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Diffstat (limited to 'include/basebmp/scaleimage.hxx')
-rw-r--r-- | include/basebmp/scaleimage.hxx | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/include/basebmp/scaleimage.hxx b/include/basebmp/scaleimage.hxx new file mode 100644 index 000000000000..fc9022357fe6 --- /dev/null +++ b/include/basebmp/scaleimage.hxx @@ -0,0 +1,189 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#ifndef INCLUDED_BASEBMP_SCALEIMAGE_HXX +#define INCLUDED_BASEBMP_SCALEIMAGE_HXX + +#include <osl/diagnose.h> + +#include <vigra/tuple.hxx> +#include <vigra/copyimage.hxx> +#include <vigra/basicimage.hxx> +#include <vigra/iteratortraits.hxx> + +namespace basebmp +{ + +template< class SourceIter, class SourceAcc, + class DestIter, class DestAcc > +void scaleLine( SourceIter s_begin, + SourceIter s_end, + SourceAcc s_acc, + DestIter d_begin, + DestIter d_end, + DestAcc d_acc ) +{ + const int src_width = s_end - s_begin; + const int dest_width = d_end - d_begin; + + OSL_ASSERT( src_width > 0 && dest_width > 0 ); + + if( src_width >= dest_width ) + { + // shrink + int rem = 0; + while( s_begin != s_end ) + { + if( rem >= 0 ) + { + d_acc.set( s_acc(s_begin), d_begin ); + + rem -= src_width; + ++d_begin; + } + + rem += dest_width; + ++s_begin; + } + } + else + { + // enlarge + int rem = -dest_width; + while( d_begin != d_end ) + { + if( rem >= 0 ) + { + rem -= dest_width; + ++s_begin; + } + + d_acc.set( s_acc(s_begin), d_begin ); + + rem += src_width; + ++d_begin; + } + } +} + +/** Scale an image using zero order interpolation (pixel replication) + + Source and destination range must be at least one pixel wide and + high. + + @param s_begin + Start iterator for source image + + @param s_end + End iterator for source image + + @param s_acc + Source accessor + + @param d_begin + Start iterator for destination image + + @param d_end + End iterator for destination image + + @param d_acc + Destination accessor + + @param bMustCopy + When true, scaleImage always copies source, even when doing 1:1 + copy + */ +template< class SourceIter, class SourceAcc, + class DestIter, class DestAcc > +void scaleImage( SourceIter s_begin, + SourceIter s_end, + SourceAcc s_acc, + DestIter d_begin, + DestIter d_end, + DestAcc d_acc, + bool bMustCopy=false ) +{ + const int src_width ( s_end.x - s_begin.x ); + const int src_height( s_end.y - s_begin.y ); + + const int dest_width ( d_end.x - d_begin.x ); + const int dest_height( d_end.y - d_begin.y ); + + if( !bMustCopy && + src_width == dest_width && + src_height == dest_height ) + { + // no scaling involved, can simply copy + vigra::copyImage( s_begin, s_end, s_acc, + d_begin, d_acc ); + return; + } + + typedef vigra::BasicImage<typename SourceAcc::value_type> TmpImage; + typedef typename TmpImage::traverser TmpImageIter; + + TmpImage tmp_image(src_width, + dest_height); + TmpImageIter t_begin = tmp_image.upperLeft(); + + // scale in y direction + for( int x=0; x<src_width; ++x, ++s_begin.x, ++t_begin.x ) + { + typename SourceIter::column_iterator s_cbegin = s_begin.columnIterator(); + typename TmpImageIter::column_iterator t_cbegin = t_begin.columnIterator(); + + scaleLine(s_cbegin, s_cbegin+src_height, s_acc, + t_cbegin, t_cbegin+dest_height, tmp_image.accessor()); + } + + t_begin = tmp_image.upperLeft(); + + // scale in x direction + for( int y=0; y<dest_height; ++y, ++d_begin.y, ++t_begin.y ) + { + typename DestIter::row_iterator d_rbegin = d_begin.rowIterator(); + typename TmpImageIter::row_iterator t_rbegin = t_begin.rowIterator(); + + scaleLine(t_rbegin, t_rbegin+src_width, tmp_image.accessor(), + d_rbegin, d_rbegin+dest_width, d_acc); + } +} + +/** Scale an image, range tuple version + + @param bMustCopy + When true, scaleImage always copies source, even when doing 1:1 + copy + */ +template< class SourceIter, class SourceAcc, + class DestIter, class DestAcc > +inline void scaleImage( vigra::triple<SourceIter,SourceIter,SourceAcc> const& src, + vigra::triple<DestIter,DestIter,DestAcc> const& dst, + bool bMustCopy=false ) +{ + scaleImage(src.first,src.second,src.third, + dst.first,dst.second,dst.third, + bMustCopy); +} + +} + +#endif /* INCLUDED_BASEBMP_SCALEIMAGE_HXX */ + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |