QGIS API Documentation  2.99.0-Master (dcec6bb)
qgssinglebandcolordatarenderer.cpp
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1 /***************************************************************************
2  qgssinglebandcolordatarenderer.cpp
3  ----------------------------------
4  begin : January 2012
5  copyright : (C) 2012 by Marco Hugentobler
6  email : marco at sourcepole dot ch
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 
19 #include "qgsrastertransparency.h"
20 #include "qgsrasterviewport.h"
21 #include <QDomDocument>
22 #include <QDomElement>
23 #include <QImage>
24 #include <memory>
25 
27  QgsRasterRenderer( input, QStringLiteral( "singlebandcolordata" ) ), mBand( band )
28 {
29 
30 }
31 
33 {
34  QgsSingleBandColorDataRenderer *renderer = new QgsSingleBandColorDataRenderer( nullptr, mBand );
35  renderer->copyCommonProperties( this );
36  return renderer;
37 }
38 
40 {
41  if ( elem.isNull() )
42  {
43  return nullptr;
44  }
45 
46  int band = elem.attribute( QStringLiteral( "band" ), QStringLiteral( "-1" ) ).toInt();
47  QgsRasterRenderer *r = new QgsSingleBandColorDataRenderer( input, band );
48  r->readXml( elem );
49  return r;
50 }
51 
52 QgsRasterBlock *QgsSingleBandColorDataRenderer::block( int bandNo, QgsRectangle const &extent, int width, int height, QgsRasterBlockFeedback *feedback )
53 {
54  Q_UNUSED( bandNo );
55 
56  std::unique_ptr< QgsRasterBlock > outputBlock( new QgsRasterBlock() );
57  if ( !mInput )
58  {
59  return outputBlock.release();
60  }
61 
62  std::unique_ptr< QgsRasterBlock > inputBlock( mInput->block( mBand, extent, width, height, feedback ) );
63  if ( !inputBlock || inputBlock->isEmpty() )
64  {
65  QgsDebugMsg( "No raster data!" );
66  return outputBlock.release();
67  }
68 
69  bool hasTransparency = usesTransparency();
70  if ( !hasTransparency )
71  {
72  // Nothing to do, just retype if necessary
73  inputBlock->convert( Qgis::ARGB32_Premultiplied );
74  return inputBlock.release();
75  }
76 
77  if ( !outputBlock->reset( Qgis::ARGB32_Premultiplied, width, height ) )
78  {
79  return outputBlock.release();
80  }
81 
82  // make sure input is also premultiplied!
83  inputBlock->convert( Qgis::ARGB32_Premultiplied );
84 
85  QRgb *inputBits = ( QRgb * )inputBlock->bits();
86  QRgb *outputBits = ( QRgb * )outputBlock->bits();
87  for ( qgssize i = 0; i < ( qgssize )width * height; i++ )
88  {
89  QRgb c = inputBits[i];
90  outputBits[i] = qRgba( mOpacity * qRed( c ), mOpacity * qGreen( c ), mOpacity * qBlue( c ), mOpacity * qAlpha( c ) );
91  }
92 
93  return outputBlock.release();
94 }
95 
96 void QgsSingleBandColorDataRenderer::writeXml( QDomDocument &doc, QDomElement &parentElem ) const
97 {
98  if ( parentElem.isNull() )
99  return;
100 
101  QDomElement rasterRendererElem = doc.createElement( QStringLiteral( "rasterrenderer" ) );
102  _writeXml( doc, rasterRendererElem );
103  rasterRendererElem.setAttribute( QStringLiteral( "band" ), mBand );
104  parentElem.appendChild( rasterRendererElem );
105 }
106 
108 {
109  QList<int> bandList;
110  if ( mBand != -1 )
111  {
112  bandList << mBand;
113  }
114  return bandList;
115 }
116 
118 {
119  // Renderer can only work with numerical values in at least 1 band
120  if ( !input ) return false;
121 
122  if ( !mOn )
123  {
124  // In off mode we can connect to anything
125  mInput = input;
126  return true;
127  }
128 
129  if ( input->dataType( 1 ) == Qgis::ARGB32 ||
130  input->dataType( 1 ) == Qgis::ARGB32_Premultiplied )
131  {
132  mInput = input;
133  return true;
134  }
135  return false;
136 }
A rectangle specified with double values.
Definition: qgsrectangle.h:38
bool setInput(QgsRasterInterface *input) override
Set input.
virtual QgsRectangle extent() const
Get the extent of the interface.
QgsRasterBlock * block(int bandNo, const QgsRectangle &extent, int width, int height, QgsRasterBlockFeedback *feedback=nullptr) override
Read block of data using given extent and size.
#define QgsDebugMsg(str)
Definition: qgslogger.h:37
virtual QgsRasterInterface * input() const
Current input.
QgsSingleBandColorDataRenderer * clone() const override
Clone itself, create deep copy.
void writeXml(QDomDocument &doc, QDomElement &parentElem) const override
Write base class members to xml.
QgsSingleBandColorDataRenderer(QgsRasterInterface *input, int band)
virtual Qgis::DataType dataType(int bandNo) const =0
Returns data type for the band specified by number.
Raster renderer pipe for single band color.
Color, alpha, red, green, blue, 4 bytes the same as QImage::Format_ARGB32_Premultiplied.
Definition: qgis.h:89
Raster data container.
virtual QgsRasterBlock * block(int bandNo, const QgsRectangle &extent, int width, int height, QgsRasterBlockFeedback *feedback=nullptr)=0
Read block of data using given extent and size.
void _writeXml(QDomDocument &doc, QDomElement &rasterRendererElem) const
Write upper class info into rasterrenderer element (called by writeXml method of subclasses) ...
void copyCommonProperties(const QgsRasterRenderer *other, bool copyMinMaxOrigin=true)
Copies common properties like opacity / transparency data from other renderer.
bool usesTransparency() const
void readXml(const QDomElement &rendererElem) override
Sets base class members from xml. Usually called from create() methods of subclasses.
Base class for processing filters like renderers, reprojector, resampler etc.
unsigned long long qgssize
Qgssize is used instead of size_t, because size_t is stdlib type, unknown by SIP, and it would be har...
Definition: qgis.h:348
QList< int > usesBands() const override
Returns a list of band numbers used by the renderer.
static QgsRasterRenderer * create(const QDomElement &elem, QgsRasterInterface *input)
double mOpacity
Global alpha value (0-1)
QgsRasterInterface * mInput
Feedback object tailored for raster block reading.
Raster renderer pipe that applies colors to a raster.
Color, alpha, red, green, blue, 4 bytes the same as QImage::Format_ARGB32.
Definition: qgis.h:88