You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
78 lines
2.8 KiB
78 lines
2.8 KiB
/*
|
|
|
|
Copyright (C) 2005 Lubos Lunak <l.lunak@kde.org>
|
|
|
|
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
|
|
|
*/
|
|
|
|
#include "croppedqimage.h"
|
|
|
|
namespace ImageUtils
|
|
{
|
|
|
|
// This class is used in ImageView::performPaint(). Just using QImage::copy( QRect )
|
|
// takes a significant time with very large images. So instead of copying the image data
|
|
// just create CroppedQImage which fakes a subimage by manipulating its scanline pointers.
|
|
// That will of course break if something doesn't use scanlines but accesses the image
|
|
// data directly, QImage::copy() being the most notable case. There are two ways
|
|
// to handle that: 1) It is possible to manually call normalize() which will make
|
|
// CroppedQImage copy the image data and own it, just like proper QImage. 2) CroppedQImage
|
|
// has as a data member also QImage holding the original image. This ensures that all
|
|
// the original image data are still available for the whole lifetime of CroppedQImage.
|
|
|
|
CroppedQImage::CroppedQImage( const QImage& im, const QRect& rect )
|
|
: QImage( rect.size(), im.depth(), im.numColors(), im.bitOrder())
|
|
, orig( im )
|
|
{
|
|
if( im.isNull())
|
|
return;
|
|
memcpy( colorTable(), im.colorTable(), im.numColors() * sizeof( QRgb ));
|
|
setAlphaBuffer( im.hasAlphaBuffer());
|
|
setDotsPerMeterX( im.dotsPerMeterX());
|
|
setDotsPerMeterY( im.dotsPerMeterY());
|
|
//data->offset = im.offset();
|
|
// make scanlines point to right places in the original QImage
|
|
for( int i = 0;
|
|
i < height();
|
|
++i )
|
|
jumpTable()[ i ] = im.scanLine( rect.y() + i ) + rect.x() * ( depth() / 8 );
|
|
}
|
|
|
|
CroppedQImage& CroppedQImage::operator= ( const QImage& im )
|
|
{
|
|
QImage::operator=( im );
|
|
return *this;
|
|
}
|
|
|
|
void CroppedQImage::normalize()
|
|
{
|
|
// is it a normal QImage with its own data?
|
|
uchar* firstdata = ( uchar* )( jumpTable() + height());
|
|
if( scanLine( 0 ) == firstdata )
|
|
return;
|
|
// copy the image data to our own data and make scanlines point properly there
|
|
for( int i = 0;
|
|
i < height();
|
|
++i )
|
|
{
|
|
uchar* oldline = scanLine( i );
|
|
jumpTable()[ i ] = firstdata + i * bytesPerLine();
|
|
memcpy( scanLine( i ), oldline, bytesPerLine());
|
|
}
|
|
}
|
|
|
|
} // namespace
|