Archive 17/01/2023.

Samples about calling C++ function from javascript (emscripten)

huminzheng

Hi guys!
Is there a sample about calling C++ function from javascript (emscripten)? The c++ function definied in sample application class from javascript. Thanks!

Eugene

Urho does this already, but I’m not sure how much of a sample it is.

github.com

urho3d/Urho3D/blob/master/Source/Urho3D/Graphics/OpenGL/OGLGraphics.cpp#L75

    
      
          extern "C"

          {

              GL_APICALL void GL_APIENTRY glDrawArraysInstancedANGLE (GLenum mode, GLint first, GLsizei count, GLsizei primcount);

              GL_APICALL void GL_APIENTRY glDrawElementsInstancedANGLE (GLenum mode, GLsizei count, GLenum type, const void *indices, GLsizei primcount);

              GL_APICALL void GL_APIENTRY glVertexAttribDivisorANGLE (GLuint index, GLuint divisor);

          }

          

          // Helper functions to support emscripten canvas resolution change

          static const Urho3D::Context *appContext;

          

          static void JSCanvasSize(int width, int height, bool fullscreen, float scale)

          {

              URHO3D_LOGINFOF("JSCanvasSize: width=%d height=%d fullscreen=%d ui scale=%f", width, height, fullscreen, scale);

          

              using namespace Urho3D;

          

              if (appContext)

              {

                  bool uiCursorVisible = false;

                  bool systemCursorVisible = false;

                  MouseMode mouseMode{};

github.com

urho3d/Urho3D/blob/master/bin/shell.html#L103

    
      
          
          
// Detect fullscreen change and resize canvas resolution accordingly
          function viewportResizeHandler() {
              if (document.hidden) {
                  return;
              }
          
          
    calculateCanvasSize();
              if (Module['JSCanvasSize']) {
                  if (isFullScreen()) {
                      Module.JSCanvasSize(screen.width * devicePixelRatio, screen.height * devicePixelRatio, true, devicePixelRatio);
                  } else {
                      Module.JSCanvasSize(canvasWidth, canvasHeight, false, devicePixelRatio);
                  }
              }
          }
          
          
function visibilityChanged() {
              if (document.hidden) {
                  return;
              }