Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
       2             : /*
       3             :  * This file is part of the LibreOffice project.
       4             :  *
       5             :  * This Source Code Form is subject to the terms of the Mozilla Public
       6             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       7             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
       8             :  *
       9             :  * This file incorporates work covered by the following license notice:
      10             :  *
      11             :  *   Licensed to the Apache Software Foundation (ASF) under one or more
      12             :  *   contributor license agreements. See the NOTICE file distributed
      13             :  *   with this work for additional information regarding copyright
      14             :  *   ownership. The ASF licenses this file to you under the Apache
      15             :  *   License, Version 2.0 (the "License"); you may not use this file
      16             :  *   except in compliance with the License. You may obtain a copy of
      17             :  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
      18             :  */
      19             : 
      20             : #include <basegfx/tools/keystoplerp.hxx>
      21             : #include <com/sun/star/uno/Sequence.hxx>
      22             : 
      23             : #include <algorithm>
      24             : 
      25           2 : static void validateInput(const std::vector<double>& rKeyStops)
      26             : {
      27             :     (void)rKeyStops;
      28             : #ifdef DBG_UTIL
      29             :     OSL_ENSURE( rKeyStops.size() > 1,
      30             :                 "KeyStopLerp::KeyStopLerp(): key stop vector must have two entries or more" );
      31             : 
      32             :     // rKeyStops must be sorted in ascending order
      33             :     for( ::std::size_t i=1, len=rKeyStops.size(); i<len; ++i )
      34             :     {
      35             :         if( rKeyStops[i-1] > rKeyStops[i] )
      36             :             OSL_FAIL( "KeyStopLerp::KeyStopLerp(): time vector is not sorted in ascending order!" );
      37             :     }
      38             : #endif
      39           2 : }
      40             : 
      41             : namespace basegfx
      42             : {
      43             :     namespace tools
      44             :     {
      45           2 :         KeyStopLerp::KeyStopLerp( const std::vector<double>& rKeyStops ) :
      46             :             maKeyStops(rKeyStops),
      47           2 :             mnLastIndex(0)
      48             :         {
      49           2 :             validateInput(maKeyStops);
      50           2 :         }
      51             : 
      52           0 :         KeyStopLerp::KeyStopLerp( const ::com::sun::star::uno::Sequence<double>& rKeyStops ) :
      53           0 :             maKeyStops(rKeyStops.getLength()),
      54           0 :             mnLastIndex(0)
      55             :         {
      56             :             std::copy( rKeyStops.getConstArray(),
      57           0 :                        rKeyStops.getConstArray()+rKeyStops.getLength(),
      58           0 :                        maKeyStops.begin() );
      59           0 :             validateInput(maKeyStops);
      60           0 :         }
      61             : 
      62          14 :         KeyStopLerp::ResultType KeyStopLerp::lerp(double fAlpha) const
      63             :         {
      64             :             // cached value still okay?
      65          18 :             if( maKeyStops.at(mnLastIndex) < fAlpha ||
      66           4 :                 maKeyStops.at(mnLastIndex+1) >= fAlpha )
      67             :             {
      68             :                 // nope, find new index
      69             :                 mnLastIndex = std::min<std::ptrdiff_t>(
      70          14 :                     maKeyStops.size()-2,
      71             :                     // range is ensured by max below
      72             :                     std::max<std::ptrdiff_t>(
      73             :                         0,
      74             :                         std::distance( maKeyStops.begin(),
      75             :                                        std::lower_bound( maKeyStops.begin(),
      76             :                                                          maKeyStops.end(),
      77          28 :                                                          fAlpha )) - 1 ));
      78             :             }
      79             : 
      80             :             // lerp between stop and stop+1
      81             :             const double fRawLerp=
      82          28 :                 (fAlpha-maKeyStops.at(mnLastIndex)) /
      83          28 :                 (maKeyStops.at(mnLastIndex+1) - maKeyStops.at(mnLastIndex));
      84             : 
      85             :             // clamp to permissible range (input fAlpha might be
      86             :             // everything)
      87             :             return ResultType(
      88             :                 mnLastIndex,
      89          14 :                 clamp(fRawLerp,0.0,1.0));
      90             :         }
      91             :     }
      92             : }
      93             : 
      94             : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */