What I tried
Here's what I tried for now despite the lack of instructions, and what issues I've encountered.

First, building bgfx with genie:

I have emscripten installed on my computer following the instructions here: https://emscripten.org/docs/getting_started/downloads.html
Emscripten version 3.1.12
MacOS 11.5.1 (x86_64)
CMake 3.22 (nix)
Ninja 1.10.2 (nix)
Xcode version 13.2.1

make wasm-debug

An error encountered:

==== Building bx (debug) ====
Creating ../../wasm/obj/Debug/bx
Creating ../../wasm/obj/Debug/bx/bx/src
Creating ../../wasm/bin
allocator.cpp
/bin/sh: /em++: No such file or directory
make[2]: *** [../../wasm/obj/Debug/bx/bx/src/allocator.o] Error 127
make[1]: *** [bx] Error 2
make: *** [wasm-debug] Error 2

Reason: emsdk (the supported installation instruction from emscripten) don't set the environment variable EMSCRIPTEN, and their official docker image don't set that variable either, and the make scripts assume that variable exists instead of taking em++ from PATH

Fix: Set manually the EMSCRIPTEN environment variable or change how bgfx.make is generated so that those lines:

CC  = "$(EMSCRIPTEN)/emcc"
CXX = "$(EMSCRIPTEN)/em++"
AR  = "$(EMSCRIPTEN)/emar"

becomes

CC  = "emcc"
CXX = "em++"
AR  = "emar"

Environment variable manually set then make wasm-debug again

Another error:

==== Building example-17-drawstress (debug) ====
Creating ../../wasm/obj/Debug/example-17-drawstress
Creating ../../wasm/obj/Debug/example-17-drawstress/examples/17-drawstress
drawstress.cpp
../../../examples/17-drawstress/drawstress.cpp:98:24: error: no type named 'Thread' in namespace 'bx'
int32_t threadFunc(bx::Thread* _thread, void* _userData);
                   ~~~~^
../../../examples/17-drawstress/drawstress.cpp:204:21: error: no type named 'Thread' in namespace 'bx'
        int32_t thread(bx::Thread* _thread)
                       ~~~~^
../../../examples/17-drawstress/drawstress.cpp:446:6: error: no type named 'Thread' in namespace 'bx'
        bx::Thread m_thread[5];
        ~~~~^
../../../examples/17-drawstress/drawstress.cpp:339:4: error: no matching function for call to 'showExampleDialog'
                        showExampleDialog(this);
                        ^~~~~~~~~~~~~~~~~
../../../examples/common/imgui/imgui.h:37:6: note: candidate function not viable: no known conversion from '(anonymous namespace)::ExampleDrawStress *' to 'entry::AppI *' for 1st argument
void showExampleDialog(entry::AppI* _app, const char* _errorText = NULL);
     ^
../../../examples/17-drawstress/drawstress.cpp:454:24: error: no type named 'Thread' in namespace 'bx'
int32_t threadFunc(bx::Thread* _thread, void* _userData)
                   ~~~~^
../../../examples/17-drawstress/drawstress.cpp:462:1: error: cannot initialize a parameter of type 'entry::AppI *' with an rvalue of type '(anonymous namespace)::ExampleDrawStress *'
ENTRY_IMPLEMENT_MAIN(
^~~~~~~~~~~~~~~~~~~~~
../../../examples/common/entry/entry.h:31:25: note: expanded from macro 'ENTRY_IMPLEMENT_MAIN'
                        return entry::runApp(&app, _argc, _argv);   \
                                             ^~~~
../../../examples/common/entry/entry.h:326:19: note: passing argument to parameter '_app' here
        int runApp(AppI* _app, int _argc, const char* const* _argv);
                         ^
6 errors generated.
em++: error: '/Users/grc/Workspace/github/emsdk/upstream/bin/clang++ -target wasm32-unknown-emscripten -DEMSCRIPTEN -D__EMSCRIPTEN_major__=3 -D__EMSCRIPTEN_minor__=1 -D__EMSCRIPTEN_tiny__=12 -fignore-exceptions -fvisibility=default -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr -Werror=implicit-function-declaration -Xclang -iwithsysroot/include/SDL --sysroot=/Users/grc/Workspace/github/emsdk/upstream/emscripten/cache/sysroot -Xclang -iwithsysroot/include/compat -MMD -MP -MP -D__STDC_LIMIT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS -D_DEBUG -DENTRY_CONFIG_IMPLEMENT_MAIN=1 -DBX_CONFIG_DEBUG=1 -I../../../../bimg/include -I../../../include -I../../../3rdparty -I../../../examples/common -I../../../../bx/include -Wall -Wextra -ffast-math -fomit-frame-pointer -g3 -Werror -O2 -std=c++14 -fno-rtti -fno-exceptions -Wunused-value -Wundef -c ../../../examples/17-drawstress/drawstress.cpp -o ../../wasm/obj/Debug/example-17-drawstress/examples/17-drawstress/drawstress.o' failed (returned 1)
make[2]: *** [../../wasm/obj/Debug/example-17-drawstress/examples/17-drawstress/drawstress.o] Error 1
make[1]: *** [example-17-drawstress] Error 2
make: *** [wasm-debug] Error 2

