--- a/Samples/WebAssembly/RtViewer/RtViewerWasm.cpp	Tue Apr 28 13:52:21 2020 +0200
+++ b/Samples/WebAssembly/RtViewer/RtViewerWasm.cpp	Wed Apr 29 15:54:18 2020 +0200
@@ -0,0 +1,170 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2020 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+#include "RtViewer.h"
+#include "SampleHelpers.h"
+
+// Stone of Orthanc includes
+#include <Framework/Loaders/WebAssemblyLoadersContext.h>
+//#include <Framework/OpenGL/WebAssemblyOpenGLContext.h>
+#include <Framework/Viewport/WebGLViewport.h>
+#include <Framework/StoneException.h>
+#include <Framework/StoneInitialization.h>
+
+#include <Framework/Loaders/WebAssemblyLoadersContext.h>
+
+#include <Framework/StoneException.h>
+#include <Framework/StoneInitialization.h>
+
+#include <Core/Toolbox.h>
+
+#include <boost/program_options.hpp>
+#include <boost/shared_ptr.hpp>
+// #include <boost/pointer_cast.hpp> this include might be necessary in more recent boost versions
+
+#include <emscripten.h>
+#include <emscripten/html5.h>
+
+
+#define DISPATCH_JAVASCRIPT_EVENT(name)                         \
+  EM_ASM(                                                       \
+    const customEvent = document.createEvent("CustomEvent");    \
+    customEvent.initCustomEvent(name, false, false, undefined); \
+    window.dispatchEvent(customEvent);                          \
+    );
+
+#define EXTERN_CATCH_EXCEPTIONS                         \
+  catch (Orthanc::OrthancException& e)                  \
+  {                                                     \
+    LOG(ERROR) << "OrthancException: " << e.What();     \
+    DISPATCH_JAVASCRIPT_EVENT("StoneException");        \
+  }                                                     \
+  catch (OrthancStone::StoneException& e)               \
+  {                                                     \
+    LOG(ERROR) << "StoneException: " << e.What();       \
+    DISPATCH_JAVASCRIPT_EVENT("StoneException");        \
+  }                                                     \
+  catch (std::exception& e)                             \
+  {                                                     \
+    LOG(ERROR) << "Runtime error: " << e.what();        \
+    DISPATCH_JAVASCRIPT_EVENT("StoneException");        \
+  }                                                     \
+  catch (...)                                           \
+  {                                                     \
+    LOG(ERROR) << "Native exception";                   \
+    DISPATCH_JAVASCRIPT_EVENT("StoneException");        \
+  }
+
+namespace OrthancStone
+{
+  void RtViewerApp::CreateViewport()
+  {
+    viewport_ = WebGLViewport::Create("mycanvas1");
+  }
+
+  void RtViewerApp::TakeScreenshot(const std::string& target,
+                                   unsigned int canvasWidth,
+                                   unsigned int canvasHeight)
+  {
+    throw Orthanc::OrthancException(Orthanc::ErrorCode_NotImplemented);
+  }
+
+
+  void RtViewerApp::RunWasm()
+  {
+    {
+      std::unique_ptr<IViewport::ILock> lock(viewport_->Lock());
+      ViewportController& controller = lock->GetController();
+      Scene2D& scene = controller.GetScene();
+      ICompositor& compositor = lock->GetCompositor();
+
+      controller.FitContent(compositor.GetCanvasWidth(), compositor.GetCanvasHeight());
+
+      compositor.SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT,
+                         FONT_SIZE_0, Orthanc::Encoding_Latin1);
+      compositor.SetFont(1, Orthanc::EmbeddedResources::UBUNTU_FONT,
+                         FONT_SIZE_1, Orthanc::Encoding_Latin1);
+    }
+
+    loadersContext_.reset(new OrthancStone::WebAssemblyLoadersContext(1, 4, 1));
+
+    // we are in WASM --> downcast to concrete type
+    boost::shared_ptr<WebAssemblyLoadersContext> loadersContext = 
+      boost::dynamic_pointer_cast<WebAssemblyLoadersContext>(loadersContext_);
+
+    if (HasArgument("orthanc"))
+      loadersContext->SetLocalOrthanc(GetArgument("orthanc"));
+    else 
+      loadersContext->SetLocalOrthanc("..");
+
+    loadersContext->SetDicomCacheSize(128 * 1024 * 1024);  // 128MB
+
+    PrepareLoadersAndSlicers();
+
+    DefaultViewportInteractor interactor;
+  }
+}
+
+extern "C"
+{
+  boost::shared_ptr<OrthancStone::RtViewerApp> g_app;
+
+  int main(int argc, char const *argv[]) 
+  {
+    try
+    {
+      OrthancStone::StoneInitialize();
+      Orthanc::Logging::Initialize();
+      Orthanc::Logging::EnableTraceLevel(true);
+
+      LOG(WARNING) << "Initializing native Stone";
+
+      LOG(WARNING) << "Compiled with Emscripten " << __EMSCRIPTEN_major__
+                   << "." << __EMSCRIPTEN_minor__
+                   << "." << __EMSCRIPTEN_tiny__;
+
+      LOG(INFO) << "Endianness: " << Orthanc::EnumerationToString(Orthanc::Toolbox::DetectEndianness());
+
+      g_app = OrthancStone::RtViewerApp::Create();
+  
+      DISPATCH_JAVASCRIPT_EVENT("WasmModuleInitialized");
+    }
+    EXTERN_CATCH_EXCEPTIONS;
+  }
+
+  EMSCRIPTEN_KEEPALIVE
+  void Initialize(const char* canvasId)
+  {
+    try
+    {
+      g_app->RunWasm();
+    }
+    EXTERN_CATCH_EXCEPTIONS;
+  }
+
+  EMSCRIPTEN_KEEPALIVE
+  void SetArgument(const char* key, const char* value)
+  {
+    // This is called for each GET argument (cf. "app.js")
+    LOG(INFO) << "Received GET argument: [" << key << "] = [" << value << "]";
+    g_app->SetArgument(key, value);
+  }
+
+}