libreoffice/slideshow/source/engine/transitions/doublediamondwipe.cxx

/*************************************************************************
 *
 *  OpenOffice.org - a multi-platform office productivity suite
 *
 *  $RCSfile: doublediamondwipe.cxx,v $
 *
 *  $Revision: 1.5 $
 *
 *  last change: $Author: kz $ $Date: 2006-12-13 15:39:50 $
 *
 *  The Contents of this file are made available subject to
 *  the terms of GNU Lesser General Public License Version 2.1.
 *
 *
 *    GNU Lesser General Public License Version 2.1
 *    =============================================
 *    Copyright 2005 by Sun Microsystems, Inc.
 *    901 San Antonio Road, Palo Alto, CA 94303, USA
 *
 *    This library is free software; you can redistribute it and/or
 *    modify it under the terms of the GNU Lesser General Public
 *    License version 2.1, as published by the Free Software Foundation.
 *
 *    This library 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 library; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *    MA  02111-1307  USA
 *
 ************************************************************************/

// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_slideshow.hxx"

#include <canvas/debug.hxx>
#include <basegfx/matrix/b2dhommatrix.hxx>
#include <basegfx/point/b2dpoint.hxx>
#include "doublediamondwipe.hxx"


namespace slideshow {
namespace internal {

::basegfx::B2DPolyPolygon DoubleDiamondWipe::operator () ( double t )
{
    // outer:
    const double a = ::basegfx::pruneScaleValue( 0.25 + (t * 0.75) );
    ::basegfx::B2DPolygon poly;
    poly.append( ::basegfx::B2DPoint( 0.5 + a, 0.5 ) );
    poly.append( ::basegfx::B2DPoint( 0.5, 0.5 - a ) );
    poly.append( ::basegfx::B2DPoint( 0.5 - a, 0.5 ) );
    poly.append( ::basegfx::B2DPoint( 0.5, 0.5 + a ) );
    poly.setClosed(true);
    ::basegfx::B2DPolyPolygon res(poly);

    // inner (reverse order to clip):
    const double b = ::basegfx::pruneScaleValue( (1.0 - t) * 0.25 );
    poly.clear();
    poly.append( ::basegfx::B2DPoint( 0.5 + b, 0.5 ) );
    poly.append( ::basegfx::B2DPoint( 0.5, 0.5 + b ) );
    poly.append( ::basegfx::B2DPoint( 0.5 - b, 0.5 ) );
    poly.append( ::basegfx::B2DPoint( 0.5, 0.5 - b ) );
    poly.setClosed(true);
    res.append(poly);

    return res;
}

}
}