--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Scene2D/ICompositor.h	Tue Jul 07 16:21:02 2020 +0200
@@ -0,0 +1,72 @@
+/**
+ * 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/>.
+ **/
+
+
+#pragma once
+
+#include "Scene2D.h"
+#include "ScenePoint2D.h"
+
+namespace OrthancStone
+{
+  class ICompositor : public boost::noncopyable
+  {
+  public:
+    virtual ~ICompositor() 
+    {
+    }
+
+    // This function can be expensive (notably in wasm)
+    virtual void RefreshCanvasSize() = 0; 
+    
+    virtual unsigned int GetCanvasWidth() const = 0;
+
+    virtual unsigned int GetCanvasHeight() const = 0;
+
+    /**
+     * WARNING: "Refresh()" must always be called with the same
+     * scene. If the scene changes, a call to "ResetScene()" must be
+     * done to reset the tracking of the revisions of the layers.
+     **/
+    virtual void Refresh(const Scene2D& scene) = 0;
+
+    virtual void ResetScene() = 0;
+
+#if ORTHANC_ENABLE_LOCALE == 1
+    virtual void SetFont(size_t index,
+                         const std::string& ttf,
+                         unsigned int fontSize,
+                         Orthanc::Encoding codepage) = 0;
+#endif
+
+    // Get the center of the given pixel, in canvas coordinates
+    ScenePoint2D GetPixelCenterCoordinates(int x, int y) const
+    {
+      return ScenePoint2D(
+        static_cast<double>(x) + 0.5 - static_cast<double>(GetCanvasWidth()) / 2.0,
+        static_cast<double>(y) + 0.5 - static_cast<double>(GetCanvasHeight()) / 2.0);
+    }
+
+    void FitContent(Scene2D& scene) const
+    {
+      scene.FitContent(GetCanvasWidth(), GetCanvasHeight());
+    }
+  };
+}