--- a/Samples/Sdl/BasicScene.cpp	Fri Jul 12 14:57:48 2019 +0200
+++ b/Samples/Sdl/BasicScene.cpp	Tue Jul 16 12:37:29 2019 +0200
@@ -20,71 +20,243 @@
 
 
 // From Stone
-#include "../../Applications/Sdl/SdlOpenGLWindow.h"
+#include "../../Framework/Viewport/SdlViewport.h"
+#include "../../Framework/Scene2D/CairoCompositor.h"
+#include "../../Framework/Scene2D/ColorTextureSceneLayer.h"
 #include "../../Framework/Scene2D/OpenGLCompositor.h"
+#include "../../Framework/Scene2D/PanSceneTracker.h"
+#include "../../Framework/Scene2D/RotateSceneTracker.h"
+#include "../../Framework/Scene2D/ZoomSceneTracker.h"
+#include "../../Framework/Scene2DViewport/ViewportController.h"
 #include "../../Framework/Scene2DViewport/UndoStack.h"
+
 #include "../../Framework/StoneInitialization.h"
 #include "../../Framework/Messages/MessageBroker.h"
 
 // From Orthanc framework
 #include <Core/Logging.h>
 #include <Core/OrthancException.h>
+#include <Core/Images/Image.h>
+#include <Core/Images/ImageProcessing.h>
+#include <Core/Images/PngWriter.h>
 
 #include <boost/make_shared.hpp>
-#include <boost/ref.hpp>
 
 #include <SDL.h>
 #include <stdio.h>
 
-
-#include "../Shared/SharedBasicScene.h"
-
-using namespace OrthancStone;
+static const unsigned int FONT_SIZE = 32;
+static const int LAYER_POSITION = 150;
 
-boost::shared_ptr<BasicScene2DInteractor> interactor;
 
