/**
 * Stone of Orthanc
 * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
 * Department, University Hospital of Liege, Belgium
 * Copyright (C) 2017-2022 Osimis S.A., Belgium
 * Copyright (C) 2021-2022 Sebastien Jodogne, ICTEAM UCLouvain, Belgium
 *
 * This program is free software: you can redistribute it and/or
 * modify it under the terms of the GNU Lesser 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 **/


#include "ZoomSceneTracker.h"

#include "../Scene2DViewport/ViewportController.h"
#include "../Viewport/ViewportLocker.h"

namespace OrthancStone
{
  ZoomSceneTracker::ZoomSceneTracker(boost::weak_ptr<IViewport> viewport,
                                     const PointerEvent& event,
                                     unsigned int canvasHeight) :
    viewport_(viewport),
    clickY_(event.GetMainPosition().GetY())
  {    
    ViewportLocker locker(viewport_);
    
    if (locker.IsValid())
    {
      originalSceneToCanvas_ = locker.GetController().GetSceneToCanvasTransform();

      if (canvasHeight > 3)
      {
        normalization_ = 1.0 / static_cast<double>(canvasHeight - 1);
        aligner_.reset(new Internals::FixedPointAligner(locker.GetController(), event.GetMainPosition()));
      }
    }
  }
  
  void ZoomSceneTracker::PointerMove(const PointerEvent& event,
                                     const Scene2D& scene)
  {
    static const double MIN_ZOOM = -4;
    static const double MAX_ZOOM = 4;
      
    if (aligner_.get() != NULL)
    {
      double y = event.GetMainPosition().GetY();
      
      // In the range [-1,1]
      double dy = static_cast<double>(y - clickY_) * normalization_;  
      
      double z;

      // Linear interpolation from [-1, 1] to [MIN_ZOOM, MAX_ZOOM]
      if (dy < -1.0)
      {
        z = MIN_ZOOM;
      }
      else if (dy > 1.0)
      {
        z = MAX_ZOOM;
      }
      else
      {
        z = MIN_ZOOM + (MAX_ZOOM - MIN_ZOOM) * (dy + 1.0) / 2.0;
      }

      double zoom = pow(2.0, z);

      ViewportLocker locker(viewport_);
    
      if (locker.IsValid())
      {
        locker.GetController().SetSceneToCanvasTransform(
          AffineTransform2D::Combine(
            AffineTransform2D::CreateScaling(zoom, zoom),
            originalSceneToCanvas_));
        aligner_->Apply(locker.GetController());
        locker.Invalidate();
      }
    }
  }

  void ZoomSceneTracker::Cancel(const Scene2D& scene)
  {
    ViewportLocker locker(viewport_);
    
    if (locker.IsValid())
    {
      locker.GetController().SetSceneToCanvasTransform(originalSceneToCanvas_);
      locker.Invalidate();
    }
  }
}