Knowledge Base

KB10652 - Set a transparency level for individual shapes.

This is possible, but not very efficient. You must override OnPaintShape event and then: procedure TForm1.doPaintShape( const _sender : TObject ; const _shape : TGIS_Shape ) ; var hndl : Integer ; begin hndl := GIS.LockTransparent( 50 ) ; _shape.Draw ; GIS,UnlockTransparent( hndl ) ; end ;

Modified: September 10, 2015

KB10648 - DK support for proprietary data formats.

The DK API can be used to read/write various formats not supported directly in the DK: All shapes in a layer can be traversed using FindFirst()..FindNext() Any vertices from a shape can be accessed using GetPoint() A new shape can be added to a layer and then new vertices added to the shape using AddShape(0), AddPoint() The TatukGIS DK provides a unified API to GIS objects based on: Layers Each layer contains a Shape Each shape can be point, line, or polygonal Upon reading any vector data ...

Modified: September 10, 2015

KB10646 - Labels and charts in image exported with DK ExportToImage are different size than viewed ...

The last parameter of the ExportToImage function specifies the DPI setting (dots per square inch). The default DPI value in the DK is 300, but the computer screen may have a different DPI. To export image to appear the same as on the computer monitor, set the DPI parameter accordingly.

Modified: September 10, 2015

KB10642 - Generate cendroid points layer from a polygon layer.

The TatukGIS Editor's topology builder functionality can generate a new vector points layer from a polygon layer with each point reflecting the centroid position of the matching polygon. Each point shape will have the same attribute values as the matching polygon. With the polygon layer open and highlighted as the selected layer, select the Tools/Topology/Topology menu to open the Topology builder and corrector combo box . Then select Polygonal as the Topology type and select the Centroid ...

Modified: September 10, 2015

KB10641 - Query for intersection between two streets on a vector street map layer.

It is possible to query for two streets to easily see the place where the two selected streets intersect. (The only way to actually query for an intersection itself would be if there were a map layer containing point objects representing the locations of the street intersections.) The correct SQL Builder query string to use is: (name = 'xxx') or (name = 'yyy') You must use "or". "And" will not work because it is impossible to have two names for a single vector shape, i.e., street line.

Modified: September 10, 2015

KB10640 - Clustering and load balancing techniques with DK.ASPNET web GIS application.

The implementation of load balancing and/or clustering to run a DK.ASPNET developed web GIS solution on multiple servers is just matter of using the built-in clustering/load balancing options in the Windows operating system. There will is no requirement to modify or reconfigure your web application for this.

Modified: September 10, 2015

KB10634 - DK method to create a bitmap.

Just use the DK function PrintToBmp.

Modified: September 10, 2015

KB10630 - Perform a spatial selection using a shape from another layer.

There are two ways to use a line or polygon to spatially query on a vector layer. Manually draw the selection line or polygon using the Select feature supported both the TatukGIS Editor and the free GIS Viewer. Use the geometry of a line or polygon shape from a different layer to perform the spatial selection by copying the shape geometry to the Editor clipboard and then using the content of the clipboard layer to perform the selection. The spatial selection functionality in the Editor is advanc ...

Modified: September 10, 2015

KB10629 - Source of sample GML data to test with TatukGIS products.

Sample GML data can be obtained from the web site of the Ordnance Survey organization in the United Kingdom. http://www.ordnancesurvey.co.uk/

Modified: September 10, 2015

KB10628 - Editor/Viewer toolbar icons provided with DK.

All TatukGIS toolbar icons are provided with the DK retail versions.

Modified: September 10, 2015

KB10626 - Add or retreive custom information to a *.ttkgp project file.

Simply use: Layer.ConfigFile.WriteString( 'MyCustomProperty', 'some_value'); To add a whole new section to the project file, use: GIS.ProjectFile.Section := 'MyPrivateSection' ; GIS.ProjectFile.WriteString( 'MyCustomProperty', 'some_value');

Modified: September 10, 2015

KB10623 - Linear referencing functionality for data storage.

Linear referencing (sometimes referred to as dynamic segmentation) involves storage of geographic data (such as a pipe or road segment) to a relative position along a linear feature (such as a pipeline in a utility network or a road in a road network model) without explicit use of x,y coordinates. Each segment can have unique attribute information. For linear referencing with the DK, refer to the DK functions: TGIS_ShapeArc.GetPointOnLine TGIS_ShapeArc.GetSegment

Modified: September 10, 2015

KB10621 - LZW compressed TIFF image renders slower after conversion from color to gray scale.

Probably the color TIFF LZW (compressed) image is compressed in strips, with each strip of separate compression containing a few lines. Probably the software you used to convert the color TIFF to the grayscale TIFF LZW compressed the entire image together, resulting in a single strip containing the whole image. In such case, the TatukGIS software must decompress whole image to display any portion of the image. Try recreating the TIFF LZW grayscale image using different settings, or perform the convers ...

Modified: September 10, 2015

KB10617 - Access and display ECW data from a ECWP server.

Regarding DK products, access the file as usual. So use GIS.Open or just provide the path to the constructed TGIS_LayerECW object. Regarding the Editor or free Viewer products, create a TTKP file using a text editor and enter: [TatukGIS Layer1] Path=ecwp://server_name/file_name.ecw

Modified: September 10, 2015

KB10611 - Scaling problem using Params.Area.Symbol to fill polygon area with a bitmap symbol.

The problem is caused by the scaling of the symbol, which can result in horizontal or vertical gaps between the symbols. The solution to guarantee a smooth fill is use instead Params.Area.Bitmap. Alternatively, try to set Params.Area.Symbol.Size to the pixel size that is adequate for the image (maximum value for Width & Height).

Modified: September 10, 2015

KB10608 - Support for the Egenhofer operator.

The DK supports the DE-9IM model (developed by Clementini and Felice), who dimensionally extended the 9 Intersection Model developed by Egenhofer and Herring.

Modified: September 10, 2015

KB10607 - Icons (an ICO file) used for map symbols display with wrong placement.

Icons do not support scaling. Assign a fixed size such as 32px (-32) or some other value depending on the size of icon file used (16, 32, 64, etc.).

Modified: September 10, 2015

KB10602 - Hide display of some shape attributes on TGIS_ControlAttributes.

This is achieved by marking field.Hidden = True or field.ReadOnly = True. You can access an individual field using the Layer.Fields property or using layer.FindField( name ) function. Then select Hidden for a selected field(s).

Modified: September 10, 2015

KB10600 - Limit records displayed from joined database.

This can be accomplished just by narrowing the scope. For example, to limit display of records to only those associated with New Zealand, use something like: Layer.Scope = "location LIKE 'new zea%'"

Modified: September 10, 2015

KB10579 - Provide user defined passwords for SQL layers.

Embed tokens into the connection strings. For example, if in the connection string you have: ADO=Provider=Microsoft.Jet.OLEDB.4.0;Data Source=test.mdb;user=<#user#>;pwd=<#password#> OnPassword event will be called twice upon the first connection to a database asking to resolve the strings: user & password.

Modified: September 10, 2015

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