QGIS API Documentation 3.27.0-Master (0a97e3138f)
qgsrastertransparency.cpp
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1/* **************************************************************************
2 qgsrastertransparency.cpp - description
3 -------------------
4begin : Mon Nov 30 2007
5copyright : (C) 2007 by Peter J. Ersts
7
8****************************************************************************/
9
10/* **************************************************************************
11 * *
12 * This program is free software; you can redistribute it and/or modify *
13 * it under the terms of the GNU General Public License as published by *
14 * the Free Software Foundation; either version 2 of the License, or *
15 * (at your option) any later version. *
16 * *
17 ***************************************************************************/
18
19#include "qgsrasterinterface.h"
21#include "qgis.h"
22#include "qgslogger.h"
23
24#include <QDomDocument>
25#include <QDomElement>
26
27QList<QgsRasterTransparency::TransparentSingleValuePixel> QgsRasterTransparency::transparentSingleValuePixelList() const
28{
29 return mTransparentSingleValuePixelList;
30}
31
32QList<QgsRasterTransparency::TransparentThreeValuePixel> QgsRasterTransparency::transparentThreeValuePixelList() const
33{
34 return mTransparentThreeValuePixelList;
35}
36
38{
39 //clear the existing list
40 mTransparentSingleValuePixelList.clear();
41
42 //add the initial value
43 TransparentSingleValuePixel myTransparentSingleValuePixel;
44 myTransparentSingleValuePixel.min = value;
45 myTransparentSingleValuePixel.max = value;
46 myTransparentSingleValuePixel.percentTransparent = 100.0;
47 mTransparentSingleValuePixelList.append( myTransparentSingleValuePixel );
48}
49
50void QgsRasterTransparency::initializeTransparentPixelList( double redValue, double greenValue, double blueValue )
51{
52 //clearn the existing list
53 mTransparentThreeValuePixelList.clear();
54
55 //add the initial values
56 TransparentThreeValuePixel myTransparentThreeValuePixel;
57 myTransparentThreeValuePixel.red = redValue;
58 myTransparentThreeValuePixel.green = greenValue;
59 myTransparentThreeValuePixel.blue = blueValue;
60 myTransparentThreeValuePixel.percentTransparent = 100.0;
61 mTransparentThreeValuePixelList.append( myTransparentThreeValuePixel );
62}
63
64void QgsRasterTransparency::setTransparentSingleValuePixelList( const QList<QgsRasterTransparency::TransparentSingleValuePixel> &newList )
65{
66 mTransparentSingleValuePixelList = newList;
67}
68
69void QgsRasterTransparency::setTransparentThreeValuePixelList( const QList<QgsRasterTransparency::TransparentThreeValuePixel> &newList )
70{
71 mTransparentThreeValuePixelList = newList;
72}
73
74int QgsRasterTransparency::alphaValue( double value, int globalTransparency ) const
75{
76 //if NaN return 0, transparent
77 if ( std::isnan( value ) )
78 {
79 return 0;
80 }
81
82 //Search through the transparency list looking for a match
83 bool myTransparentPixelFound = false;
84 TransparentSingleValuePixel myTransparentPixel = {0, 0, 100};
85 for ( int myListRunner = 0; myListRunner < mTransparentSingleValuePixelList.count(); myListRunner++ )
86 {
87 myTransparentPixel = mTransparentSingleValuePixelList[myListRunner];
88 if ( ( value >= myTransparentPixel.min && value <= myTransparentPixel.max ) ||
89 qgsDoubleNear( value, myTransparentPixel.min ) ||
90 qgsDoubleNear( value, myTransparentPixel.max ) )
91 {
92 myTransparentPixelFound = true;
93 break;
94 }
95 }
96
97 //if a match was found use the stored transparency percentage
98 if ( myTransparentPixelFound )
99 {
100 return static_cast< int >( static_cast< float >( globalTransparency ) * ( 1.0 - ( myTransparentPixel.percentTransparent / 100.0 ) ) );
101 }
102
103 return globalTransparency;
104}
105
106int QgsRasterTransparency::alphaValue( double redValue, double greenValue, double blueValue, int globalTransparency ) const
107{
108 //if NaN return 0, transparent
109 if ( std::isnan( redValue ) || std::isnan( greenValue ) || std::isnan( blueValue ) )
110 {
111 return 0;
112 }
113
114 //Search through the transparency list looking for a match
115 bool myTransparentPixelFound = false;
116 TransparentThreeValuePixel myTransparentPixel = {0, 0, 0, 100};
117 for ( int myListRunner = 0; myListRunner < mTransparentThreeValuePixelList.count(); myListRunner++ )
118 {
119 myTransparentPixel = mTransparentThreeValuePixelList[myListRunner];
120 if ( qgsDoubleNear( myTransparentPixel.red, redValue ) )
121 {
122 if ( qgsDoubleNear( myTransparentPixel.green, greenValue ) )
123 {
124 if ( qgsDoubleNear( myTransparentPixel.blue, blueValue ) )
125 {
126 myTransparentPixelFound = true;
127 break;
128 }
129 }
130 }
131 }
132
133 //if a match was found use the stored transparency percentage
134 if ( myTransparentPixelFound )
135 {
136 return static_cast< int >( static_cast< float >( globalTransparency ) * ( 1.0 - ( myTransparentPixel.percentTransparent / 100.0 ) ) );
137 }
138
139 return globalTransparency;
140}
141
143{
144 return mTransparentSingleValuePixelList.isEmpty() && mTransparentThreeValuePixelList.isEmpty();
145}
146
147void QgsRasterTransparency::writeXml( QDomDocument &doc, QDomElement &parentElem ) const
148{
149 QDomElement rasterTransparencyElem = doc.createElement( QStringLiteral( "rasterTransparency" ) );
150 if ( !mTransparentSingleValuePixelList.isEmpty() )
151 {
152 QDomElement singleValuePixelListElement = doc.createElement( QStringLiteral( "singleValuePixelList" ) );
153 QList<QgsRasterTransparency::TransparentSingleValuePixel>::const_iterator it = mTransparentSingleValuePixelList.constBegin();
154 for ( ; it != mTransparentSingleValuePixelList.constEnd(); ++it )
155 {
156 QDomElement pixelListElement = doc.createElement( QStringLiteral( "pixelListEntry" ) );
157 pixelListElement.setAttribute( QStringLiteral( "min" ), QgsRasterBlock::printValue( it->min ) );
158 pixelListElement.setAttribute( QStringLiteral( "max" ), QgsRasterBlock::printValue( it->max ) );
159 pixelListElement.setAttribute( QStringLiteral( "percentTransparent" ), QString::number( it->percentTransparent ) );
160 singleValuePixelListElement.appendChild( pixelListElement );
161 }
162 rasterTransparencyElem.appendChild( singleValuePixelListElement );
163
164 }
165 if ( !mTransparentThreeValuePixelList.isEmpty() )
166 {
167 QDomElement threeValuePixelListElement = doc.createElement( QStringLiteral( "threeValuePixelList" ) );
168 QList<QgsRasterTransparency::TransparentThreeValuePixel>::const_iterator it = mTransparentThreeValuePixelList.constBegin();
169 for ( ; it != mTransparentThreeValuePixelList.constEnd(); ++it )
170 {
171 QDomElement pixelListElement = doc.createElement( QStringLiteral( "pixelListEntry" ) );
172 pixelListElement.setAttribute( QStringLiteral( "red" ), QgsRasterBlock::printValue( it->red ) );
173 pixelListElement.setAttribute( QStringLiteral( "green" ), QgsRasterBlock::printValue( it->green ) );
174 pixelListElement.setAttribute( QStringLiteral( "blue" ), QgsRasterBlock::printValue( it->blue ) );
175 pixelListElement.setAttribute( QStringLiteral( "percentTransparent" ), QString::number( it->percentTransparent ) );
