--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Samples/Sdl/TrackerSample.cpp	Thu May 09 10:41:31 2019 +0200
@@ -0,0 +1,555 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2019 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/>.
+ **/
+
+
+ // From Stone
+#include "../../Applications/Sdl/SdlOpenGLWindow.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/Scene2D.h"
+#include "../../Framework/Scene2D/ZoomSceneTracker.h"
+#include "../../Framework/StoneInitialization.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/shared_ptr.hpp>
+#include <boost/weak_ptr.hpp>
+
+#include <SDL.h>
+#include <stdio.h>
+
+
+// to be moved into Stone
+#include "../Common/MeasureTrackers.h"
+#include "../Common/MeasureCommands.h"
+
+/*
+TODO:
+
+- to decouple the trackers from the sample, we need to supply them with
+  the scene rather than the app
+
+- in order to do that, we need a GetNextFreeZIndex function (or something 
+  along those lines) in the scene object
+
+*/
+
+
+using namespace Orthanc;
+using namespace OrthancStone;
+
+namespace OrthancStone
+{
+  enum GuiTool
+  {
+    GuiTool_Rotate = 0,
+    GuiTool_Pan,
+    GuiTool_Zoom,
+    GuiTool_LineMeasure,
+    GuiTool_CircleMeasure,
+    GuiTool_AngleMeasure,
+    GuiTool_EllipseMeasure,
+    GuiTool_LAST
+  };
+
+  const char* MeasureToolToString(size_t i)
+  {
+    static const char* descs[] = {
+      "GuiTool_Rotate",
+      "GuiTool_Pan",
+      "GuiTool_Zoom",
+      "GuiTool_LineMeasure",
+      "GuiTool_CircleMeasure",
+      "GuiTool_AngleMeasure",
+      "GuiTool_EllipseMeasure",
+      "GuiTool_LAST"
+    };
+    if (i >= GuiTool_LAST)
+    {
+      throw Orthanc::OrthancException(Orthanc::ErrorCode_InternalError, "Wrong tool index");
+    }
+    return descs[i];
+  }
+}
+
+class TrackerSampleApp
+{
+public:
+  // 12 because.
+  TrackerSampleApp() : currentTool_(GuiTool_Rotate)
+  {
+    TEXTURE_2x2_1_ZINDEX  = 1;
+    TEXTURE_1x1_ZINDEX    = 2;
+    TEXTURE_2x2_2_ZINDEX  = 3;
+    LINESET_1_ZINDEX      = 4;
+    LINESET_2_ZINDEX      = 5;
+    INFOTEXT_LAYER_ZINDEX = 6;
+  }
+  void PrepareScene();
+  void Run();
+
+private:
+  Scene2D& GetScene()
+  {
+    return scene_;
+  }
+
+  void SelectNextTool()
+  {
+    currentTool_ = static_cast<GuiTool>(currentTool_ + 1);
+    if (currentTool_ == GuiTool_LAST)
+      currentTool_ = static_cast<GuiTool>(0);;
+    printf("Current tool is now: %s\n", MeasureToolToString(currentTool_));
+  }
+
+  void HandleApplicationEvent(
+    const OpenGLCompositor& compositor,
+    const SDL_Event& event,
+    std::auto_ptr<IPointerTracker>& activeTracker);
+
+  IPointerTracker* TrackerSampleApp::TrackerHitTest(const PointerEvent& e);
+
+  IPointerTracker* CreateSuitableTracker(
+    const SDL_Event& event,
+    const PointerEvent& e,
+    const OpenGLCompositor& compositor);
+  
+  void TakeScreenshot(
+    const std::string& target,
+    unsigned int canvasWidth,
+    unsigned int canvasHeight);
+
+  /**
+    This adds the command at the top of the undo stack  
+  */
+  void Commit(TrackerCommandPtr cmd);
+  void Undo();
+  void Redo();
+  
+private:
+  static const unsigned int FONT_SIZE = 32;
+
+  std::vector<TrackerCommandPtr> undoStack_;
+  
+  // we store the measure tools here so that they don't get deleted
+  std::vector<MeasureToolPtr> measureTools_;
+
+  //static const int LAYER_POSITION = 150;
+#if 0
+  int TEXTURE_2x2_1_ZINDEX = 12;
+  int TEXTURE_1x1_ZINDEX = 13;
+  int TEXTURE_2x2_2_ZINDEX = 14;
+  int LINESET_1_ZINDEX = 50;
+  int LINESET_2_ZINDEX = 100;
+  int INFOTEXT_LAYER_ZINDEX = 150;
+#else
+  int TEXTURE_2x2_1_ZINDEX;
+  int TEXTURE_1x1_ZINDEX;
+  int TEXTURE_2x2_2_ZINDEX;
+  int LINESET_1_ZINDEX;
+  int LINESET_2_ZINDEX;
+  int INFOTEXT_LAYER_ZINDEX;
+#endif
+  Scene2D scene_;
+  GuiTool currentTool_;
+};
+
+
+void TrackerSampleApp::PrepareScene()
+{