-void HandleApplicationEvent(boost::shared_ptr<OrthancStone::ViewportController> controller,
-                            const OrthancStone::OpenGLCompositor& compositor,
-                            const SDL_Event& event)
+void PrepareScene(OrthancStone::Scene2D& scene)
 {
   using namespace OrthancStone;
-  Scene2D& scene(*controller->GetScene());
-  if (event.type == SDL_MOUSEBUTTONDOWN || event.type == SDL_MOUSEBUTTONUP || event.type == SDL_MOUSEMOTION)
+
+  // Texture of 2x2 size
+  {
+    Orthanc::Image i(Orthanc::PixelFormat_RGB24, 2, 2, false);
+    
+    uint8_t *p = reinterpret_cast<uint8_t*>(i.GetRow(0));
+    p[0] = 255;
+    p[1] = 0;
+    p[2] = 0;
+
+    p[3] = 0;
+    p[4] = 255;
+    p[5] = 0;
+
+    p = reinterpret_cast<uint8_t*>(i.GetRow(1));
+    p[0] = 0;
+    p[1] = 0;
+    p[2] = 255;
+
+    p[3] = 255;
+    p[4] = 0;
+    p[5] = 0;
+
+    scene.SetLayer(12, new ColorTextureSceneLayer(i));
+
+    std::auto_ptr<ColorTextureSceneLayer> l(new ColorTextureSceneLayer(i));
+    l->SetOrigin(-3, 2);
+    l->SetPixelSpacing(1.5, 1);
+    l->SetAngle(20.0 / 180.0 * M_PI);
+    scene.SetLayer(14, l.release());
+  }
+
+  // Texture of 1x1 size
+  {
+    Orthanc::Image i(Orthanc::PixelFormat_RGB24, 1, 1, false);
+    
+    uint8_t *p = reinterpret_cast<uint8_t*>(i.GetRow(0));
+    p[0] = 255;
+    p[1] = 0;
+    p[2] = 0;
+
+    std::auto_ptr<ColorTextureSceneLayer> l(new ColorTextureSceneLayer(i));
+    l->SetOrigin(-2, 1);
+    l->SetAngle(20.0 / 180.0 * M_PI);
+    scene.SetLayer(13, l.release());
+  }
+
+  // Some lines
   {
-    // TODO: this code is copy/pasted from GuiAdapter::Run() -> find the right place
+    std::auto_ptr<PolylineSceneLayer> layer(new PolylineSceneLayer);
+
+    layer->SetThickness(10);
+
+    PolylineSceneLayer::Chain chain;
+    chain.push_back(ScenePoint2D(0 - 0.5, 0 - 0.5));
+    chain.push_back(ScenePoint2D(0 - 0.5, 2 - 0.5));
+    chain.push_back(ScenePoint2D(2 - 0.5, 2 - 0.5));
+    chain.push_back(ScenePoint2D(2 - 0.5, 0 - 0.5));
+    layer->AddChain(chain, true, 255, 0, 0);
+
+    chain.clear();
+    chain.push_back(ScenePoint2D(-5, -5));
+    chain.push_back(ScenePoint2D(5, -5));
+    chain.push_back(ScenePoint2D(5, 5));
+    chain.push_back(ScenePoint2D(-5, 5));
+    layer->AddChain(chain, true, 0, 255, 0);
+
+    double dy = 1.01;
+    chain.clear();
+    chain.push_back(ScenePoint2D(-4, -4));
+    chain.push_back(ScenePoint2D(4, -4 + dy));
+    chain.push_back(ScenePoint2D(-4, -4 + 2.0 * dy));
+    chain.push_back(ScenePoint2D(4, 2));
+    layer->AddChain(chain, false, 0, 0, 255);
+
+    scene.SetLayer(50, layer.release());
+  }
+
+  // Some text
+  {
+    std::auto_ptr<TextSceneLayer> layer(new TextSceneLayer);
+    layer->SetText("Hello");
+    scene.SetLayer(100, layer.release());
+  }
+}
+
+
+void TakeScreenshot(const std::string& target,
+                    const OrthancStone::Scene2D& scene,
+                    unsigned int canvasWidth,
+                    unsigned int canvasHeight)
+{
+  using namespace OrthancStone;
+  // Take a screenshot, then save it as PNG file
+  CairoCompositor compositor(scene, canvasWidth, canvasHeight);
+  compositor.SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT, FONT_SIZE, Orthanc::Encoding_Latin1);
+  compositor.Refresh();
+
+  Orthanc::ImageAccessor canvas;
+  compositor.GetCanvas().GetReadOnlyAccessor(canvas);
+
+  Orthanc::Image png(Orthanc::PixelFormat_RGB24, canvas.GetWidth(), canvas.GetHeight(), false);
+  Orthanc::ImageProcessing::Convert(png, canvas);
+        
+  Orthanc::PngWriter writer;
+  writer.WriteToFile(target, png);
+}
+
+
+void HandleApplicationEvent(const SDL_Event& event,
+                            boost::shared_ptr<OrthancStone::ViewportController>& controller,
+                            boost::shared_ptr<OrthancStone::IFlexiblePointerTracker>& activeTracker)
+{
+  using namespace OrthancStone;
+
+  Scene2D& scene = controller->GetScene();
+  IViewport& viewport = controller->GetViewport();
+
+  if (event.type == SDL_MOUSEMOTION)
+  {
     int scancodeCount = 0;
     const uint8_t* keyboardState = SDL_GetKeyboardState(&scancodeCount);
-    bool ctrlPressed(false);
-    bool shiftPressed(false);
-    bool altPressed(false);
+
+    if (activeTracker.get() == NULL &&
+        SDL_SCANCODE_LCTRL < scancodeCount &&
+        keyboardState[SDL_SCANCODE_LCTRL])
+    {
+      // The "left-ctrl" key is down, while no tracker is present
 
