QGIS API Documentation 3.27.0-Master (f261cc1f8b)
qgsrasterrenderer.cpp
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1/***************************************************************************
2 qgsrasterrenderer.cpp
3 ---------------------
4 begin : December 2011
5 copyright : (C) 2011 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
18#include "qgsrasterrenderer.h"
20
21#include "qgssymbollayerutils.h"
23
24#include <QCoreApplication>
25#include <QDomDocument>
26#include <QDomElement>
27#include <QImage>
28#include <QPainter>
29
30// See #9101 before any change of NODATA_COLOR!
31const QRgb QgsRasterRenderer::NODATA_COLOR = qRgba( 0, 0, 0, 0 );
32
34 : QgsRasterInterface( input )
35 , mType( type )
36{
37}
38
40{
42}
43
45{
46 if ( mOn ) return 1;
47
48 if ( mInput ) return mInput->bandCount();
49
50 return 0;
51}
52
54{
55 QgsDebugMsgLevel( QStringLiteral( "Entered" ), 4 );
56
58
59 if ( mInput ) return mInput->dataType( bandNo );
60
62}
63
65{
66 // Renderer can only work with numerical values in at least 1 band
67 if ( !input ) return false;
68
69 if ( !mOn )
70 {
71 // In off mode we can connect to anything
72 mInput = input;
73 return true;
74 }
75
76 for ( int i = 1; i <= input->bandCount(); i++ )
77 {
78 const Qgis::DataType bandType = input->dataType( i );
79 // we always allow unknown data types to connect - otherwise invalid layers cannot setup
80 // their original rendering pipe and this information is lost
81 if ( bandType != Qgis::DataType::UnknownDataType && !QgsRasterBlock::typeIsNumeric( bandType ) )
82 {
83 return false;
84 }
85 }
86 mInput = input;
87 return true;
88}
89
91{
92 if ( !mInput )
93 {
94 return true;
95 }
96 return ( mAlphaBand > 0 || ( mRasterTransparency && !mRasterTransparency->isEmpty() ) || !qgsDoubleNear( mOpacity, 1.0 ) );
97}
98
100{
101 delete mRasterTransparency;
103}
104
105QList< QPair< QString, QColor > > QgsRasterRenderer::legendSymbologyItems() const
106{
107 return QList< QPair< QString, QColor > >();
108}
109
110QList<QgsLayerTreeModelLegendNode *> QgsRasterRenderer::createLegendNodes( QgsLayerTreeLayer *nodeLayer )
111{
112 QList<QgsLayerTreeModelLegendNode *> nodes;
113
114 const QList< QPair< QString, QColor > > rasterItemList = legendSymbologyItems();
115 if ( rasterItemList.isEmpty() )
116 return nodes;
117
118 // Paletted raster may have many colors, for example UInt16 may have 65536 colors
119 // and it is very slow, so we limit max count
120 int count = 0;
121 const int max_count = 1000;
122
123 for ( auto itemIt = rasterItemList.constBegin(); itemIt != rasterItemList.constEnd(); ++itemIt, ++count )
124 {
125 nodes << new QgsRasterSymbolLegendNode( nodeLayer, itemIt->second, itemIt->first );
126
127 if ( count == max_count )
128 {
129 const QString label = tr( "following %1 items\nnot displayed" ).arg( rasterItemList.size() - max_count );
130 nodes << new QgsSimpleLegendNode( nodeLayer, label );
131 break;
132 }
133 }
134
135 return nodes;
136}
137
138void QgsRasterRenderer::_writeXml( QDomDocument &doc, QDomElement &rasterRendererElem ) const
139{
140 if ( rasterRendererElem.isNull() )
141 {
142 return;
143 }
144
145 rasterRendererElem.setAttribute( QStringLiteral( "type" ), mType );
