QGIS API Documentation  2.15.0-Master (5773d0d)
qgsrasterdrawer.cpp
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1 /***************************************************************************
2  qgsrasterdrawer.cpp
3  ---------------------
4  begin : June 2012
5  copyright : (C) 2012 by Radim Blazek
6  email : radim dot blazek at gmail.com
7  ***************************************************************************/
8 
9 /***************************************************************************
10  * *
11  * This program is free software; you can redistribute it and/or modify *
12  * it under the terms of the GNU General Public License as published by *
13  * the Free Software Foundation; either version 2 of the License, or *
14  * (at your option) any later version. *
15  * *
16  ***************************************************************************/
17 
18 #include "qgslogger.h"
19 #include "qgsrasterdrawer.h"
20 #include "qgsrasteriterator.h"
21 #include "qgsrasterviewport.h"
22 #include "qgsmaptopixel.h"
23 #include <QImage>
24 #include <QPainter>
25 #include <QPrinter>
26 
27 QgsRasterDrawer::QgsRasterDrawer( QgsRasterIterator* iterator ): mIterator( iterator )
28 {
29 }
30 
31 void QgsRasterDrawer::draw( QPainter* p, QgsRasterViewPort* viewPort, const QgsMapToPixel* theQgsMapToPixel )
32 {
33  QgsDebugMsgLevel( "Entered", 4 );
34  if ( !p || !mIterator || !viewPort || !theQgsMapToPixel )
35  {
36  return;
37  }
38 
39  // last pipe filter has only 1 band
40  int bandNumber = 1;
41  mIterator->startRasterRead( bandNumber, viewPort->mWidth, viewPort->mHeight, viewPort->mDrawnExtent );
42 
43  //number of cols/rows in output pixels
44  int nCols = 0;
45  int nRows = 0;
46  //shift to top left point for the raster part
47  int topLeftCol = 0;
48  int topLeftRow = 0;
49 
50  // We know that the output data type of last pipe filter is QImage data
51 
52  QgsRasterBlock *block;
53 
54  // readNextRasterPart calcs and resets nCols, nRows, topLeftCol, topLeftRow
55  while ( mIterator->readNextRasterPart( bandNumber, nCols, nRows,
56  &block, topLeftCol, topLeftRow ) )
57  {
58  if ( !block )
59  {
60  QgsDebugMsg( "Cannot get block" );
61  continue;
62  }
63 
64  QImage img = block->image();
65 
66  // Because of bug in Acrobat Reader we must use "white" transparent color instead
67  // of "black" for PDF. See #9101.
68  QPrinter *printer = dynamic_cast<QPrinter *>( p->device() );
69  if ( printer && printer->outputFormat() == QPrinter::PdfFormat )
70  {
71  QgsDebugMsgLevel( "PdfFormat", 4 );
72 
73  img = img.convertToFormat( QImage::Format_ARGB32 );
74  QRgb transparentBlack = qRgba( 0, 0, 0, 0 );
75  QRgb transparentWhite = qRgba( 255, 255, 255, 0 );
76  for ( int x = 0; x < img.width(); x++ )
77  {
78  for ( int y = 0; y < img.height(); y++ )
79  {
80  if ( img.pixel( x, y ) == transparentBlack )
81  {
82  img.setPixel( x, y, transparentWhite );
83  }
84  }
85  }
86  }
87 
88  drawImage( p, viewPort, img, topLeftCol, topLeftRow, theQgsMapToPixel );
89 
90  delete block;
91  }
92 }
93 
94 void QgsRasterDrawer::drawImage( QPainter* p, QgsRasterViewPort* viewPort, const QImage& img, int topLeftCol, int topLeftRow, const QgsMapToPixel* theQgsMapToPixel ) const
95 {
96  if ( !p || !viewPort )
97  {
98  return;
99  }
100 
101  //top left position in device coords
102  QPoint tlPoint = QPoint( viewPort->mTopLeftPoint.x() + topLeftCol, viewPort->mTopLeftPoint.y() + topLeftRow );
103  p->save();
104  p->setRenderHint( QPainter::Antialiasing, false );
105 
106  // Blending problem was reported with PDF output if background color has alpha < 255
107  // in #7766, it seems to be a bug in Qt, setting a brush with alpha 255 is a workaround
108  // which should not harm anything
109  p->setBrush( QBrush( QColor( Qt::white ), Qt::NoBrush ) );
110 
111  if ( theQgsMapToPixel )
112  {
113  int w = theQgsMapToPixel->mapWidth();
