Loading GIS shapefile in Processing

Hello friendly people,

I would like to ask you about the optimal process of loading, drawing and using data of complex vector data (points, lines or polygons) such as GIS shapefiles. I have searched a lot and this is what I’ve found:

  1. Use the MapThing library as suggested here MapThing = a collection of classes for reading and displaying Shape files (a.k.a. ESRI shapefiles), CSV, and GPX data in a map-based sketch.
    Unfortunately MapThing seems to not read Shapefiles properly, even with the correct coordinate system.

  2. Convert the shapefile to GeoJSON and use the Unfolding Maps library and its GeoJSONReader class as explained here. Then the draw() function can show the vectors.

  3. Convert the shapefile to GeoJSON or CSV (table including coordinates), and use the native functions of Processing to extract data from it. This method is used in several tutorials across the web, but I could not find anything about how to draw polygons…

All those possibilities are getting me confused so if you had any clear and efficient (model shall be as light as possible) methodology and examples, I would be happy to learn from you. I put the emphasis on the fact that I want to (1) load, (2) draw and (3) use data included in GIS shapefiles. For example, showing polygons of buildings in a city with an attribute of number of storeys.

Thank you for your help,

Best regards,

Antoine Saurat