1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
/*
dspdfviewer - Dual Screen PDF Viewer for LaTeX-Beamer
Copyright (C) 2012 Danny Edel <mail@danny-edel.de>
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 "renderutils.h"
#include "debug.h"
#include <QApplication>
#include <stdexcept>
#include <boost/math/special_functions/round.hpp>
using boost::math::iround;
namespace {
bool shuttingDown = false;
}
QImage RenderUtils::renderPagePart(QSharedPointer< const Poppler::Page > page, QSize targetSize, PagePart whichPart)
{
if ( ! page )
{
throw std::runtime_error( std::string( qPrintable( QApplication::translate("RenderUtils", "RenderUtils::renderPagePart called with null page. Target size was %1x%2").
arg(targetSize.width()).arg(targetSize.height()) ) ) );
}
if ( shuttingDown )
return QImage();
/* pagesize in points, (72 points is an inch) */
QSizeF pagesize = page->pageSizeF();
QSizeF fullsize = pagesize;
if ( whichPart != PagePart::FullPage )
{
/* Only render half the page */
pagesize.setWidth(pagesize.width()/2);
}
/* Calculate DPI for displaying on size */
/* the 72 comes from converting from points to inches */
double dpiWidth = 72.0 * targetSize.width() / pagesize.width();
double dpiHeight = 72.0 * targetSize.height() / pagesize.height();
/* Take the smaller one, so that the image surely fits on target area */
double dpi = std::min(dpiWidth, dpiHeight);
/* Calculate Page Size in pixels */
QSize fullSizePixels( iround(dpi * fullsize.width() / 72.0),
iround(dpi * fullsize.height() / 72.0) );
/* Calculate rendered image size */
QSize imageSizePixels( iround(dpi * pagesize.width() / 72.0),
iround( dpi * pagesize.height() / 72.0 ) );
/* Calculate x-offset */
int x = 0;
if ( whichPart == PagePart::RightHalf ) {
/* start at an offset of width() pixels to the right, rounding up */
x = (fullSizePixels.width()+1)/2;
}
/* render it */
QImage renderedImage = page->renderToImage(
dpi, dpi,
x, /* x-offset */
0, /* y-offset */
imageSizePixels.width(),
imageSizePixels.height()
);
return renderedImage;
}
void RenderUtils::notifyShutdown(void) {
shuttingDown = true;
}
|
