An object-oriented programming language

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0answers
11 views

raster doesn't redraw to fit the canvas after a zoom in and a pan

i am working with qgis 2.8.2, c++ api and qt 4.8.5 i have a layer in the mapcanvas, this layer contains a raster ( a georef tif picture ) when i zoom in, the raster fill the entire canvas , ok but if ...
1
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0answers
10 views

pinchZoom with qgis 2.82 and qt

I am working with qgis 2.8.2 c++ api and qt4.8.5 in my project i had to implement the pinchzoom because i use a 27" touch screen i am looking for information on how to use the qgis lib with the qt ...
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0answers
6 views

OSM map tiles offline view [duplicate]

How can I view openstreetmap tiles offline using c++? I need to integrate osm tiles viewer (view tiles, zoom etc.) offline on c++.
1
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4answers
46 views

OSM tiles offline display using c++

I have openstreetmap tiles for offline (png images), how can I display these images (tiles) on my application with zooming and rotation functionality as on openstreetmap.org using c++?
3
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2answers
38 views

Converting Python GDALDataset to C++ GDALDataset

I'm currently writing a C++ extension to python to speed up a raster data viewer which is running extremely slowly with our large datasets. I've managed to get a small speedup by writing a C++ ...
2
votes
1answer
48 views

Fastest way to process OSM

I've been working with imposm and Python, it's fairly easy to parallelise. I've hit a performance problem when trying to associate the coordinates to the ways. Creating a dictionary from ...
1
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0answers
20 views

Changing Dataset Property

I 'm working on GDAL C++. But I have some trouble to change GDALDataset property. I have converted "jpg" to "bmp" an image. But I want to do read an image(jpg) to gdaldataset then change dataset ...
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0answers
25 views

Using GDAL in C++. Create multiple GDALDatasets using a GDALDriver produces error 4 not recognised as a supported file format [closed]

I am trying to create multiple GDALDataset objects. All of them are supposed to be in the .tif format, so for all of them I use the same GDALDriver. I am working in C++ (Visual Studio) and when I ...
3
votes
1answer
17 views

Help with Meters at Lat calculation accuracy, two methods

So I'm coding a program (c++), and thing leads to thing, and I need to find out how many meters to a degree of longitude at a specific latitude to a very high precision. Optimally < 1 meter at all ...
1
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1answer
26 views

QGIS not opening after update

I installed/updated microsoft visual c++ 2013 and microsoft directX runtime 2013. After that, whenever i open qgis i get this The program can't start because MSVCP120.dll is missing from your ...
1
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1answer
52 views

GDAL/OGR in C++: Merge multiple vector datasets to single [closed]

I need to merge multiple kml files into a single one. I found that I could use "ogr2ogr -append" but I have to do it through c++ and my Google-fu hasn't been successful so far. So, any ideas? Also, ...
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0answers
41 views

I want to make a small TIFF file from a big TIFF file

I just study on GIS system. When I create the Tiff file, there is no any data in Tiff file I want to make 4 channel TIFF file My code is below: void crop(const char *inputPath, const char ...
2
votes
1answer
14 views

the renderering of mapcanvas is still active

i am working with qgis c++ api 2.8.2 and qt4.8.5 i want to disable the rendering during zoom in or zoom out fonction in order to have a fast zoom i try to use : MyMapCanvas->stopRendering(); ...
1
vote
1answer
22 views

problem with my zoomIn or ZoomOu

i am using qgis 2.8.2 and qt4.8.5 i have a problem when i call zoomIn or ZoomOut, the raster on canvas is reduce or zoomed but : - the raster size change - it disaprar - it appear again but 3 to 5 ...
0
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0answers
17 views

OGRGeometry::exportToWkb return buffer empty

I would like to export OGR Geometry in WKB format. I used the function OGRGeometry::exportToWkb from OGR. The problem is that the buffer returned by the function is empty and OGRERR_NONE is always ...
1
vote
1answer
67 views

DLL that uses QGIS

I want to create DLL which opens a dialog do some processing with QGIS and returns some data. I have searched many places but have not found the help I needed. I just want to read shapefiles and then ...
1
vote
1answer
12 views

problem with qgsmaptoolpan

i am using the c++ api qgis 2.8.2 i have a strange problem when i want to use the pantool for my canvas i used this code : mpPanTool = new QgsMapToolPan((QgsMapCanvas*)mpMapCanvas); ...
0
votes
1answer
77 views

How to increase performance for nearest neighbour query using a multipoint? (Boost Geometry)

The following function gets the nearest point in an rtree to a multipoint geometry. I'd like the performance of the function to be better. Is there any way to make it faster? TimingLink* ...
0
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0answers
96 views

GDAL in C++: Resize Image (gdal_warp?)

