--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Applications/Samples/WebAssembly/RtViewer/RtViewerWasm.cpp	Tue Aug 11 13:24:38 2020 +0200
@@ -0,0 +1,196 @@
+/**
+ * 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 "../../Common/RtViewerApp.h"
+#include "../../Common/RtViewerView.h"
+#include "../../Common/SampleHelpers.h"
+
+// Stone of Orthanc includes
+#include "../../../Sources/Loaders/WebAssemblyLoadersContext.h"
+#include "../../../Sources/StoneException.h"
+#include "../../../Sources/StoneInitialization.h"
+#include "../../../Sources/Viewport/WebGLViewport.h"
+//#include "../../../Sources/OpenGL/WebAssemblyOpenGLContext.h"
+
+#include <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
+{
+  //   typedef EM_BOOL (*OnMouseWheelFunc)(int eventType, const EmscriptenWheelEvent* wheelEvent, void* userData);
+
+  EM_BOOL RtViewerView_Scroll(int eventType, 
+                              const EmscriptenWheelEvent* wheelEvent, 
+                              void* userData)
+  {
+    RtViewerView* that = reinterpret_cast<RtViewerView*>(userData);
+
+    int delta = 0;
+    if (wheelEvent->deltaY < 0)
+      delta = -1;
+    if (wheelEvent->deltaY > 0)
+      delta = 1;
+
+    that->Scroll(delta);
+
+    return 1;
+  }
+  
+  boost::shared_ptr<IViewport> RtViewerView::CreateViewport(
+    const std::string& canvasId)
+  {
+    boost::shared_ptr<IViewport> viewport = WebGLViewport::Create(canvasId);
+
+    void* userData = reinterpret_cast<void*>(this);
+
+    // manually add the mouse wheel handler
+
+    std::string selector = "#" + canvasId;
+
+    emscripten_set_wheel_callback_on_thread(
+      selector.c_str(),
+      userData,
+      false,
+      &RtViewerView_Scroll,
+      EM_CALLBACK_THREAD_CONTEXT_CALLING_THREAD);
+
+    return viewport;
+  }
+
+  void RtViewerView::TakeScreenshot(const std::string& target,
+                                   unsigned int canvasWidth,
+                                   unsigned int canvasHeight)
+  {
+    throw Orthanc::OrthancException(Orthanc::ErrorCode_NotImplemented);
+  }
+
+
+  void RtViewerApp::RunWasm()
+  {
+    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
+
+    CreateLoaders();
+    
+    CreateView("RtViewer_Axial", VolumeProjection_Axial);
+    CreateView("RtViewer_Coronal", VolumeProjection_Coronal);
+    CreateView("RtViewer_Sagittal", VolumeProjection_Sagittal);
+
+    for (size_t i = 0; i < views_.size(); ++i)
+    {
+      views_[i]->PrepareViewport();
+    }
+
+    StartLoaders();
+  }
+}
+
+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);
+  }
+
+}