QGIS API Documentation 3.27.0-Master (75dc696944)
qgspointcloudattributebyramprenderer.cpp
Go to the documentation of this file.
1/***************************************************************************
2 qgspointcloudattributebyramprenderer.h
3 --------------------
4 begin : October 2020
5 copyright : (C) 2020 by Nyall Dawson
6 email : nyall dot dawson 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
19#include "qgspointcloudblock.h"
20#include "qgsstyle.h"
21#include "qgscolorramp.h"
22#include "qgssymbollayerutils.h"
25
27{
28 mColorRampShader.setSourceColorRamp( QgsStyle::defaultStyle()->colorRamp( QStringLiteral( "Viridis" ) ) );
29 mColorRampShader.classifyColorRamp( 5, -1, QgsRectangle(), nullptr );
30}
31
33{
34 return QStringLiteral( "ramp" );
35}
36
38{
39 std::unique_ptr< QgsPointCloudAttributeByRampRenderer > res = std::make_unique< QgsPointCloudAttributeByRampRenderer >();
40 res->mAttribute = mAttribute;
41 res->mColorRampShader = mColorRampShader;
42 res->mMin = mMin;
43 res->mMax = mMax;
44
45 copyCommonProperties( res.get() );
46
47 return res.release();
48}
49
51{
52 const QgsRectangle visibleExtent = context.renderContext().extent();
53
54 const char *ptr = block->data();
55 int count = block->pointCount();
56 const QgsPointCloudAttributeCollection request = block->attributes();
57
58 const std::size_t recordSize = request.pointRecordSize();
59 int attributeOffset = 0;
60 const QgsPointCloudAttribute *attribute = request.find( mAttribute, attributeOffset );
61 if ( !attribute )
62 return;
63 const QgsPointCloudAttribute::DataType attributeType = attribute->type();
64
65 const QgsDoubleRange zRange = context.renderContext().zRange();
66 const bool considerZ = !zRange.isInfinite();
67
68 const bool applyZOffset = attribute->name() == QLatin1String( "Z" );
69 const bool applyXOffset = attribute->name() == QLatin1String( "X" );
70 const bool applyYOffset = attribute->name() == QLatin1String( "Y" );
71
72 int rendered = 0;
73 double x = 0;
74 double y = 0;
75 double z = 0;
77 const bool reproject = ct.isValid();
78
79 int red = 0;
80 int green = 0;
81 int blue = 0;
82 int alpha = 0;
83 for ( int i = 0; i < count; ++i )
84 {
85 if ( context.renderContext().renderingStopped() )
86 {
87 break;
88 }
89
90 if ( considerZ )
91 {
92 // z value filtering is cheapest, if we're doing it...
93 z = pointZ( context, ptr, i );
94 if ( !zRange.contains( z ) )
95 continue;
96 }
97
98 pointXY( context, ptr, i, x, y );
99 if ( visibleExtent.contains( x, y ) )
100 {
101 if ( reproject )
102 {
103 try
104 {
105 ct.transformInPlace( x, y, z );
106 }
107 catch ( QgsCsException & )
108 {
109 continue;
110 }
111 }
112
113 double attributeValue = 0;
114 context.getAttribute( ptr, i * recordSize + attributeOffset, attributeType, attributeValue );
115
116 if ( applyXOffset )
117 attributeValue = context.offset().x() + context.scale().x() * attributeValue;
118 if ( applyYOffset )
119 attributeValue = context.offset().y() + context.scale().y() * attributeValue;
120 if ( applyZOffset )
121 attributeValue = ( context.offset().z() + context.scale().z() * attributeValue ) * context.zValueScale() + context.zValueFixedOffset();
122
123 mColorRampShader.shade( attributeValue, &red, &green, &blue, &alpha );
124 drawPoint( x, y, QColor( red, green, blue, alpha ), context );
125
126 rendered++;
127 }
128 }
129 context.incrementPointsRendered( rendered );
130}
131
132
134{
135 std::unique_ptr< QgsPointCloudAttributeByRampRenderer > r = std::make_unique< QgsPointCloudAttributeByRampRenderer >();
136
137 r->setAttribute( element.attribute( QStringLiteral( "attribute" ), QStringLiteral( "Intensity" ) ) );
138
139 QDomElement elemShader = element.firstChildElement( QStringLiteral( "colorrampshader" ) );
140 r->mColorRampShader.readXml( elemShader, context );
141
142 r->setMinimum( element.attribute( QStringLiteral( "min" ), QStringLiteral( "0" ) ).toDouble() );
143 r->setMaximum( element.attribute( QStringLiteral( "max" ), QStringLiteral( "100" ) ).toDouble() );
144
145 r->restoreCommonProperties( element, context );
146
147 return r.release();
148}
149
150QDomElement QgsPointCloudAttributeByRampRenderer::save( QDomDocument &doc, const QgsReadWriteContext &context ) const
151{
152 QDomElement rendererElem = doc.createElement( QStringLiteral( "renderer" ) );
153
154 rendererElem.setAttribute( QStringLiteral( "type" ), QStringLiteral( "ramp" ) );
155 rendererElem.setAttribute( QStringLiteral( "min" ), mMin );
156 rendererElem.setAttribute( QStringLiteral( "max" ), mMax );
157
158 rendererElem.setAttribute( QStringLiteral( "attribute" ), mAttribute );
159
160 QDomElement elemShader = mColorRampShader.writeXml( doc, context );
161 rendererElem.appendChild( elemShader );
162
163 saveCommonProperties( rendererElem, context );
164
165 return rendererElem;
166}
167
169{
170 QSet<QString> res;
171 res << mAttribute;
172 return res;
173}
174
175QList<QgsLayerTreeModelLegendNode *> QgsPointCloudAttributeByRampRenderer::createLegendNodes( QgsLayerTreeLayer *nodeLayer )
176{
177 QList<QgsLayerTreeModelLegendNode *> res;
178 res << new QgsSimpleLegendNode( nodeLayer, mAttribute );
179
180 switch ( mColorRampShader.colorRampType() )
181 {
183 // for interpolated shaders we use a ramp legend node unless the settings flag
184 // to use the continuous legend is not set, in that case we fall through
185 if ( mColorRampShader.sourceColorRamp() && ( ! mColorRampShader.legendSettings() || mColorRampShader.legendSettings()->useContinuousLegend() ) )
186 {
187 res << new QgsColorRampLegendNode( nodeLayer, mColorRampShader.sourceColorRamp()->clone(),
188 mColorRampShader.legendSettings() ? *mColorRampShader.legendSettings() : QgsColorRampLegendNodeSettings(),
189 mColorRampShader.minimumValue(),
190 mColorRampShader.maximumValue() );
191 break;
192 }
193 Q_FALLTHROUGH();
196 {
197 // for all others we use itemised lists
198 QList< QPair< QString, QColor > > items;
199 mColorRampShader.legendSymbologyItems( items );
200 res.reserve( items.size() );
201 for ( const QPair< QString, QColor > &item : std::as_const( items ) )
202 {
203 res << new QgsRasterSymbolLegendNode( nodeLayer, item.second, item.first );
204 }
205 break;
206 }
207 }
208 return res;
209}
210
212{
213 return mAttribute;
214}
215
217{
218 mAttribute = attribute;
219}
220
222{
223 return mColorRampShader;
224}
225
227{
228 mColorRampShader = shader;
229}
230
232{
233 return mMin;
234}
235
237{
238 mMin = minimum;
239}
240
242{
243 return mMax;
244}
245
247{
248 mMax = value;
249}
250
251std::unique_ptr<QgsPreparedPointCloudRendererData> QgsPointCloudAttributeByRampRenderer::prepare()
252{
253 std::unique_ptr< QgsPointCloudAttributeByRampRendererPreparedData> data = std::make_unique< QgsPointCloudAttributeByRampRendererPreparedData >();
254 data->attributeName = mAttribute;
255 data->colorRampShader = mColorRampShader;
256
257 data->attributeIsX = mAttribute == QLatin1String( "X" );
258 data->attributeIsY = mAttribute == QLatin1String( "Y" );
259 data->attributeIsZ = mAttribute == QLatin1String( "Z" );
260 return data;
261}
262
264{
265 double attributeValue = 0;
266 if ( attributeIsZ )
267 attributeValue = z;
268 else
270
271 if ( attributeIsX )
272 attributeValue = block->offset().x() + block->scale().x() * attributeValue;
273 else if ( attributeIsY )
274 attributeValue = block->offset().y() + block->scale().y() * attributeValue;
275
276 int red = 0;
277 int green = 0;
278 int blue = 0;
279 int alpha = 0;
280 colorRampShader.shade( attributeValue, &red, &green, &blue, &alpha );
281 return QColor( red, green, blue, alpha );
282}
283
285{
286 return { attributeName };
287}
288
290{
291 const QgsPointCloudAttributeCollection attributes = block->attributes();
292 const QgsPointCloudAttribute *attribute = attributes.find( attributeName, attributeOffset );
293 if ( !attribute )
294 return false;
295
296 attributeType = attribute->type();
297 return true;
298}
Settings for a color ramp legend node.
