VTK + QT in emscripten webassembly: opengl ERROR: unknown type name 'PFNGLPUSHDEBUGGROUPPROC'; did you mean 'PFNGLPUSHDEBUGGROUPKHRPROC'

Support
1

Our previous developer left but he only gave a little information on how he built the project in QT, but we saw that it was built succesfuly as we have seen it runing as a web page (our desktop QT that is).

here is what I did:

  1. I downloaded QT as an installer

  2. After download, I ran the Maintenance tool, Went to add or remove components.
    I Installed QT 6.5.0 and the platflorms
    MinGW 11.2.0 64 bit
    WebAssemby (single-threaded)
    WebAssembly (multi-threaded)
    I also downloaded under developer tools
    MingW 11.2.0 64 bit
    CMake 3.24.2

  3. I also downloaded (apart from QT)
    ninja 1.11
    Emscripted 3.1.25
    VTK 9.2.6

    I set qmake.bat from C:\Qt\6.5.0\wasm_singlethread\bin
    cmake from C:\Qt\Tools\CMake_64
    and mingw from C:\Qt\Tools\mingw1120_64\bin
    in the environment PATH variables.

  4. So I went ahead and follow instructions based from here Qt for WebAssembly | Qt 6.5
    I ran the configure with emscripten like the one bellow,

./emsdk install 3.1.25
   
 ./emsdk activate 3.1.25
   
 configure.bat -qt-host-path C:\Qt\6.5.0\mingw_64 -no-warnings-are-errors -feature-opengles3  -device-option QT_EMSCRIPTEN_ASYNCIFY=1 -platform wasm-emscripten -prefix $PWD/qtbase

cmake –build .

All of the above is executed inside the source folder C:\Qt\6.5.0\Src
And I specify mingw_64 as the host-path as it is the ONLY one that compiles properly.

  1. Then I downloaded VTK and build like this

    emsdk activate 3.1.25

    emsdk_env.bat

    emcmake cmake . -B C:\build-vtk-wasm -GNinja -DBUILD_SHARED_LIBS:BOOL=OFF -DCMAKE_BUILD_TYPE:STRING=Release -DVTK_ENABLE_LOGGING:BOOL=OFF -DVTK_ENABLE_WRAPPING:BOOL=OFF -DVTK_MODULE_ENABLE_VTK_hdf5:STRING=NO -DVTK_MODULE_ENABLE_VTK_RenderingContextOpenGL2:STRING=DONT_WANT -DVTK_MODULE_ENABLE_VTK_RenderingLICOpenGL2:STRING=DONT_WANT -DVTK_MODULE_ENABLE_VTK_RenderingCellGrid:STRING=NO -DVTK_MODULE_ENABLE_VTK_sqlite:STRING=NO -DCMAKE_INSTALL_PREFIX=C:\vtk-install

    ninja
    ninja install

Everything builts ok without error. So I went to our project and started the build

emsdk activate 3.1.25
emsdk_env.bat
qmake.bat OurProject.pro
mingw32-make

qmake.bat is from C:\Qt\6.5.0\wasm_singlethread\bin
while mingw32-make is from C:\Qt\Tools\mingw1120_64\bin
Then I got these errors

In file included from Ui\VTKWidgets\MyQVTKOpenGLWindow.cpp:46:
In file included from ..\..\dependencies\VTK-9.2.6\include\vtk-9.2\vtk_glew.h:47:
..\..\dependencies\VTK-9.2.6\include\vtk-9.2\vtkglew/include/GL/glew.h:24591:17: error: unknown type name
      'PFNGLPOPDEBUGGROUPPROC'; did you mean 'PFNGLPOPDEBUGGROUPKHRPROC'?
GLEW_FUN_EXPORT PFNGLPOPDEBUGGROUPPROC __glewPopDebugGroup;
                ^~~~~~~~~~~~~~~~~~~~~~
                PFNGLPOPDEBUGGROUPKHRPROC
C:\Qt\6.5.0\wasm_singlethread\include\QtGui/qopengles2ext.h:155:28: note: 'PFNGLPOPDEBUGGROUPKHRPROC' declared here
typedef void (GL_APIENTRYP PFNGLPOPDEBUGGROUPKHRPROC) (void);

Im not sure what is happening here? I went to the file and PFNGLPUSHDEBUGGROUPPROC is indeed defined properly in vtk-9.2\vtkglew/include/GL/glew.h
maybe there is a conflict between OpenGL versions?
Maybe i misconfigured VTK for opengl? I am not sure what is happening here now.