146 rasterRendererElem.setAttribute( QStringLiteral( "opacity" ), QString::number( mOpacity ) );
147 rasterRendererElem.setAttribute( QStringLiteral( "alphaBand" ), mAlphaBand );
148 rasterRendererElem.setAttribute( QStringLiteral( "nodataColor" ), mNodataColor.isValid() ? QgsSymbolLayerUtils::encodeColor( mNodataColor ) : QString() );
149
151 {
152 mRasterTransparency->writeXml( doc, rasterRendererElem );
153 }
154
155 QDomElement minMaxOriginElem = doc.createElement( QStringLiteral( "minMaxOrigin" ) );
156 mMinMaxOrigin.writeXml( doc, minMaxOriginElem );
157 rasterRendererElem.appendChild( minMaxOriginElem );
158}
159
161{
162 if ( !mNodataColor.isValid() )
163 return NODATA_COLOR;
164 else
165 return mNodataColor.rgba();
166}
167
168void QgsRasterRenderer::readXml( const QDomElement &rendererElem )
169{
170 if ( rendererElem.isNull() )
171 {
172 return;
173 }
174
175 mType = rendererElem.attribute( QStringLiteral( "type" ) );
176 mOpacity = rendererElem.attribute( QStringLiteral( "opacity" ), QStringLiteral( "1.0" ) ).toDouble();
177 mAlphaBand = rendererElem.attribute( QStringLiteral( "alphaBand" ), QStringLiteral( "-1" ) ).toInt();
178 const QString colorEncoded = rendererElem.attribute( QStringLiteral( "nodataColor" ) );
179 mNodataColor = !colorEncoded.isEmpty() ? QgsSymbolLayerUtils::decodeColor( colorEncoded ) : QColor();
180
181 const QDomElement rasterTransparencyElem = rendererElem.firstChildElement( QStringLiteral( "rasterTransparency" ) );
182 if ( !rasterTransparencyElem.isNull() )
183 {
184 delete mRasterTransparency;
186 mRasterTransparency->readXml( rasterTransparencyElem );
187 }
188
189 const QDomElement minMaxOriginElem = rendererElem.firstChildElement( QStringLiteral( "minMaxOrigin" ) );
190 if ( !minMaxOriginElem.isNull() )
191 {
192 mMinMaxOrigin.readXml( minMaxOriginElem );
193 }
194}
195
196void QgsRasterRenderer::copyCommonProperties( const QgsRasterRenderer *other, bool copyMinMaxOrigin )
197{
198 if ( !other )
199 return;
200
201 setOpacity( other->opacity() );
202 setAlphaBand( other->alphaBand() );
204 setNodataColor( other->nodataColor() );
205 if ( copyMinMaxOrigin )
206 setMinMaxOrigin( other->minMaxOrigin() );
207}
208
209void QgsRasterRenderer::toSld( QDomDocument &doc, QDomElement &element, const QVariantMap & ) const
210{
211 QDomElement rasterSymbolizerElem = doc.createElement( QStringLiteral( "sld:RasterSymbolizer" ) );
212 element.appendChild( rasterSymbolizerElem );
213
214 // add opacity only is different from default
215 if ( !qgsDoubleNear( opacity(), 1.0 ) )
216 {
217 QDomElement opacityElem = doc.createElement( QStringLiteral( "sld:Opacity" ) );
218 opacityElem.appendChild( doc.createTextNode( QString::number( opacity() ) ) );
219 rasterSymbolizerElem.appendChild( opacityElem );
220 }
221}
222
224{
225 return true;
226}
DataType
Raster data types.
Definition: qgis.h:129
@ ARGB32_Premultiplied
Color, alpha, red, green, blue, 4 bytes the same as QImage::Format_ARGB32_Premultiplied.
@ UnknownDataType
Unknown or unspecified type.
Layer tree node points to a map layer.
static bool typeIsNumeric(Qgis::DataType type)
Returns true if data type is numeric.
