View in QML C++ View on GitHub Sample viewer app
Apply a raster function to a local raster file and display the output with a raster layer.
Use case
Raster functions allow processing operations that can be applied to one or more rasters on the fly. A land survey agency may apply hillshade and aspect functions to rasters with elevation data in order to better determine the topography of a landscape and to make further planning decisions.
How to use the sample
Load the sample to see a raster function applied to a raster.
How it works
Create a RasterFunction
using the path to a local raster function JSON file.
Set the raster function arguments as required by the function used.
Use the raster function to create a new Raster
.
Set the raster to a RasterLayer
and display it in the Map
.
Relevant API
Raster
RasterFunction
RasterLayer
Offline Data
Read more about how to set up the sample's offline data here .
About the data
The raster function in the provided JSON file blends a color image with a greyscale image (in this case, a raster image containing elevation data), to add a hillshade effect to the input raster.
Learn more about raster functions in the ArcGIS Pro documentation.
analysis, function, image, layer, processing, raster, raster function, transformation
Sample CodeRasterFunctionFile.cpp RasterFunctionFile.cpp RasterFunctionFile.h RasterFunctionFile.qml
Use dark colors for code blocks Copy
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
// [WriteFile Name=RasterFunctionFile, Category=Layers]
// [Legal]
// Copyright 2017 Esri.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// [Legal]
# ifdef PCH_BUILD
# include "pch.hpp"
# endif // PCH_BUILD
# include "RasterFunctionFile.h"
# include "Map.h"
# include "MapQuickView.h"
# include "Basemap.h"
# include "Raster.h"
# include "RasterLayer.h"
# include "RasterFunction.h"
# include "Envelope.h"
# include "MapTypes.h"
# include "Error.h"
# include "LayerListModel.h"
# include "RasterFunctionArguments.h"
# include "Viewpoint.h"
# include <QFileInfo>
# include <QtCore/qglobal.h>
# include <QStandardPaths>
using namespace Esri::ArcGISRuntime;
// helper method to get cross platform data path
namespace
{
QString defaultDataPath ()
{
QString dataPath;
# ifdef Q_OS_IOS
dataPath = QStandardPaths:: writableLocation (QStandardPaths::DocumentsLocation);
# else
dataPath = QStandardPaths:: writableLocation (QStandardPaths::HomeLocation);
# endif
return dataPath;
}
} // namespace
RasterFunctionFile:: RasterFunctionFile (QQuickItem* parent /* = nullptr */ ):
QQuickItem (parent),
m_dataPath ( defaultDataPath () + "/ArcGIS/Runtime/Data/raster/" )
{
}
void RasterFunctionFile::init ()
{
// Register the map view for QML
qmlRegisterType<MapQuickView>( "Esri.Samples" , 1 , 0 , "MapView" );
qmlRegisterType<RasterFunctionFile>( "Esri.Samples" , 1 , 0 , "RasterFunctionFileSample" );
}
void RasterFunctionFile::componentComplete ()
{
QQuickItem:: componentComplete ();
// get data path
m_rasterPath = m_dataPath + "Shasta_Elevation.tif" ;
// find QML MapView component
m_mapView = findChild<MapQuickView*>( "mapView" );
// Create a map using the imagery basemap
m_map = new Map (BasemapStyle::ArcGISImageryStandard, this );
// Add the Raster Layer
m_raster = new Raster (m_rasterPath, this );
RasterLayer* rasterLayer = new RasterLayer (m_raster, this );
rasterLayer-> setOpacity ( 0.5 );
connect (rasterLayer, &RasterLayer::doneLoading, this , &RasterFunctionFile::readyChanged);
m_map-> operationalLayers ()-> append (rasterLayer);
// Set initial Extent
Envelope env = geometry_cast<Envelope>(Envelope:: fromJson ( "{\"spatialReference\": {\"latestWkid\": 3857, \"wkid\": 102100 },\"xmax\": -13591503.517810356,\"xmin\": -13606233.44023646,\"ymax\": 4982810.138527592,\"ymin\": 4971762.696708013}" ));
m_map-> setInitialViewpoint ( Viewpoint (env));
// Set map to map view
m_mapView-> setMap (m_map);
}
void RasterFunctionFile::applyRasterFunction ()
{
// create raster function
RasterFunction* rasterFunction = createRasterFunction ();
// check for valid raster function
if (!rasterFunction)
return ;
// create the raster from the raster function
Raster* raster = new Raster (rasterFunction, this );
// create raster layer from raster
RasterLayer* rasterLayer = new RasterLayer (raster, this );
rasterLayer-> setOpacity ( 0.5 );
// add raster to map
m_map-> operationalLayers ()-> clear ();
m_map-> operationalLayers ()-> append (rasterLayer);
}
RasterFunction* RasterFunctionFile::createRasterFunction ()
{
// Check if the raster function json exists
QFileInfo colorJson (m_dataPath + "/color.json" ) ;
if (!colorJson. exists ())
return nullptr ;
// create a RasterFunction
RasterFunction* rasterFunction = new RasterFunction (m_dataPath + "/color.json" , this );
// check for valid raster function
if (!rasterFunction)
return nullptr ;
// set the number of rasters required - 2 in this case
rasterFunction-> arguments ()-> setRaster ( "raster" , m_raster);
rasterFunction-> arguments ()-> setRaster ( "raster" , m_raster);
return rasterFunction;
}
bool RasterFunctionFile::ready () const
{
return m_raster && m_raster-> loadStatus () == LoadStatus::Loaded;
}