Without knowing how to disable threading with genie, I decided to use bgfx.cmake which exposes the option

Then , I Cloned the bgfx.cmake repo and moved in it

mkdir build && cd build
cmake .. -DCMAKE_TOOLCHAIN_FILE=/path/to/emsdk/upstream/emscripten/cmake/Modules/Platform/Emscripten.cmake -G"Ninja Multi-Config" -DBGFX_CONFIG_MULTITHREADED=OFF -DBGFX_INSTALL_EXAMPLES=ON
The -DBGFX_INSTALL_EXAMPLES=ON was required to build the examples, even if -DDBGFX_BUILD_EXAMPLES=ON is set

cmake --build . --config=Debug

Error with the following output

[12/92] Linking CXX executable Debug/example-35-dynamic.js
FAILED: Debug/example-35-dynamic.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-35-dynamic.dir/Debug/bgfx/examples/35-dynamic/dynamic.cpp.o -o Debug/example-35-dynamic.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmpe6xeqdzf.json' failed (returned 1)
[13/92] Linking CXX executable Debug/example-34-mvs.js
FAILED: Debug/example-34-mvs.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-34-mvs.dir/Debug/bgfx/examples/34-mvs/mvs.cpp.o -o Debug/example-34-mvs.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmpvkv9tp_p.json' failed (returned 1)
[14/92] Linking CXX executable Debug/example-38-bloom.js
FAILED: Debug/example-38-bloom.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-38-bloom.dir/Debug/bgfx/examples/38-bloom/bloom.cpp.o -o Debug/example-38-bloom.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmp3ls2tznp.json' failed (returned 1)
[15/92] Linking CXX executable Debug/example-31-rsm.js
FAILED: Debug/example-31-rsm.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-31-rsm.dir/Debug/bgfx/examples/31-rsm/reflectiveshadowmap.cpp.o -o Debug/example-31-rsm.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmpwxo9h843.json' failed (returned 1)
[16/92] Linking CXX executable Debug/example-30-picking.js
FAILED: Debug/example-30-picking.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-30-picking.dir/Debug/bgfx/examples/30-picking/picking.cpp.o -o Debug/example-30-picking.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmppc6zm_v3.json' failed (returned 1)
[17/92] Linking CXX executable Debug/example-33-pom.js
FAILED: Debug/example-33-pom.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-33-pom.dir/Debug/bgfx/examples/33-pom/pom.cpp.o -o Debug/example-33-pom.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmp1oenky49.json' failed (returned 1)
[18/92] Linking CXX executable Debug/example-39-assao.js
FAILED: Debug/example-39-assao.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-39-assao.dir/Debug/bgfx/examples/39-assao/assao.cpp.o -o Debug/example-39-assao.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmpxczefbgd.json' failed (returned 1)
[19/92] Linking CXX executable Debug/example-32-particles.js
FAILED: Debug/example-32-particles.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-32-particles.dir/Debug/bgfx/examples/32-particles/particles.cpp.o -o Debug/example-32-particles.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmpiolvpk36.json' failed (returned 1)
[20/92] Linking CXX executable Debug/example-36-sky.js
FAILED: Debug/example-36-sky.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-36-sky.dir/Debug/bgfx/examples/36-sky/sky.cpp.o -o Debug/example-36-sky.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmpsuk4w16i.json' failed (returned 1)
[21/92] Linking CXX executable Debug/example-40-svt.js
FAILED: Debug/example-40-svt.js
: && workspace/emsdk/upstream/emscripten/em++ -g  CMakeFiles/example-40-svt.dir/Debug/bgfx/examples/40-svt/svt.cpp.o CMakeFiles/example-40-svt.dir/Debug/bgfx/examples/40-svt/vt.cpp.o -o Debug/example-40-svt.js  Debug/libexample-common.a  -s PRECISE_F32=1  -s TOTAL_MEMORY=268435456  --memory-init-file 1  Debug/libbgfx.a  Debug/libbimg.a  Debug/libastc-codec.a  Debug/libastc.a  Debug/libedtaa3.a  Debug/libetc1.a  Debug/libetc2.a  Debug/libiqa.a  Debug/libsquish.a  Debug/libnvtt.a  Debug/libpvrtc.a  Debug/libtinyexr.a  Debug/libdear-imgui.a  Debug/libbx.a  -ldl  -lrt  Debug/libmeshoptimizer.a  -lX11 && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/font workspace/bgfx.cmake/build/Debug/font && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/images workspace/bgfx.cmake/build/Debug/images && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/meshes workspace/bgfx.cmake/build/Debug/meshes && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/shaders workspace/bgfx.cmake/build/Debug/shaders && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/text workspace/bgfx.cmake/build/Debug/text && cd workspace/bgfx.cmake/build && /nix/store/hpld3wyf2ap36gld4sxa2hc2brrlkjfn-cmake-3.22.3/bin/cmake -E create_symlink workspace/bgfx.cmake/bgfx/examples/runtime/textures workspace/bgfx.cmake/build/Debug/textures
error: undefined symbol: emscripten_webgl2_get_proc_address (referenced by top-level compiled C/C++ code)
warning: Link with `-sLLD_REPORT_UNDEFINED` to get more information on undefined symbols
warning: To disable errors for undefined symbols use `-sERROR_ON_UNDEFINED_SYMBOLS=0`
warning: _emscripten_webgl2_get_proc_address may need to be added to EXPORTED_FUNCTIONS if it arrives from a system library
Error: Aborting compilation due to previous errors
em++: error: 'workspace/emsdk/node/14.18.2_64bit/bin/node workspace/emsdk/upstream/emscripten/src/compiler.js /var/folders/vy/xby6hsz97j184x77rhcsnfk80000gn/T/tmpkedszl0i.json' failed (returned 1)
ninja: build stopped: subcommand failed.