-    if (SDL_SCANCODE_LCTRL < scancodeCount && keyboardState[SDL_SCANCODE_LCTRL])
-      ctrlPressed = true;
-    if (SDL_SCANCODE_RCTRL < scancodeCount && keyboardState[SDL_SCANCODE_RCTRL])
-      ctrlPressed = true;
-    if (SDL_SCANCODE_LSHIFT < scancodeCount && keyboardState[SDL_SCANCODE_LSHIFT])
-      shiftPressed = true;
-    if (SDL_SCANCODE_RSHIFT < scancodeCount && keyboardState[SDL_SCANCODE_RSHIFT])
-      shiftPressed = true;
-    if (SDL_SCANCODE_LALT < scancodeCount && keyboardState[SDL_SCANCODE_LALT])
-      altPressed = true;
+      PointerEvent e;
+      e.AddPosition(viewport.GetPixelCenterCoordinates(event.button.x, event.button.y));
+
+      ScenePoint2D p = e.GetMainPosition().Apply(scene.GetCanvasToSceneTransform());
+
+      char buf[64];
+      sprintf(buf, "(%0.02f,%0.02f)", p.GetX(), p.GetY());
 
-    GuiAdapterMouseEvent guiEvent;
-    ConvertFromPlatform(guiEvent, ctrlPressed, shiftPressed, altPressed, event);
-    PointerEvent pointerEvent;
-    pointerEvent.AddPosition(compositor.GetPixelCenterCoordinates(event.button.x, event.button.y));
-
-    interactor->OnMouseEvent(guiEvent, pointerEvent);
-    return;
+      if (scene.HasLayer(LAYER_POSITION))
+      {
+        TextSceneLayer& layer =
+          dynamic_cast<TextSceneLayer&>(scene.GetLayer(LAYER_POSITION));
+        layer.SetText(buf);
+        layer.SetPosition(p.GetX(), p.GetY());
+      }
+      else
+      {
+        std::auto_ptr<TextSceneLayer> 
+          layer(new TextSceneLayer);
+        layer->SetColor(0, 255, 0);
+        layer->SetText(buf);
+        layer->SetBorder(20);
+        layer->SetAnchor(BitmapAnchor_BottomCenter);
+        layer->SetPosition(p.GetX(), p.GetY());
+        scene.SetLayer(LAYER_POSITION, layer.release());
+      }
+    }
+    else
+    {
+      scene.DeleteLayer(LAYER_POSITION);
+    }
   }
-  else if ((event.type == SDL_KEYDOWN || event.type == SDL_KEYUP) && event.key.repeat == 0  /* Ignore key bounce */)
+  else if (event.type == SDL_MOUSEBUTTONDOWN)
   {
-    GuiAdapterKeyboardEvent guiEvent;
-    ConvertFromPlatform(guiEvent, event);
+    PointerEvent e;
+    e.AddPosition(viewport.GetPixelCenterCoordinates(event.button.x, event.button.y));
+
+    switch (event.button.button)
+    {
+      case SDL_BUTTON_MIDDLE:
+        activeTracker = boost::make_shared<PanSceneTracker>(controller, e);
+        break;
+
+      case SDL_BUTTON_RIGHT:
+        activeTracker = boost::make_shared<ZoomSceneTracker>
+          (controller, e, viewport.GetCanvasHeight());
+        break;
+
+      case SDL_BUTTON_LEFT:
+        activeTracker = boost::make_shared<RotateSceneTracker>(controller, e);
+        break;
 
-    interactor->OnKeyboardEvent(guiEvent);
+      default:
+        break;
+    }
   }
-
+  else if (event.type == SDL_KEYDOWN &&
+           event.key.repeat == 0 /* Ignore key bounce */)
+  {
+    switch (event.key.keysym.sym)
+    {
+      case SDLK_s:
+        controller->FitContent(viewport.GetCanvasWidth(), 
+                               viewport.GetCanvasHeight());
+        break;
+              
+      case SDLK_c:
+        TakeScreenshot("screenshot.png", scene, 
+                       viewport.GetCanvasWidth(), 
+                       viewport.GetCanvasHeight());
+        break;
+              
+      default:
+        break;
+    }
+  }
 }
 
 
@@ -106,24 +278,24 @@
 }
 
 
-void Run(boost::shared_ptr<OrthancStone::ViewportController> controller)
+void Run(OrthancStone::MessageBroker& broker,
+         OrthancStone::SdlViewport& viewport)
 {
-  SdlOpenGLWindow window("Hello", 1024, 768);
-
-  controller->FitContent(window.GetCanvasWidth(), window.GetCanvasHeight());
+  using namespace OrthancStone;
+  
+  boost::shared_ptr<ViewportController> controller(
+    new ViewportController(boost::make_shared<UndoStack>(), broker, viewport));
   
   glEnable(GL_DEBUG_OUTPUT);
   glDebugMessageCallback(OpenGLMessageCallback, 0);
 
