QGIS API Documentation 3.39.0-Master (699c004a5df)
Loading...
Searching...
No Matches
qgsmapsettingsutils.cpp
Go to the documentation of this file.
1/***************************************************************************
2 qgsmapsettingsutils.cpp
3 -------------------
4 begin : May 2017
5 copyright : (C) 2017 by Mathieu Pellerin
6 email : nirvn dot asia at gmail dot 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 "qgsmapsettings.h"
19#include "qgsmapsettingsutils.h"
20#include "qgspallabeling.h"
21#include "qgstextformat.h"
22#include "qgsvectorlayer.h"
24
25#include <QString>
26
28{
29 QSet< QString > layers;
30
31 QgsTextFormat layerFormat;
32 const auto constLayers = mapSettings.layers();
33 for ( QgsMapLayer *layer : constLayers )
34 {
35 if ( layer && layer->isInScaleRange( mapSettings.scale() ) )
36 {
37 bool layerHasAdvancedBlendMode = false;
38 if ( layer->blendMode() != QPainter::CompositionMode_SourceOver )
39 {
41 {
42 layerHasAdvancedBlendMode = !QgsAbstractGeoPdfExporter::compositionModeSupported( layer->blendMode() );
43 }
44 else
45 {
46 layerHasAdvancedBlendMode = true;
47 }
48 }
49
50 if ( layerHasAdvancedBlendMode )
51 {
52 layers << layer->name();
53 }
54 // if vector layer, check labels and feature blend mode
55 if ( QgsVectorLayer *currentVectorLayer = qobject_cast<QgsVectorLayer *>( layer ) )
56 {
57 if ( currentVectorLayer->featureBlendMode() != QPainter::CompositionMode_SourceOver )
58 {
59 layers << layer->name();
60 }
61 // check label blend modes
62 if ( QgsPalLabeling::staticWillUseLayer( currentVectorLayer ) )
63 {
64 // Check all label blending properties
65 layerFormat.readFromLayer( currentVectorLayer );
66 if ( layerFormat.containsAdvancedEffects() )
67 {
68 layers << layer->name();
69 }
70 }
71 }
72 }
73 }
74
75 return QStringList( layers.constBegin(), layers.constEnd() );
76}
77
78void QgsMapSettingsUtils::worldFileParameters( const QgsMapSettings &mapSettings, double &a, double &b, double &c, double &d, double &e, double &f )
79{
80 QgsMapSettings ms = mapSettings;
81
82 const double rotation = ms.rotation();
83 const double alpha = rotation / 180 * M_PI;
84
85 // reset rotation to 0 to calculate world file parameters
86 ms.setRotation( 0 );
87
88 const double xOrigin = ms.visibleExtent().xMinimum() + ( ms.mapUnitsPerPixel() / 2 );
89 const double yOrigin = ms.visibleExtent().yMaximum() - ( ms.mapUnitsPerPixel() / 2 );
90
91 const double xCenter = ms.visibleExtent().center().x();
92 const double yCenter = ms.visibleExtent().center().y();
93
94 // scaling matrix
95 double s[6];
96 s[0] = ms.mapUnitsPerPixel() / ms.devicePixelRatio();
97 s[1] = 0;
98 s[2] = xOrigin;
99 s[3] = 0;
100 s[4] = -ms.mapUnitsPerPixel() / ms.devicePixelRatio();
101 s[5] = yOrigin;
102
103 // rotation matrix
104 double r[6];
105 r[0] = std::cos( alpha );
106 r[1] = -std::sin( alpha );
107 r[2] = xCenter * ( 1 - std::cos( alpha ) ) + yCenter * std::sin( alpha );
108 r[3] = std::sin( alpha );
109 r[4] = std::cos( alpha );
110 r[5] = - xCenter * std::sin( alpha ) + yCenter * ( 1 - std::cos( alpha ) );
111
112 // result = rotation x scaling = rotation(scaling(X))
113 a = r[0] * s[0] + r[1] * s[3];
114 b = r[0] * s[1] + r[1] * s[4];
115 c = r[0] * s[2] + r[1] * s[5] + r[2];
116 d = r[3] * s[0] + r[4] * s[3];
117 // Pixel YDim - almost always negative
118 // See https://en.wikipedia.org/wiki/World_file#cite_ref-3, https://github.com/qgis/QGIS/issues/26379
