--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Applications/Platforms/WebAssembly/WebGLViewport.cpp	Fri Oct 23 13:15:03 2020 +0200
@@ -0,0 +1,86 @@
+/**
+ * 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 "WebGLViewport.h"
+
+#include "../../../OrthancStone/Sources/StoneException.h"
+#include "../../../OrthancStone/Sources/Scene2D/OpenGLCompositor.h"
+#include "../../../OrthancStone/Sources/Scene2DViewport/ViewportController.h"
+
+namespace OrthancStone
+{
+  void WebGLViewport::Paint(ICompositor& compositor,
+                            ViewportController& controller)
+  {
+    try
+    {
+      compositor.Refresh(controller.GetScene());
+
+      /**
+       * No need to manually swap the buffer: "Rendered WebGL content
+       * is implicitly presented (displayed to the user) on the canvas
+       * when the event handler that renders with WebGL returns back
+       * to the browser event loop."
+       * https://emscripten.org/docs/api_reference/html5.h.html#webgl-context
+       *
+       * Could call "emscripten_webgl_commit_frame()" if
+       * "explicitSwapControl" option were set to "true".
+       **/
+    }
+    catch (const StoneException& e)
+    {
+      // Ignore problems about the loss of the WebGL context (edge case)
+      if (e.GetErrorCode() == ErrorCode_WebGLContextLost)
+      {
+        return;
+      }
+      else
+      {
+        throw;
+      }
+    }
+  }
+    
+
+  WebGLViewport::WebGLViewport(const std::string& canvasId, bool enableEmscriptenMouseEvents) :
+    WebAssemblyViewport(canvasId,enableEmscriptenMouseEvents),
+    context_(GetCanvasCssSelector())
+  {
+    AcquireCompositor(new OpenGLCompositor(context_));
+  }
+
+  boost::shared_ptr<WebGLViewport> WebGLViewport::Create(
+    const std::string& canvasId, bool enableEmscriptenMouseEvents)
+  {
+    boost::shared_ptr<WebGLViewport> that = boost::shared_ptr<WebGLViewport>(
+        new WebGLViewport(canvasId, enableEmscriptenMouseEvents));
+    
+    that->WebAssemblyViewport::PostConstructor();
+    return that;
+  }
+
+  WebGLViewport::~WebGLViewport()
+  {
+    // Make sure to delete the compositor before its parent "context_" gets
+    // deleted
+    ClearCompositor();
+  }
+}