I would like to resize a geotiff using GDAL in C++. Searching online, I bumped into another question here that explains it is possible through gdal_warp and gdal_translate via terminal. But there ...
3
votes
1answer
79 views

Extracting values from raster under line using GDAL?

How can I find the cells which lie on a straight line between two points? I.e. how can I find the indices of the cells (in grey) which are intersected by the line defined by the two points (in blue): ...
3
votes
1answer
55 views

ArcGis 10.2 returning an enum status of EsriLicenseNotLicensed

I have an old VS project that was using ArcGis for a map control. I now have 10.2 on my machine. code that I used previously to find & initialize the license no longer works. I know the enums ...
0
votes
1answer
59 views

GDAL in C++: Wrong Raster Values After Cropping geoTiff Dataset

I'm trying to transfer a subset (box (0,0)-(300,300)) of a panchromatic geotiff to a new file. Although the georeference and the set are transferring correctly, the raster values seem off. Loading ...
0
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1answer
50 views

how do i create OGRSpatialReference from raster file's georeference C++

I want to create .shp file using ogr with georeference based on my raster file, so i create an ogr layer using CreateLayer( "point_out", NULL, wkbPoint, NULL ); i want to set the OGRSpatialReference ...
1
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2answers
37 views

Building error on enum of the QgsMapToolIentfy Class

I am working on a project in c++/QT4.8.5 based on the api c++ 2.8.2 of QGis It is a stand alone application I had to get information of a layer by clicking on it in the canvas So I decide to use the ...
1
vote
1answer
56 views

How to select a feature with the mouse click programmaticaly

I am working in c++/QT 4.8.5 and the api c++ qgis 2.8.2 In my application i had top select layer with the mouse click button to get attribute value and show them in a popup windows I see in the api ...
2
votes
1answer
50 views

Read SRTM HDG elevation files with C++ / Strange negative numbers (not Null)

I'm trying to write a little C++/OpenGL utility with which I could manage SRTM HDG files. For now, I'm just trying to read the files correctly. So I downloaded a sample tile from the main server, ...
0
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0answers
31 views

2 Lat/Long Segments Defined By 4 Lat/Long Points - Calculate If They Intersect & How Far Along Segment They Do

I have 2 lat/long segments defined by lat and long end points. For example, I have Segment X (defined by A.lat, A.long and B.lat, B.long where A and B are end points) and similarly Segment Y (defined ...
0
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0answers
33 views

how to add vectorlayer in a mapcanvas with a raster

I am working in c++/qt4.8.5 with qgis api 2.8.2 For my application I had to load a raster in a mapcanvas, then with different action I had to add pint , line or polygon Is there a simply way to do ...
1
vote
1answer
54 views

How to re-render only a single layer on a mapcanvas?

In my application I have a mapcanvas that contains several layers. some of layers need to be updated or rendered again because data has been changed ( like the geometry or some attributes ) Is there ...
1
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1answer
66 views

Problem creating polygon in a layer

I am working in c++ qt4.8.5 and api qgis 2.8.2 c++. In my application I had to put polygon to define attractive zone. I found a great post in stackexchange (86812). I have based my on this post and on ...
1
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1answer
43 views

How to create a specific svg file with data from a feature

I am working in c++/ QT4.8.5, with qgis api c++ 2.8.2 I have to display a dynamic icon for a feature. some of the data change periodically and in order to display the change i need a svg that can get ...
1
vote
2answers
81 views

is it possible programmatically to rotate a svg of the feature without rotate all feature

I am working on a project that need to move and update the shape of the feature of the layer. I am working in c++/ QT4.8.5 and qgis api c++ 2.8.2. In my Layer I have a lot of features, each feature ...
1
vote
1answer
95 views

C++ code and ArcGIS Button

I have some code in c++ that used gdal and process raster and create an output raster. I want to create a button in ArcGIS Desktop (using ArcObjects SDK 10.2 c#) and pass the raster layer to my c++ ...
1
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1answer
85 views

