Here is a simple example about how to pass information by json from js to wasm (C++ generated). We will pass enum value with json in the following project. C++ JS: If you want to write a whole CPlusPlus + js web app, you can refer to our old project: Read more…
The post introduces two topics. My explore was based on the old project from What will happen if we pass wrong vtkRenderer object for vtkPicker::Pick?. Just see the important logics about our issue at the following diff file. vector.diff: Rememder use register_vector to export vector<int> and use it in js when Read more…
There is Aborted crash on browser when I resize window. My web app is based on VTK wasm. Check uiEventHandlerFunc in Test.js: Then we can read /emsdk/upstream/emscripten/src/library_html5.js and find registerUiEventCallback and uiEventHandlerFunc on the file. There is checkInt32(e.detail) in registerUiEventCallback in exported js file Test.js which was generated from emsdk Read more…
I encountered a crash bug on browser in a destructor of class. I found the definition of emscripten_set_wheel_callback_on_thread in `/emsdk/upstream/emscripten/src/library_html5.js`. It doesn’t check target before using it. It’s bad code. So I checked the version of emsdk: Then I upgraded emsdk to 3.1.51: Had been new version: There is a Read more…
WebAssembly’s std::thread underlying Web Workers relies on the browser, which has a strict limit on the number of Workers that can be active at the same time (usually the number of physical CPU cores, such as 4-8). Why does a two-tier loop (say 10×10) create threads that consume more resources Read more…
Here is an example about how to write stl file to wasm virtual memory and make wasm module read it. We need to add write file logic in onRuntimeInitialized for wasm module. index.html: C++ code for wasm module: binding.cpp Worker.cpp All code has been upload to GitHub: https://github.com/theArcticOcean/webLib/tree/main/threadTest
Configure the SharedArrayBuffer response header in the http.server module of the Python standard library to enable the server to support a web multithreading environment. Let’s support SharedArrayBuffer on web browser. SharedArrayBuffer is a JavaScript object that allows multiple WebWorker threads to share the same memory space. This means that different Read more…
I found an interesting issue about vtkSDL2OpenGLRenderWindow::SetSize when changed canvas for VTK WASM 3D window.The related post on the website is Change Canvas For VTK WASM Project. The interface SetSize can work if it was used before m_RenderWindowInteractor->SetRenderWindow( newWin );.It means the 3D window will become smaller or bigger than the outer shell. The red object Read more…
There are some errors and warnings after I changed canvas for VTK wasm. The related post: https://www.weiy.city/2023/11/change-canvas-for-vtk-wasm-project/ We need to free up graphics resources with the old window before we render again. worker.cpp: