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Testing the topo-tuscany.sqlite sample database
This quick tutorial explains by, practical step by step examples ,how to use the Map Panel tool.The goal is to familiarize yourself with the new Map Panel feature, by repeating each single step shown.
- You need to download the topo-tuscany.sqlite sample database.
- Then you must start spatialite_gui 2.1.0, connecting to this database.
Step #1: displaying a Vector Coverage containing a full TopoGeo
| The topo-tuscany.sqlite sample contains the topogeo Vector Coverage that represent a complete Topology (ISO TopoGeo). Such a Vector Coverage has nothing exceptional in SpatiaLite, and simply requires applying a rather complex Style. The whole Topology is considered as a single Coverage of the mixed Geometries type, and all topology primitives are internally arranged into the following classes:
You can read a comprehensive definition of Nodes, Edges and Faces from here The intended role of EdgeSeeds and FaceSeeds is explained here |
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| The figure on the side is an example of a Topology rendered on the Map Panel. As you can easily notice the Faces (POLYGONs) are not displayed. This always is the default setting applied by SpatiaLite; materializing the Faces (which are created from the Edges) could easily cause a slow rendering process, most notably when a huge number of Faces have to be displayed on the Map. |
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| The Configure dialog supporting Topology-based Vector Coverages allows to selectively enable/disable the individual Primitive classes. |  |
| The figure on the side exemplifies how the same Topology, seen in the previous step, will be rendered on the Map after enabling the Faces and disabling both Edges and EdgeSeeds |  |
Step #2: displaying a Vector Coverage containing a full Spatial TopoNet
| The topo-tuscany.sqlite sample contains the toponet Vector Coverage that represent a complete Network (ISO Spatial TopoNet). As you have already seen with the Topologies Coverage, such a Vector Coverage simply requires applying a particularly complex Style. The whole Network is considered as a single Coverage of the mixed Geometries type, and all topology primitives are internally arranged into the following classes:
You can read a comprehensive definition of Nodes and Links from here The intended role of LinkSeeds is explained here (LinkSeeds are the equivalent of what EdgeLinks are in a Topology). |
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| The figure on the side exemplifies how the same Network, seen in the previous step, will be rendered on the Map. |  |
| The Configure dialog supporting Network-based Vector Coverages allows to selectively enable/disable the individual Primitive classes. |  |
| The figure on the side exemplifies how the same Network, seen in the previous step, will be rendered on the Map after disabling the LinkSeeds. |  |
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