Emscripten build issues and build instructions

[rendaw]

First of all, AFAICT from git history the project switched from a handmade Makefile to CMake recently and it looks like the build instructions on the wiki are out of date.

I'm trying to build the WASM version, I use these commands:

emcmake cmake . && emmake make

but linking tic80.js fails with:

[ 85%] Linking CXX executable bin/tic80.js
/usr/bin/cmake -E cmake_link_script CMakeFiles/tic80.dir/link.txt --verbose=1
/usr/lib/emscripten/em++     @CMakeFiles/tic80.dir/objects1.rsp  -o bin/tic80.js @CMakeFiles/tic80.dir/linklibs.rsp
warning: unexpected number of arguments 1 in call to 'getClipboardEvent', should be 0
error: undefined symbol: SDL_BuildAudioCVT
warning: To disable errors for undefined symbols use `-s ERROR_ON_UNDEFINED_SYMBOLS=0`
error: undefined symbol: SDL_CloseAudioDevice
error: undefined symbol: SDL_ConvertAudio
error: undefined symbol: SDL_CreateSystemCursor
error: undefined symbol: SDL_CreateWindow
error: undefined symbol: SDL_GL_CreateContext
error: undefined symbol: SDL_GL_GetDrawableSize
error: undefined symbol: SDL_GetClipboardText
error: undefined symbol: SDL_GetColorKey
error: undefined symbol: SDL_GetPerformanceCounter
error: undefined symbol: SDL_GetPerformanceFrequency
error: undefined symbol: SDL_GetWindowFromID
error: undefined symbol: SDL_GetWindowID
error: undefined symbol: SDL_HasClipboardText
error: undefined symbol: SDL_JoystickGetAttached
error: undefined symbol: SDL_OpenAudioDevice
error: undefined symbol: SDL_PauseAudioDevice
error: undefined symbol: SDL_QueueAudio
error: undefined symbol: SDL_SetClipboardText
error: undefined symbol: SDL_SetCursor
error: undefined symbol: SDL_SetHint
error: undefined symbol: SDL_SetWindowIcon
error: undefined symbol: SDL_SetWindowSize
error: undefined symbol: SDL_ShowSimpleMessageBox
error: undefined symbol: SDL_memcpy
error: undefined symbol: glColor4f
error: undefined symbol: glColor4ub
error: undefined symbol: glEnd
error: undefined symbol: glGetTexImage
error: undefined symbol: glGetTexLevelParameteriv
error: undefined symbol: glLoadMatrixf
error: undefined symbol: glTexCoord2f
error: undefined symbol: glVertex3f
error: undefined symbol: glXGetClientString
error: undefined symbol: glXGetProcAddressARB
error: undefined symbol: glXQueryVersion
Error: Aborting compilation due to previous errors
ERROR:root:'/usr/bin/node /usr/lib/emscripten/src/compiler.js /tmp/tmpr74l339j.txt /usr/lib/emscripten/src/library_pthread_stub.js' failed (1)

$ cat CMakeFiles/tic80.dir/objects1.rsp 
CMakeFiles/tic80.dir/src/net.c.o CMakeFiles/tic80.dir/src/system.c.o CMakeFiles/tic80.dir/src/ext/file_dialog.c.o
$ cat CMakeFiles/tic80.dir/linklibs.rsp 
lib/libtic80lib.a lib/libsdlnet.a lib/libsdlgpu.a lib/libtic80core.a lib/liblua.a lib/liblpeg.a lib/libwren.a lib/libsquirrel.a lib/libgiflib.a lib/libzlib.a

I can't say I'm familiar with emscripten and I've made about a million mistakes getting this far so it's possible I missed something. I thought the SDL_ ones at least would have been built by 3rd-party/sdl-gpu... I see that compiled into a .a file earlier in the log.

Glad to update the wiki if someone can help me get this working.

Linux
cmake 3.12.4
emcc 1.38.15

[rendaw]

AFAICT the gl symbol errors are due to https://github.com/nesbox/TIC-80/blob/master/CMakeLists.txt#L289
DSDL_GPU_DISABLE_OPENGL should be SDL_GPU_DISABLE_OPENGL. Can anyone confirm?

Still stuck with the SDL_ symbol errors though.

[rendaw]

Ah, it looks like -s USE_SDL=2 needs to be in the linking as well:

-       if(NOT EMSCRIPTEN)
+       if(EMSCRIPTEN)
+               target_link_libraries(${TIC80_OUTPUT} "-s USE_SDL=2")
+       else()
                add_dependencies(${TIC80_OUTPUT} SDL2main SDL2-static)
                target_link_libraries(${TIC80_OUTPUT} SDL2-static SDL2main)
        endif()

https://github.com/nesbox/TIC-80/blob/master/CMakeLists.txt#L482

Is my system nonstandard in this regard? Anyway, leaving the information here in case someone else has the issue. I'll close this in a few days if there's no interest.

[rendaw]

It looks like -s TOTAL_MEMORY also needs to be in the link flags? I'm getting errors about 16mb memory limit without.

[nesbox]

Fixed Emscripten build.
Thank you.