displayer.cpp

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/*
  Displayer  -  base class for displaying video
 
   Copyright (C)
     2000,            Arne Schirmacher <arne@schirmacher.de>
     2001-2007,       Dan Dennedy <dan@dennedy.org>
     2008,            Joel Holdsworth <joel@airwebreathe.org.uk>
 
 **Lumiera** is free software; you can redistribute it and/or modify it
 under the terms of the GNU General Public License as published by the
 Free Software Foundation; either version 2 of the License, or (at your
 option) any later version. See the file COPYING for further details.
 
* *****************************************************************/
 
 
#include "stage/gtk-base.hpp"
#include "stage/output/displayer.hpp"
 
#include <cmath>
 
namespace stage {
namespace output {
  
  DisplayerInput
  Displayer::format()
  {
    return lumiera::DISPLAY_NONE;
  }
  
  void
  Displayer::calculateVideoLayout(
          int widgetWidth, int widgetHeight,
          int &imgOrg_x, int &imgOrg_y, int &imgWidth, int &imgHeight )
  {
    REQUIRE (0 < widgetWidth );
    REQUIRE (0 < widgetHeight);
    REQUIRE (0 < videoWidth  );
    REQUIRE (0 < videoHeight );
 
    auto ratioW = double(widgetWidth ) / videoWidth;
    auto ratioH = double(widgetHeight) / videoHeight;
    auto scale  = std::min (ratioW, ratioH);
    imgWidth  = std::lround (scale * videoWidth);
    imgHeight = std::lround (scale * videoHeight);
    imgOrg_x = (widgetWidth - imgWidth)   / 2;
    imgOrg_y = (widgetHeight - imgHeight) / 2;
    
    ENSURE (imgWidth <= widgetWidth);
    ENSURE (imgWidth <= widgetWidth);
    ENSURE (0 <= imgOrg_x and imgOrg_x < widgetWidth);
    ENSURE (0 <= imgOrg_y and imgOrg_y < widgetHeight);
  }
  
  
}} // namespace stage::output