bool useContinuousLegend() const
Returns true if a continuous gradient legend will be used.
A legend node which renders a color ramp.
A ramp shader will color a raster pixel based on a list of values ranges in a ramp.
void legendSymbologyItems(QList< QPair< QString, QColor > > &symbolItems) const override
Returns legend symbology items if provided by renderer.
const QgsColorRampLegendNodeSettings * legendSettings() const
Returns the color ramp shader legend settings.
Type colorRampType() const
Returns the color ramp type.
void setSourceColorRamp(QgsColorRamp *colorramp)
Set the source color ramp.
QDomElement writeXml(QDomDocument &doc, const QgsReadWriteContext &context=QgsReadWriteContext()) const
Writes configuration to a new DOM element.
bool shade(double value, int *returnRedValue, int *returnGreenValue, int *returnBlueValue, int *returnAlphaValue) const override
Generates and new RGB value based on one input value.
QgsColorRamp * sourceColorRamp() const
Returns the source color ramp.
@ Interpolated
Interpolates the color between two class breaks linearly.
@ Discrete
Assigns the color of the higher class for every pixel between two class breaks.
@ Exact
Assigns the color of the exact matching value in the color ramp item list.
void classifyColorRamp(int classes=0, int band=-1, const QgsRectangle &extent=QgsRectangle(), QgsRasterInterface *input=nullptr)
Classify color ramp shader.
virtual QgsColorRamp * clone() const =0
Creates a clone of the color ramp.
Class for doing transforms between two map coordinate systems.
bool isValid() const
Returns true if the coordinate transform is valid, ie both the source and destination CRS have been s...
void transformInPlace(double &x, double &y, double &z, Qgis::TransformDirection direction=Qgis::TransformDirection::Forward) const SIP_THROW(QgsCsException)
Transforms an array of x, y and z double coordinates in place, from the source CRS to the destination...
Custom exception class for Coordinate Reference System related exceptions.
Definition: qgsexception.h:66
QgsRange which stores a range of double values.
Definition: qgsrange.h:203
bool isInfinite() const
Returns true if the range consists of all possible values.
Definition: qgsrange.h:247
Layer tree node points to a map layer.
QColor pointColor(const QgsPointCloudBlock *block, int i, double z) override
An optimised method of retrieving the color of a point from a point cloud block.
bool prepareBlock(const QgsPointCloudBlock *block) override
Prepares the renderer for using the specified block.
QSet< QString > usedAttributes() const override
Returns the set of attributes used by the prepared point cloud renderer.
QString type() const override
Returns the identifier of the renderer type.
void setMaximum(double maximum)
Sets the maximum value for attributes which will be used by the color ramp shader.
QgsPointCloudRenderer * clone() const override
Create a deep copy of this renderer.
static QgsPointCloudRenderer * create(QDomElement &element, const QgsReadWriteContext &context)
Creates an RGB renderer from an XML element.
void renderBlock(const QgsPointCloudBlock *block, QgsPointCloudRenderContext &context) override
Renders a block of point cloud data using the specified render context.
void setMinimum(double minimum)
Sets the minimum value for attributes which will be used by the color ramp shader.
QgsPointCloudAttributeByRampRenderer()
Constructor for QgsPointCloudAttributeByRampRenderer.
QDomElement save(QDomDocument &doc, const QgsReadWriteContext &context) const override
Saves the renderer configuration to an XML element.
double maximum() const
Returns the maximum value for attributes which will be used by the color ramp shader.
QList< QgsLayerTreeModelLegendNode * > createLegendNodes(QgsLayerTreeLayer *nodeLayer) override
Creates a set of legend nodes representing the renderer.
void setColorRampShader(const QgsColorRampShader &shader)
Sets the color ramp shader function used to visualize the attribute.