Base class for processing filters like renderers, reprojector, resampler etc.
virtual Qgis::DataType dataType(int bandNo) const =0
Returns data type for the band specified by number.
virtual int bandCount() const =0
Gets number of bands.
QgsRasterInterface * mInput
virtual QgsRasterInterface * input() const
Current input.
void writeXml(QDomDocument &doc, QDomElement &parentElem) const
Serialize object.
void readXml(const QDomElement &elem)
Deserialize object.
Raster renderer pipe that applies colors to a raster.
QColor nodataColor() const
Returns the color to use for shading nodata pixels.
QgsRasterRenderer(QgsRasterInterface *input=nullptr, const QString &type=QString())
Constructor for QgsRasterRenderer.
double mOpacity
Global alpha value (0-1)
bool setInput(QgsRasterInterface *input) override
Set input.
void setMinMaxOrigin(const QgsRasterMinMaxOrigin &origin)
Sets origin of min/max values.
~QgsRasterRenderer() override
int mAlphaBand
Read alpha value from band.
QRgb renderColorForNodataPixel() const
Returns the color for the renderer to use to represent nodata pixels.
const QgsRasterTransparency * rasterTransparency() const
const QgsRasterMinMaxOrigin & minMaxOrigin() const
Returns const reference to origin of min/max values.
void _writeXml(QDomDocument &doc, QDomElement &rasterRendererElem) const
Write upper class info into rasterrenderer element (called by writeXml method of subclasses)
int bandCount() const override
Gets number of bands.
double opacity() const
Returns the opacity for the renderer, where opacity is a value between 0 (totally transparent) and 1....
void setAlphaBand(int band)
void setOpacity(double opacity)
Sets the opacity for the renderer, where opacity is a value between 0 (totally transparent) and 1....
QgsRasterMinMaxOrigin mMinMaxOrigin
Origin of min/max values.
QgsRasterTransparency * mRasterTransparency
Raster transparency per color or value. Overwrites global alpha value.
virtual QList< QgsLayerTreeModelLegendNode * > createLegendNodes(QgsLayerTreeLayer *nodeLayer)
Creates a set of legend nodes representing the renderer.
void setRasterTransparency(QgsRasterTransparency *t)
virtual bool accept(QgsStyleEntityVisitorInterface *visitor) const
Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer...
bool usesTransparency() const
void copyCommonProperties(const QgsRasterRenderer *other, bool copyMinMaxOrigin=true)
Copies common properties like opacity / transparency data from other renderer.
static const QRgb NODATA_COLOR
virtual void toSld(QDomDocument &doc, QDomElement &element, const QVariantMap &props=QVariantMap()) const
Used from subclasses to create SLD Rule elements following SLD v1.0 specs.
void setNodataColor(const QColor &color)
Sets the color to use for shading nodata pixels.
virtual QList< QPair< QString, QColor > > legendSymbologyItems() const
Returns symbology items if provided by renderer.
void readXml(const QDomElement &rendererElem) override
Sets base class members from xml. Usually called from create() methods of subclasses.
Qgis::DataType dataType(int bandNo) const override
Returns data type for the band specified by number.
Implementation of legend node interface for displaying raster legend entries.
Defines the list of pixel values to be considered as transparent or semi transparent when rendering r...
void writeXml(QDomDocument &doc, QDomElement &parentElem) const
Writes the transparency information to an XML document.
bool isEmpty() const
True if there are no entries in the pixel lists except the nodata value.
void readXml(const QDomElement &elem)
Reads the transparency information from an XML document.
Implementation of legend node interface for displaying arbitrary label with icon.
An interface for classes which can visit style entity (e.g.
static QColor decodeColor(const QString &str)
static QString encodeColor(const QColor &color)
bool qgsDoubleNear(double a, double b, double epsilon=4 *std::numeric_limits< double >::epsilon())
Compare two doubles (but allow some difference)
Definition: qgis.h:2396
#define QgsDebugMsgLevel(str, level)
Definition: qgslogger.h:39