+  // 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(TEXTURE_2x2_1_ZINDEX, 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(TEXTURE_2x2_2_ZINDEX, 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(TEXTURE_1x1_ZINDEX, l.release());
+  }
+
+  // Some lines
+  {
+    std::auto_ptr<PolylineSceneLayer> layer(new PolylineSceneLayer);
+
+    layer->SetThickness(1);
+
+    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);
+
+    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);
+
+    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);
+
+    layer->SetColor(0, 255, 255);
+    scene_.SetLayer(LINESET_1_ZINDEX, layer.release());
+  }
+
+  // Some text
+  {
+    std::auto_ptr<TextSceneLayer> layer(new TextSceneLayer);
+    layer->SetText("Hello");
+    scene_.SetLayer(LINESET_2_ZINDEX, layer.release());
+  }
+}
+
+
+void TrackerSampleApp::TakeScreenshot(const std::string& target,
+  unsigned int canvasWidth,
+  unsigned int canvasHeight)
+{
+  // 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);
+}
+
+
+IPointerTracker* TrackerSampleApp::TrackerHitTest(const PointerEvent& e)
+{
+  // std::vector<MeasureToolPtr> measureTools_;
+  return nullptr;
+}
+
+IPointerTracker* TrackerSampleApp::CreateSuitableTracker(
+  const SDL_Event& event, 
+  const PointerEvent& e, 
+  const OpenGLCompositor& compositor)
+{
+  switch (event.button.button)
+  {
+  case SDL_BUTTON_MIDDLE:
+    return new PanSceneTracker(scene_, e);
+
+  case SDL_BUTTON_RIGHT:
+    return new ZoomSceneTracker(
+      scene_, e, compositor.GetCanvasHeight());
+
+  case SDL_BUTTON_LEFT:
+  {
+    // TODO: we need to iterate on the set of measuring tool and perform
+    // a hit test to check if a tracker needs to be created for edition.
+    // Otherwise, depending upon the active tool, we might want to create
+    // a "measuring tool creation" tracker
+
+    // TODO: if there are conflicts, we should prefer a tracker that 
+    // pertains to the type of measuring tool currently selected (TBD?)
+    IPointerTracker* hitTestTracker = TrackerHitTest(e);
+    
+    if (hitTestTracker != NULL)
+    {
+      return hitTestTracker;
+    }
+    else
+    { 
+      switch (currentTool_)
+      {
+      case GuiTool_Rotate:
+        return new RotateSceneTracker(scene_, e);
+      case GuiTool_LineMeasure:
+        return new CreateLineMeasureTracker(
+          scene_, undoStack_, measureTools_, e);
+        //case GuiTool_AngleMeasure:
+        //  return new AngleMeasureTracker(scene_, measureTools_, undoStack_, e);
+        //case GuiTool_CircleMeasure:
+        //  return new CircleMeasureTracker(scene_, measureTools_, undoStack_, e);
+        //case GuiTool_EllipseMeasure:
+        //  return new EllipseMeasureTracker(scene_, measureTools_, undoStack_, e);
+      default:
+        throw OrthancException(ErrorCode_InternalError, "Wrong tool!");
+      }
+    }
+  }
+  default:
+    return NULL;
+  }
+}
+
+void TrackerSampleApp::HandleApplicationEvent(
+  const OpenGLCompositor& compositor,
+  const SDL_Event& event,
+  std::auto_ptr<IPointerTracker>& activeTracker)
+{
+  if (event.type == SDL_MOUSEMOTION)
+  {
+    int scancodeCount = 0;
+    const uint8_t* keyboardState = SDL_GetKeyboardState(&scancodeCount);
+
+    if (activeTracker.get() == NULL &&
+      SDL_SCANCODE_LCTRL < scancodeCount &&
+      keyboardState[SDL_SCANCODE_LCTRL])
+    {
+      // The "left-ctrl" key is down, while no tracker is present
+
+      PointerEvent e;
+      e.AddPosition(compositor.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());
+
+      if (scene_.HasLayer(INFOTEXT_LAYER_ZINDEX))
+      {
+        TextSceneLayer& layer =
+          dynamic_cast<TextSceneLayer&>(scene_.GetLayer(INFOTEXT_LAYER_ZINDEX));
+        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(INFOTEXT_LAYER_ZINDEX, layer.release());
+      }
+    }
+    else
+    {
+      scene_.DeleteLayer(INFOTEXT_LAYER_ZINDEX);