176 threeValuePixelListElement.appendChild( pixelListElement );
177 }
178 rasterTransparencyElem.appendChild( threeValuePixelListElement );
179 }
180 parentElem.appendChild( rasterTransparencyElem );
181}
182
183void QgsRasterTransparency::readXml( const QDomElement &elem )
184{
185 if ( elem.isNull() )
186 {
187 return;
188 }
189
190 mTransparentSingleValuePixelList.clear();
191 mTransparentThreeValuePixelList.clear();
192 QDomElement currentEntryElem;
193
194 const QDomElement singlePixelListElem = elem.firstChildElement( QStringLiteral( "singleValuePixelList" ) );
195 if ( !singlePixelListElem.isNull() )
196 {
197 const QDomNodeList entryList = singlePixelListElem.elementsByTagName( QStringLiteral( "pixelListEntry" ) );
199 for ( int i = 0; i < entryList.size(); ++i )
200 {
201 currentEntryElem = entryList.at( i ).toElement();
202 sp.percentTransparent = currentEntryElem.attribute( QStringLiteral( "percentTransparent" ) ).toDouble();
203 // Backward compoatibility < 1.9 : pixelValue (before ranges)
204 if ( currentEntryElem.hasAttribute( QStringLiteral( "pixelValue" ) ) )
205 {
206 sp.min = sp.max = currentEntryElem.attribute( QStringLiteral( "pixelValue" ) ).toDouble();
207 }
208 else
209 {
210 sp.min = currentEntryElem.attribute( QStringLiteral( "min" ) ).toDouble();
211 sp.max = currentEntryElem.attribute( QStringLiteral( "max" ) ).toDouble();
212 }
213 mTransparentSingleValuePixelList.append( sp );
214 }
215 }
216 const QDomElement threeValuePixelListElem = elem.firstChildElement( QStringLiteral( "threeValuePixelList" ) );
217 if ( !threeValuePixelListElem.isNull() )
218 {
219 const QDomNodeList entryList = threeValuePixelListElem.elementsByTagName( QStringLiteral( "pixelListEntry" ) );
221 for ( int i = 0; i < entryList.size(); ++i )
222 {
223 currentEntryElem = entryList.at( i ).toElement();
224 tp.red = currentEntryElem.attribute( QStringLiteral( "red" ) ).toDouble();
225 tp.green = currentEntryElem.attribute( QStringLiteral( "green" ) ).toDouble();
226 tp.blue = currentEntryElem.attribute( QStringLiteral( "blue" ) ).toDouble();
227 tp.percentTransparent = currentEntryElem.attribute( QStringLiteral( "percentTransparent" ) ).toDouble();
228 mTransparentThreeValuePixelList.append( tp );
229 }
230 }
231}
static QString printValue(double value)
Print double value with all necessary significant digits.
void setTransparentSingleValuePixelList(const QList< QgsRasterTransparency::TransparentSingleValuePixel > &newList)
Sets the transparent single value pixel list, replacing the whole existing list.
QList< QgsRasterTransparency::TransparentThreeValuePixel > transparentThreeValuePixelList() const
Returns the transparent three value pixel list.
void setTransparentThreeValuePixelList(const QList< QgsRasterTransparency::TransparentThreeValuePixel > &newList)
Sets the transparent three value pixel list, replacing the whole existing list.
int alphaValue(double value, int globalTransparency=255) const
Returns the transparency value for a single value pixel.
void initializeTransparentPixelList(double value)
Resets the transparency list to a single value.
void writeXml(QDomDocument &doc, QDomElement &parentElem) const
Writes the transparency information to an XML document.
QList< QgsRasterTransparency::TransparentSingleValuePixel > transparentSingleValuePixelList() const
Returns the transparent single value pixel list.
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.
bool qgsDoubleNear(double a, double b, double epsilon=4 *std::numeric_limits< double >::epsilon())
Compare two doubles (but allow some difference)
Definition: qgis.h:2404