I am working on a MapInfo plugin to convert MapInfo files to GeoJSON files.
I am having trouble matching up the object types of the two formats. Each GeoJSON object type is described in the documentation. The MapInfo object types are a bit more ambiguous. The best I can find is in the MapBasic reference file which says, for example:
- OBJ_INFO_TYPE value: OBJ_TYPE_REGION
- ID: 7
- Object type: Region Object
This is obvious enough but what exactly is a region? Is it analogous to a Polygon? Or is it any closed object?
Can anyone point me towards a decent definition of each object type?
I sent a message to the MapInfo support people who pointed me towards a section in the MapInfo User Guide headed "Map Objects as Part of Layers" which spells things out perfectly. I still can't find this page in the guide that I have (version 10.5) so I'll paste the relevant section below for anyone else in my position.
Quote starts here:
MapInfo Professional are made up of layers of map objects. There are five basic types of objects:
- Regions: closed objects that cover a given area. These include polygons, ellipses, and rectangles. For example, country boundaries, postal code boundaries, sales territories.
- Point objects: represent single locations of data. For example, customer locations, restaurants, parking meters. Points can also be combined into multipoint objects.
- Line objects: open objects that cover a given distance. These include lines, polylines, and arcs. Examples are streets, rivers, power lines.
- Text objects: text that describes a map or another object, such as labels and titles.
- Collection objects: combination of region, line, and multipoint objects.
You can have each type of object in a separate layer (most common), or you can combine objects in the same layer.