+    }
+  }
+  else if (event.type == SDL_MOUSEBUTTONDOWN)
+  {
+    PointerEvent e;
+    e.AddPosition(compositor.GetPixelCenterCoordinates(event.button.x, event.button.y));
+
+    activeTracker.reset(CreateSuitableTracker(event, e, compositor));
+  }
+  else if (event.type == SDL_KEYDOWN &&
+    event.key.repeat == 0 /* Ignore key bounce */)
+  {
+    switch (event.key.keysym.sym)
+    {
+    case SDLK_s:
+      scene_.FitContent(compositor.GetCanvasWidth(),
+        compositor.GetCanvasHeight());
+      break;
+
+    case SDLK_c:
+      TakeScreenshot(
+        "screenshot.png",
+        compositor.GetCanvasWidth(),
+        compositor.GetCanvasHeight());
+      break;
+
+    default:
+      break;
+    }
+  }
+}
+
+
+static void GLAPIENTRY
+OpenGLMessageCallback(GLenum source,
+  GLenum type,
+  GLuint id,
+  GLenum severity,
+  GLsizei length,
+  const GLchar* message,
+  const void* userParam)
+{
+  if (severity != GL_DEBUG_SEVERITY_NOTIFICATION)
+  {
+    fprintf(stderr, "GL CALLBACK: %s type = 0x%x, severity = 0x%x, message = %s\n",
+      (type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : ""),
+      type, severity, message);
+  }
+}
+
+bool g_stopApplication = false;
+
+void TrackerSampleApp::Run()
+{
+  SdlOpenGLWindow window("Hello", 1024, 768);
+
+  scene_.FitContent(window.GetCanvasWidth(), window.GetCanvasHeight());
+
+  glEnable(GL_DEBUG_OUTPUT);
+  glDebugMessageCallback(OpenGLMessageCallback, 0);
+
+  OpenGLCompositor compositor(window, scene_);
+  compositor.SetFont(0, Orthanc::EmbeddedResources::UBUNTU_FONT,
+    FONT_SIZE, Orthanc::Encoding_Latin1);
+
+  // this will either be empty or contain the current tracker, if any
+  std::auto_ptr<IPointerTracker>  tracker;
+
+ 
+  while (!g_stopApplication)
+  {
+    compositor.Refresh();
+
+    SDL_Event event;
+    while (!g_stopApplication && SDL_PollEvent(&event))
+    {
+      if (event.type == SDL_QUIT)
+      {
+        g_stopApplication = true;
+        break;
+      }
+      else if (event.type == SDL_MOUSEMOTION)
+      {
+        if (tracker.get() != NULL)
+        {
+          PointerEvent e;
+          e.AddPosition(compositor.GetPixelCenterCoordinates(event.button.x, event.button.y));
+          LOG(TRACE) << "event.button.x = " << event.button.x << "     " <<
+            "event.button.y = " << event.button.y;
+          tracker->Update(e);
+        }
+      }
+      else if (event.type == SDL_MOUSEBUTTONUP)
+      {
+        if (tracker.get() != NULL)
+        {
+          tracker->Release();
+          tracker.reset(NULL);
+        }
+      }
+      else if (event.type == SDL_WINDOWEVENT &&
+        event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)
+      {
+        tracker.reset(NULL);
+        compositor.UpdateSize();
+      }
+      else if (event.type == SDL_KEYDOWN &&
+        event.key.repeat == 0 /* Ignore key bounce */)
+      {
+        switch (event.key.keysym.sym)
+        {
+        case SDLK_f:
+          window.GetWindow().ToggleMaximize();
+          break;
+
+        case SDLK_q:
+          g_stopApplication = true;
+          break;
+
+        case SDLK_t:
+          SelectNextTool();
+          break;
+
+        default:
+          break;
+        }
+      }
+      HandleApplicationEvent(compositor, event, tracker);
+    }
+    SDL_Delay(1);
+  }
+}
+
+
+/**
+ * IMPORTANT: The full arguments to "main()" are needed for SDL on
+ * Windows. Otherwise, one gets the linking error "undefined reference
+ * to `SDL_main'". https://wiki.libsdl.org/FAQWindows
+ **/
+int main(int argc, char* argv[])
+{
+  StoneInitialize();
+  Orthanc::Logging::EnableInfoLevel(true);
+
+  try
+  {
+    TrackerSampleApp app;
+    app.PrepareScene();
+    app.Run();
+  }
+  catch (Orthanc::OrthancException& e)
+  {
+    LOG(ERROR) << "EXCEPTION: " << e.What();
+  }
+
+  StoneFinalize();
+
+  return 0;
+}