Ive been stuck wth this for over 2 weeks, please help

2

Hello @cebugdev

What is the value of VTK_OPENGL_USE_GLES in your CMakeCache.txt?

3

it is set to off in VTK CMakeCache.txt

//Use the OpenGL ES API
VTK_OPENGL_USE_GLES:BOOL=OFF

Should it be ON or Off is the correct behaviour for webasm?

This is my cmake for VTK that I used

emcmake cmake . -B C:\build-vtk-wasm -GNinja -DBUILD_SHARED_LIBS:BOOL=OFF -DCMAKE_BUILD_TYPE:STRING=Release -DVTK_ENABLE_LOGGING:BOOL=OFF -DVTK_ENABLE_WRAPPING:BOOL=OFF -DVTK_MODULE_ENABLE_VTK_hdf5:STRING=NO -DVTK_MODULE_ENABLE_VTK_RenderingContextOpenGL2:STRING=DONT_WANT -DVTK_MODULE_ENABLE_VTK_RenderingLICOpenGL2:STRING=DONT_WANT -DVTK_MODULE_ENABLE_VTK_RenderingCellGrid:STRING=NO -DVTK_MODULE_ENABLE_VTK_sqlite:STRING=NO -DCMAKE_INSTALL_PREFIX=C:\vtk-install

4

It should be on. Just add -DVTK_OPENGL_USE_GLES=ON to your cmake configure arguments.

5

i think it worked, thank you, i now reach the final stages of the build which is linking.

but I am having problem, seems like freetype for VTK and QT had a clash


wasm-ld: error: duplicate symbol: ft_mem_realloc
>>> defined in ../../dependencies/VTK-9.2.6/lib\\libvtkfreetype-9.2.a(ftbase.c.o)
>>> defined in C:/Qt/6.5.0/wasm_singlethread/lib/libQt6BundledFreetype.a(ftbase.c.o)

wasm-ld: error: duplicate symbol: FT_GlyphLoader_CheckPoints
>>> defined in ../../dependencies/VTK-9.2.6/lib\\libvtkfreetype-9.2.a(ftbase.c.o)
>>> defined in C:/Qt/6.5.0/wasm_singlethread/lib/libQt6BundledFreetype.a(ftbase.c.o)

wasm-ld: error: duplicate symbol: FT_GlyphLoader_CheckSubGlyphs
>>> defined in ../../dependencies/VTK-9.2.6/lib\\libvtkfreetype-9.2.a(ftbase.c.o)
>>> defined in C:/Qt/6.5.0/wasm_singlethread/lib/libQt6BundledFreetype.a(ftbase.c.o)

How do I handle this?

6

Have you tried -DVTK_MODULE_ENABLE_VTK_RenderingFreeType:STRING=DONT_WANT? @ben.boeckel may have some ideas.

7

It looks like 9.2.6 has some unmangled symbols. Can you please test 9.3.0.rc1 so we can fix it if it needs to be?

8

Tried this still getting the errors

wasm-ld: error: duplicate symbol: FT_GlyphLoader_CreateExtra
>>> defined in ../../dependencies/VTK-9.2.6/lib\\libvtkfreetype-9.2.a(ftbase.c.o)
>>> defined in C:/Qt/6.5.0/wasm_singlethread/lib/libQt6BundledFreetype.a(ftbase.c.o)

wasm-ld: error: duplicate symbol: ft_mem_realloc
>>> defined in ../../dependencies/VTK-9.2.6/lib\\libvtkfreetype-9.2.a(ftbase.c.o)
>>> defined in C:/Qt/6.5.0/wasm_singlethread/lib/libQt6BundledFreetype.a(ftbase.c.o)

will try a different versions as suggested by Ben

Update: Tried a different version with 9.3 but same error :frowning:

9

Ok, it looks like we are missing some symbol manglings, at least on Windows. Can you please file an issue about this?

10

filed an issue in gitlab here: https://gitlab.kitware.com/vtk/vtk/-/issues/19129