114  int h = theQgsMapToPixel->mapHeight();
115 
116  double rotation = theQgsMapToPixel->mapRotation();
117  if ( rotation )
118  {
119  // both viewPort and image sizes are dependent on scale
120  double cx = w / 2.0;
121  double cy = h / 2.0;
122  p->translate( cx, cy );
123  p->rotate( rotation );
124  p->translate( -cx, -cy );
125  }
126  }
127 
128  p->drawImage( tlPoint, img );
129 
130 #if 0
131  // For debugging:
132  QRectF br = QRectF( tlPoint, img.size() );
133  QPointF c = br.center();
134  double rad = std::max( br.width(), br.height() ) / 10;
135  p->drawRoundedRect( br, rad, rad );
136  p->drawLine( QLineF( br.x(), br.y(), br.x() + br.width(), br.y() + br.height() ) );
137  p->drawLine( QLineF( br.x() + br.width(), br.y(), br.x(), br.y() + br.height() ) );
138 
139  double nw = br.width() * 0.5;
140  double nh = br.height() * 0.5;
141  br = QRectF( c - QPointF( nw / 2, nh / 2 ), QSize( nw, nh ) );
142  p->drawRoundedRect( br, rad, rad );
143 
144  nw = br.width() * 0.5;
145  nh = br.height() * 0.5;
146  br = QRectF( c - QPointF( nw / 2, nh / 2 ), QSize( nw, nh ) );
147  p->drawRoundedRect( br, rad, rad );
148 #endif
149 
150  p->restore();
151 }
152 
int mapWidth() const
Return current map width in pixels The information is only known if setRotation was used...
QImage convertToFormat(Format format, QFlags< Qt::ImageConversionFlag > flags) const
Iterator for sequentially processing raster cells.
void setRenderHint(RenderHint hint, bool on)
void startRasterRead(int bandNumber, int nCols, int nRows, const QgsRectangle &extent)
Start reading of raster band.
qreal x() const
qreal y() const
#define QgsDebugMsg(str)
Definition: qgslogger.h:33
void setPixel(int x, int y, uint index_or_rgb)
int mWidth
Width, number of columns to be rendered.
void save()
void rotate(qreal angle)
void drawLine(const QLineF &line)
double mapRotation() const
Return current map rotation in degrees.
double x() const
Get the x value of the point.
Definition: qgspoint.h:185
double ANALYSIS_EXPORT max(double x, double y)
Returns the maximum of two doubles or the first argument if both are equal.
void draw(QPainter *p, QgsRasterViewPort *viewPort, const QgsMapToPixel *theQgsMapToPixel)
Perform transforms between map coordinates and device coordinates.
Definition: qgsmaptopixel.h:34
QRgb pixel(int x, int y) const
Raster data container.
#define QgsDebugMsgLevel(str, level)
Definition: qgslogger.h:34
int width() const
void drawRoundedRect(const QRectF &rect, qreal xRadius, qreal yRadius, Qt::SizeMode mode)
QPaintDevice * device() const
QgsRasterDrawer(QgsRasterIterator *iterator)
void setBrush(const QBrush &brush)
QPointF center() const
void drawImage(QPainter *p, QgsRasterViewPort *viewPort, const QImage &img, int topLeftCol, int topLeftRow, const QgsMapToPixel *mapToPixel=nullptr) const
Draws raster part.
bool readNextRasterPart(int bandNumber, int &nCols, int &nRows, QgsRasterBlock **block, int &topLeftCol, int &topLeftRow)
Fetches next part of raster data, caller takes ownership of the block and caller should delete the bl...
void restore()
void drawImage(const QRectF &target, const QImage &image, const QRectF &source, QFlags< Qt::ImageConversionFlag > flags)
qreal width() const
int mHeight
Distance in map units from bottom edge to top edge for the part of the raster that is to be rendered...
QSize size() const
void translate(const QPointF &offset)
int mapHeight() const
Return current map height in pixels.
OutputFormat outputFormat() const
double y() const
Get the y value of the point.
Definition: qgspoint.h:193
QImage image() const
Get image if type is color.
qreal height() const
int height() const
QgsPoint mTopLeftPoint
Coordinate (in output device coordinate system) of top left corner of the part of the raster that is ...
This class provides details of the viewable area that a raster will be rendered into.
QgsRectangle mDrawnExtent
Intersection of current map extent and layer extent.