Is it possible to change the geometry without startEditing the layer

I am working in c++/QT 4.5 with the QGis 2.8.2 API. I had to change the geometry of features in a layer each second. Each second new data comes from the Ethernet connection, the application gets the ...
1
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1answer
43 views

How to change programmatically the value of attribute in one of several feature in a vectorLayer

I have a vectorlayer that contains a lot of feature, I know that each feature has an unique Id Each of them has some propertie like coordinateX, coordinateY, color, name With a QTimer, each 2 sec I ...
1
vote
1answer
17 views

Building error on changegeometryvalues

I am working with c++/QT and c++api gqis 2.8.2 I want to change the geometry of a feature, I have this code : QgsVectorLayer * lLayer = mMapLayer.value(TRACKS); QgsVectorDataProvider * ...
1
vote
2answers
59 views

how to rotate a symbol

I am working in c++/python/QT 4.5 with the api qgis 2.8.2 My application receive data from a communication port that indicate the change of position of an object diplayed on the map and represented ...
1
vote
0answers
15 views

How to change the value tof the use tag in a svg file

I am working in C++/QT4.5 with the qgis c++ api 2.8.2 I have a svg file that contains different form tag by Id When i want the first form i place the id name in the use xlink:href="#formname" .... ...
4
votes
2answers
83 views

IRasterLayer background transparency in C++ with ArcObjects 10.x .NET

I have a georeferenced IRasterLayer which is displaying data from a PPM file with no alpha channel. I am trying to specify a color which should be treated as transparent. In ArcMap it is possible to ...
1
vote
1answer
29 views

How to add a point in a empty vetorLayer creadted in memory

I am working in c++/qt 4.5 and qgis api c++ 2.8.2 I had to create and empty vectorLayer and add Point I saw in the qgis cookbook that it is possible to create a vector layer in memory ,I did that, and ...
0
votes
1answer
33 views

How can i catch clicked signal on a qgsmapcanvas

I am working under c++ with the qgis API 2.8 In order to make different operation on a canvas like personnalized rotation or selecting a region for zooming, I had to catch different signal like ...
0
votes
0answers
64 views

Showing an Overview map with the ArcGIS C++ QT Runtime

I am using the Esri ArcGIS QT API for C++ and trying to create an overview map for my application as found here: Multiple maps - https://developers.arcgis.com/qt/cpp/guide/multiple-maps.htm I am ...
1
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0answers
25 views

How to SetVisible a layer without redraw all the mapcanvas

I am working with QGis 2.8.2 API c++/ QT 4.5 I am displaying a lot of layer in a mapcanvas, I am looking for a method like setVisible(boolean ) in order to setvisible or not a specify layer ...
1
vote
1answer
59 views

Convert Shapefiles into Raster — C++

I'm coding an algorithm which uses as an input a map from QGIS. The software has been implemented in C++ and my idea is to convert, automatically, a shapefile into a raster one. Is there any function ...
1
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0answers
32 views

VectoreLayer Still Empty even if attribute has been set with value

I am working with the qgis api c++ 2.8.2, my application is written in QT 4.5.3 / C++ I had to create a vectorlayer in memory with attributes and features and export it to a shp file to import it in ...
1
vote
2answers
41 views

Building error with QgsVectorFileWriter

I am working with qgis api c++ 2.8.2, in c++/QT 4.5 I try to save my List of QgsField but I have the error message : no matching for call to 'QgsVectorFileWriter' I took the sample from here : ...
0
votes
0answers
21 views

Problem with VectorLayer created in memory

I am working in c++/QT whithnthe qgis API c++ I had to build a personnalized vectorlayout called "TRACKS" , so i write a function that create in memory the vectorlayer like this : QgsVectorLayer ...
0
votes
0answers
14 views

List of default attribute of a feature?

I am working with c++/!qt with the c++ api qgis 2.8.2 for a stand alone project application I had to change and add attribute for feature Does anyone know where i can find the default attribute of a ...
0
votes
0answers
32 views

Need help on how to move a symbol over a map

I'm working in c++/qt and the c++ api qgis 2.8.2 In my application i load a map with a s57 file, this part works perfectly, now i need to make some plot representing different object like boat, plane, ...
0
votes
0answers
7 views

SegFault on create an EmptyDataSource From a typedef

I had to create a specific type of point, in order to do that I create a function that create a layer from shp file and data extract of the Code : typedef bool ( *createEmptyDataSourceProc ) ...