A mosaic map is a map made up of different images which are displayed depending on availability and zoom level.
The mosaic map can have one or more overlapping layers, so, if you zoom in or zoom out, one or another layer will be shown. For example, if you zoom out, low quality layers will be displayed. On the other hand, if you zoom in, it will show more detailed layers (depending on availability).
Less detailed layers are called 'overviews'. Each overview layer is a single *.RTMAP file that covers the entire area of a country. It won’t be stored at RTMAP folder.
The most detailed layer is made up of 'tiles' (square sections which form the mosaic). As overview layers, tile files also have *.RTMAP extensions, but tiles are stored at RTMAP folder. Thus, the content of the RTMAP folder will be the most detailed layer.
When the user is zooming into the most detailed layer, the software will automatically look for an available tile at RTMAP folder ( [COUNTRY]+_RTMAP ). If that one exists, it will be shown. If not, overview layer will be displayed.
You can download more map tiles and save them at RTMAP folder in order to have a larger maximum detailed layer. To open a mosaic map, you must first select the Topo.imp file ( [COUNTRY]+ Topo.imp ) which will automatically search for the best available picture for every single moment. In conclusion, the mosaic map has these parts:
- IMP file (for example: Spain_Topo.imp): Controls when each layer is being shown. If you want to open the map, you must select it..
- 'Overview' layers (for example: Spain_Topo_layer_200k.rtmap or scan1000_4.rtmap): Each layer is a single file for the entire country (see links at the bottom).
- Layer of tiles (*.RTMAP files inside SPAIN_RTMAP folder)
These elements must be stored within maps folder (structure has to be the same).