undefined symbol: glDrawBuffer, etc.

[effepivi]

Hello,

I am trying to use Emscripten with an existing CMake project. Offline rendering is used with OpenGL.
I got errors during the linkage:

wasm-ld: error: ...: undefined symbol: glDrawBuffer
wasm-ld: error: ...: undefined symbol: glReadBuffer
wasm-ld: error: ...: undefined symbol: glGetTexLevelParameteriv
wasm-ld: error: ...: undefined symbol: glTexImage3D
wasm-ld: error: ...: undefined symbol: glGetTexImage

Any help will be welcome.

[kripken]

-sLEGACY_GL_EMULATION is needed for glGetTexLevelParameteriv. You may also need -lGL.

[effepivi]

Thanks. I made some progress, but still getting linkage errors with:

glTexImage3D, glTexImage3D, glFramebufferTexture1D and glFramebufferTexture3D.

I added the options mentioned above in target_link_libraries and in CMAKE_EXE_LINKER_FLAGS. Was it what I was meant to do?

[effepivi]

Further, I added -s ERROR_ON_UNDEFINED_SYMBOLS=0. It links but ignore the errors, not sure yet what will the consequences be.
When I load the .js file, I get another error, but that's another story:
Cannot enlarge memory, requested 2239266816 bytes, but the limit is 2147483648 bytes!

[kripken]

glTexImage3D is part of WebGL 2.0, so you may need to enable that (-sMAX_WEBGL_VERSION=2)