gui/output/displayer.cpp

/*
  displayer.cpp  -  Implements the base class for displaying video
 
  Copyright (C)         Lumiera.org
    2000,               Arne Schirmacher <arne@schirmacher.de>
    2001-2007,          Dan Dennedy <dan@dennedy.org>
    2008,               Joel Holdsworth <joel@airwebreathe.org.uk>
 
  This program 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.
 
  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 General Public License for more details.
 
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 
* *****************************************************/

#include "../gtk-lumiera.hpp"
#include "displayer.hpp"
#include "xvdisplayer.hpp"
#include "gdkdisplayer.hpp"

namespace gui {
namespace output {

bool
Displayer::usable()
  {
    return false;
  }

DisplayerInput
Displayer::format()
  {
    return DISPLAY_NONE;
  }

int
Displayer::preferredWidth()
  {
    return imageWidth;
  }

int
Displayer::preferredHeight()
  {
    return imageHeight;
  }

void
Displayer::calculateVideoLayout(
        int widget_width, int widget_height,
        int image_width, int image_height,
        int &video_x, int &video_y, int &video_width, int &video_height )
  {
    REQUIRE(widget_width >= 0);
    REQUIRE(widget_height >= 0);
    REQUIRE(image_width >= 0);
    REQUIRE(image_height >= 0);

    double ratio_width = ( double ) widget_width / ( double ) image_width;
    double ratio_height = ( double ) widget_height / ( double ) image_height;
    double ratio_constant = ratio_height < ratio_width ?
                           ratio_height : ratio_width;
    video_width = ( int ) ( image_width * ratio_constant + 0.5 );
    video_height = ( int ) ( image_height * ratio_constant + 0.5 );
    video_x = ( widget_width - video_width ) / 2;
    video_y = ( widget_height - video_height ) / 2;
    
    ENSURE(video_x >= 0 && video_x < widget_width)
    ENSURE(video_y >= 0 && video_y < widget_height)
    ENSURE(video_width <= widget_width)
    ENSURE(video_width <= widget_width)
  }

}   // namespace output
}   // namespace gui

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