QSet< QString > usedAttributes(const QgsPointCloudRenderContext &context) const override
Returns a list of attributes required by this renderer.
std::unique_ptr< QgsPreparedPointCloudRendererData > prepare() override
Returns prepared data container for bulk point color retrieval.
QgsColorRampShader colorRampShader() const
Returns the color ramp shader function used to visualize the attribute.
double minimum() const
Returns the minimum value for attributes which will be used by the color ramp shader.
QString attribute() const
Returns the attribute to use for the renderer.
void setAttribute(const QString &attribute)
Sets the attribute to use for the renderer.
Collection of point cloud attributes.
int pointRecordSize() const
Returns total size of record.
const QgsPointCloudAttribute * find(const QString &attributeName, int &offset) const
Finds the attribute with the name.
Attribute for point cloud data pair of name and size in bytes.
DataType
Systems of unit measurement.
DataType type() const
Returns the data type.
Base class for storing raw data from point cloud nodes.
QgsVector3D scale() const
Returns the custom scale of the block.
const char * data() const
Returns raw pointer to data.
QgsPointCloudAttributeCollection attributes() const
Returns the attributes that are stored in the data block, along with their size.
int pointCount() const
Returns number of points that are stored in the block.
int pointRecordSize() const
Returns the total size of each individual point record.
QgsVector3D offset() const
Returns the custom offset of the block.
Encapsulates the render context for a 2D point cloud rendering operation.
double zValueFixedOffset() const
Returns any constant offset which must be applied to z values taken from the point cloud index.
QgsVector3D offset() const
Returns the offset of the layer's int32 coordinates compared to CRS coords.
QgsRenderContext & renderContext()
Returns a reference to the context's render context.
void incrementPointsRendered(long count)
Increments the count of points rendered by the specified amount.
static void getAttribute(const char *data, std::size_t offset, QgsPointCloudAttribute::DataType type, T &value)
Retrieves the attribute value from data at the specified offset, where type indicates the original da...
double zValueScale() const
Returns any constant scaling factor which must be applied to z values taken from the point cloud inde...
QgsVector3D scale() const
Returns the scale of the layer's int32 coordinates compared to CRS coords.
Abstract base class for 2d point cloud renderers.
void saveCommonProperties(QDomElement &element, const QgsReadWriteContext &context) const
Saves common renderer properties (such as point size and screen error) to the specified DOM element.
void copyCommonProperties(QgsPointCloudRenderer *destination) const
Copies common point cloud properties (such as point size and screen error) to the destination rendere...
void drawPoint(double x, double y, const QColor &color, QgsPointCloudRenderContext &context) const
Draws a point using a color at the specified x and y (in map coordinates).
static double pointZ(QgsPointCloudRenderContext &context, const char *ptr, int i)
Retrieves the z value for the point at index i.
static void pointXY(QgsPointCloudRenderContext &context, const char *ptr, int i, double &x, double &y)
Retrieves the x and y coordinate for the point at index i.
bool contains(const QgsRange< T > &other) const
Returns true if this range contains another range.
Definition: qgsrange.h:108
double maximumValue() const
Returns the minimum value for the raster shader.
double minimumValue() const
Returns the maximum value for the raster shader.
Implementation of legend node interface for displaying raster legend entries.
The class is used as a container of context for various read/write operations on other objects.
A rectangle specified with double values.
Definition: qgsrectangle.h:42
bool contains(const QgsRectangle &rect) const SIP_HOLDGIL
Returns true when rectangle contains other rectangle.
Definition: qgsrectangle.h:363
const QgsRectangle & extent() const
When rendering a map layer, calling this method returns the "clipping" extent for the layer (in the l...
QgsDoubleRange zRange() const
Returns the range of z-values which should be rendered.
bool renderingStopped() const
Returns true if the rendering operation has been stopped and any ongoing rendering should be canceled...
QgsCoordinateTransform coordinateTransform() const
Returns the current coordinate transform for the context.
Implementation of legend node interface for displaying arbitrary label with icon.
static QgsStyle * defaultStyle()
Returns default application-wide style.
Definition: qgsstyle.cpp:145
double y() const
Returns Y coordinate.
Definition: qgsvector3d.h:51
double z() const
Returns Z coordinate.
Definition: qgsvector3d.h:53
double x() const
Returns X coordinate.
Definition: qgsvector3d.h:49