119 e = r[3] * s[1] + r[4] * s[4];
120 f = r[3] * s[2] + r[4] * s[5] + r[5];
121}
122
124{
125 double a, b, c, d, e, f;
126 worldFileParameters( mapSettings, a, b, c, d, e, f );
127
128 QString content;
129 // Pixel XDim
130 content += qgsDoubleToString( a ) + "\r\n";
131 // Rotation on y axis
132 content += qgsDoubleToString( d ) + "\r\n";
133 // Rotation on x axis
134 content += qgsDoubleToString( b ) + "\r\n";
135 // Pixel YDim
136 content += qgsDoubleToString( e ) + "\r\n";
137 // Origin X (top left cell)
138 content += qgsDoubleToString( c ) + "\r\n";
139 // Origin Y (top left cell)
140 content += qgsDoubleToString( f ) + "\r\n";
141
142 return content;
143}
static bool compositionModeSupported(QPainter::CompositionMode mode)
Returns true if the specified composition mode is supported for layers during GeoPDF exports.
Base class for all map layer types.
Definition qgsmaplayer.h:76
@ IgnoreGeoPdfSupportedEffects
Ignore advanced effects which are supported in GeoPDF exports.
QFlags< EffectsCheckFlag > EffectsCheckFlags
static void worldFileParameters(const QgsMapSettings &mapSettings, double &a, double &b, double &c, double &d, double &e, double &f)
Computes the six parameters of a world file.
static QStringList containsAdvancedEffects(const QgsMapSettings &mapSettings, EffectsCheckFlags flags=QgsMapSettingsUtils::EffectsCheckFlags())
Checks whether any of the layers attached to a map settings object contain advanced effects.
static QString worldFileContent(const QgsMapSettings &mapSettings)
Creates the content of a world file.
The QgsMapSettings class contains configuration for rendering of the map.
QList< QgsMapLayer * > layers(bool expandGroupLayers=false) const
Returns the list of layers which will be rendered in the map.
double scale() const
Returns the calculated map scale.
double mapUnitsPerPixel() const
Returns the distance in geographical coordinates that equals to one pixel in the map.
float devicePixelRatio() const
Returns the device pixel ratio.
QgsRectangle visibleExtent() const
Returns the actual extent derived from requested extent that takes output image size into account.
void setRotation(double rotation)
Sets the rotation of the resulting map image, in degrees clockwise.
double rotation() const
Returns the rotation of the resulting map image, in degrees clockwise.
static bool staticWillUseLayer(const QgsMapLayer *layer)
Called to find out whether a specified layer is used for labeling.
double y
Definition qgspointxy.h:64
double x
Definition qgspointxy.h:63
double xMinimum() const
Returns the x minimum value (left side of rectangle).
double yMaximum() const
Returns the y maximum value (top side of rectangle).
QgsPointXY center() const
Returns the center point of the rectangle.
Container for all settings relating to text rendering.
void readFromLayer(QgsVectorLayer *layer)
Reads settings from a layer's custom properties (for QGIS 2.x projects).
bool containsAdvancedEffects() const
Returns true if any component of the font format requires advanced effects such as blend modes,...
Represents a vector layer which manages a vector based data sets.
As part of the API refactoring and improvements which landed in the Processing API was substantially reworked from the x version This was done in order to allow much of the underlying Processing framework to be ported into c
QString qgsDoubleToString(double a, int precision=17)
Returns a string representation of a double.
Definition qgis.h:5798