What are the instructions to build the example using web assembly? What are the requirements to start developing with bgfx using emscripten? It seems like the current documentation is lacking.

If someone knows how to build for the webassembly platform, instructions on how to build the examples would be highly appreciated 🙏 I am willing to help with documentation efforts if I can successfully build bgfx and examples with emscripten.

bkaradzic · 2022-06-02T17:13:25Z

bkaradzic
Jun 2, 2022
Maintainer

Just set EMSCRIPTEN variable to where Emscripten is installed...

9 replies

gracicot Jun 2, 2022
Author

I did set env variable EMSCRIPTEN after I got the first error, as I described in my post. There is multiple issue I encountered.

Here's the output in my console of echo $EMSCRIPTEN (copy pasted whole output of my console):

❯ echo $EMSCRIPTEN
/Users/grc/Workspace/github/emsdk/upstream/emscripten

Then, I called make wasm-debug, here's the whole output:

❯ make wasm-debug
/Applications/Xcode.app/Contents/Developer/usr/bin/make -R -C .build/projects/gmake-wasm config=debug
==== Building bx (debug) ====
==== Building bgfx (debug) ====
==== Building bimg (debug) ====
==== Building bimg_decode (debug) ====
==== Building example-glue (debug) ====
==== Building example-common (debug) ====
==== Building example-17-drawstress (debug) ====
drawstress.cpp
../../../examples/17-drawstress/drawstress.cpp:98:24: error: no type named 'Thread' in namespace 'bx'
int32_t threadFunc(bx::Thread* _thread, void* _userData);
                   ~~~~^
../../../examples/17-drawstress/drawstress.cpp:204:21: error: no type named 'Thread' in namespace 'bx'
        int32_t thread(bx::Thread* _thread)
                       ~~~~^
../../../examples/17-drawstress/drawstress.cpp:446:6: error: no type named 'Thread' in namespace 'bx'
        bx::Thread m_thread[5];
        ~~~~^
../../../examples/17-drawstress/drawstress.cpp:339:4: error: no matching function for call to 'showExampleDialog'
                        showExampleDialog(this);
                        ^~~~~~~~~~~~~~~~~
../../../examples/common/imgui/imgui.h:37:6: note: candidate function not viable: no known conversion from '(anonymous namespace)::ExampleDrawStress *' to 'entry::AppI *' for 1st argument
void showExampleDialog(entry::AppI* _app, const char* _errorText = NULL);
     ^
../../../examples/17-drawstress/drawstress.cpp:454:24: error: no type named 'Thread' in namespace 'bx'
int32_t threadFunc(bx::Thread* _thread, void* _userData)
                   ~~~~^
../../../examples/17-drawstress/drawstress.cpp:462:1: error: cannot initialize a parameter of type 'entry::AppI *' with an rvalue of type '(anonymous namespace)::ExampleDrawStress *'
ENTRY_IMPLEMENT_MAIN(
^~~~~~~~~~~~~~~~~~~~~