-  boost::shared_ptr<OpenGLCompositor> compositor(new OpenGLCompositor(window, *controller->GetScene()));
-  compositor->SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT,
-                     BASIC_SCENE_FONT_SIZE, Orthanc::Encoding_Latin1);
-  interactor->SetCompositor(compositor);
+  boost::shared_ptr<IFlexiblePointerTracker> tracker;
 
+  bool firstShown = true;
   bool stop = false;
   while (!stop)
   {
-    compositor->Refresh();
+    viewport.Refresh();
 
     SDL_Event event;
     while (!stop &&
@@ -134,10 +306,49 @@
         stop = true;
         break;
       }
-      else if (event.type == SDL_WINDOWEVENT &&
-               event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+      else if (event.type == SDL_MOUSEMOTION)
+      {
+        if (tracker)
+        {
+          PointerEvent e;
+          e.AddPosition(viewport.GetPixelCenterCoordinates(
+            event.button.x, event.button.y));
+          tracker->PointerMove(e);
+        }
+      }
+      else if (event.type == SDL_MOUSEBUTTONUP)
       {
-        compositor->UpdateSize();
+        if (tracker)
+        {
+          PointerEvent e;
+          e.AddPosition(viewport.GetPixelCenterCoordinates(
+            event.button.x, event.button.y));
+          tracker->PointerUp(e);
+          if(!tracker->IsAlive())
+            tracker.reset();
+        }
+      }
+      else if (event.type == SDL_WINDOWEVENT)
+      {
+        switch (event.window.event)
+        {
+          case SDL_WINDOWEVENT_SIZE_CHANGED:
+            tracker.reset();
+            break;
+
+          case SDL_WINDOWEVENT_SHOWN:
+            if (firstShown)
+            {
+              // Once the window is first shown, fit the content to its size
+              controller->FitContent(viewport.GetCanvasWidth(), viewport.GetCanvasHeight());
+              firstShown = false;
+            }
+            
+            break;
+
+          default:
+            break;
+        }
       }
       else if (event.type == SDL_KEYDOWN &&
                event.key.repeat == 0 /* Ignore key bounce */)
@@ -145,7 +356,7 @@
         switch (event.key.keysym.sym)
         {
           case SDLK_f:
-            window.GetWindow().ToggleMaximize();
+            viewport.GetContext().GetWindow().ToggleMaximize();
             break;
               
           case SDLK_q:
@@ -157,12 +368,11 @@
         }
       }
       
-      HandleApplicationEvent(controller, *compositor, event);
+      HandleApplicationEvent(event, controller, tracker);
     }
 
     SDL_Delay(1);
   }
-  interactor.reset();
 }
 
 
@@ -175,26 +385,26 @@
  **/
 int main(int argc, char* argv[])
 {
-  using namespace OrthancStone;
-  StoneInitialize();
+  OrthancStone::StoneInitialize();
   Orthanc::Logging::EnableInfoLevel(true);
 
   try
   {
-    MessageBroker broker;
-    boost::shared_ptr<UndoStack> undoStack(new UndoStack);
-    boost::shared_ptr<ViewportController> controller = boost::make_shared<ViewportController>(
-      undoStack, boost::ref(broker));
-    interactor.reset(new BasicScene2DInteractor(controller));
-    PrepareScene(controller);
-    Run(controller);
+    OrthancStone::SdlViewport viewport("Hello", 1024, 768);
+    PrepareScene(viewport.GetScene());
+
+    viewport.GetCompositor().SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT, 
+                                     FONT_SIZE, Orthanc::Encoding_Latin1);
+    
+    OrthancStone::MessageBroker broker;
+    Run(broker, viewport);
   }
   catch (Orthanc::OrthancException& e)
   {
     LOG(ERROR) << "EXCEPTION: " << e.What();
   }
 
-  StoneFinalize();
+  OrthancStone::StoneFinalize();
 
   return 0;
 }