../../../examples/common/entry/entry.h:31:25: note: expanded from macro 'ENTRY_IMPLEMENT_MAIN'
                        return entry::runApp(&app, _argc, _argv);   \
                                             ^~~~
../../../examples/common/entry/entry.h:326:19: note: passing argument to parameter '_app' here
        int runApp(AppI* _app, int _argc, const char* const* _argv);
                         ^
6 errors generated.
em++: error: '/Users/grc/Workspace/github/emsdk/upstream/bin/clang++ -target wasm32-unknown-emscripten -DEMSCRIPTEN -D__EMSCRIPTEN_major__=3 -D__EMSCRIPTEN_minor__=1 -D__EMSCRIPTEN_tiny__=12 -fignore-exceptions -fvisibility=default -mllvm -combiner-global-alias-analysis=false -mllvm -enable-emscripten-sjlj -mllvm -disable-lsr -Werror=implicit-function-declaration -Xclang -iwithsysroot/include/SDL --sysroot=/Users/grc/Workspace/github/emsdk/upstream/emscripten/cache/sysroot -Xclang -iwithsysroot/include/compat -MMD -MP -MP -D__STDC_LIMIT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_CONSTANT_MACROS -D_DEBUG -DENTRY_CONFIG_IMPLEMENT_MAIN=1 -DBX_CONFIG_DEBUG=1 -I../../../../bimg/include -I../../../include -I../../../3rdparty -I../../../examples/common -I../../../../bx/include -Wall -Wextra -ffast-math -fomit-frame-pointer -g3 -Werror -O2 -std=c++14 -fno-rtti -fno-exceptions -Wunused-value -Wundef -c ../../../examples/17-drawstress/drawstress.cpp -o ../../wasm/obj/Debug/example-17-drawstress/examples/17-drawstress/drawstress.o' failed (returned 1)
make[2]: *** [../../wasm/obj/Debug/example-17-drawstress/examples/17-drawstress/drawstress.o] Error 1
make[1]: *** [example-17-drawstress] Error 2
make: *** [wasm-debug] Error 2

Maybe there are other problems with CMake but I'm not sure how to fix the issue with make as I'm unfamiliar with GENie.

gracicot Jun 2, 2022
Author

Maybe I should have opened different issues for each individual problem instead of having put everything in the same one to avoid confusion

bkaradzic Jun 2, 2022
Maintainer

Skip building 17-drawstress... It doesn't work on web...

bkaradzic Jun 2, 2022
Maintainer

Actually grab latest I removed example-17-drawstress from Emscripten build from GENie script.

gracicot Jun 2, 2022
Author

Oh cool! Yeah, I figured there was an issue somewhere that prevented me to build using GENie scripts. Thanks for fixing this!

d3fault · 2025-02-18T17:57:12Z

d3fault
Feb 18, 2025

https://github.com/d3fault/bgfx-glfw-wasm-3dcube-template-starting-point

0 replies

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Missing documentation for building using emscripten #2812

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Missing documentation for building using emscripten #2812

gracicot Jun 2, 2022

Replies: 2 comments · 9 replies

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