Program of forming a map in a raster kind for WEB-applications
The program is intended for creating a set of raster maps by the chosen scale range of a vector map.
The purpose to form a set of rasters is a acceleration of displaying maps in the WEB-applications containing a plenty of objects (more than 10000).
Input data are:
- map in format MAP or SIT,
- user maps in SIT format.
Output data are:
- raster maps in RSW format,
- file of the project in MPT format.
Selection of scale range for the formation of a set of raster maps is made of the overall scale of the series. The total scales range contains the following scales:
1 : 40 000 000, 1 : 20 000 000, 1 : 10 000 000,
1 : 5 000 000, 1 : 2 500 000, 1 : 1 000 000,
1 : 500 000, 1 : 200 000, 1 : 100 000,
1 : 50 000, 1 : 25 000, 1 : 10 000,
1 : 5 000, 1 : 2 000, 1 : 1 000,
1 : 500, 1 : 200, 1 : 100,
1 : 50, 1 : 25, 1 : 10,
1 : 5, 1 : 2, 1 : 1
By base scale of the main map the average scale of the scales list of rasters is set. Others are selected from the total scale range (from an average 50-fold increase or decrease the denominator of medium-sized).
The input maps and constructed rasters are collected into the project file (MPT). In this project file as the lower limit of visibility of the input maps the scale 1:1 is set. The upper limit of visibility of input maps corresponds to the lower limit of visibility of the raster of the largest scale from the scales list of rasters selected for the construction.
Borders of rasters visibility are placed into a file of the project and correspond to ranges between neighboring scales of overall scale range. The upper boundary of the raster of the smallest scale is set equal to the maximum (1: 2,000,000,000).
The maximal size of formed rasters is equal 4 gigabytes. For each scale it is formed one or several rasters.
Process of formation of raster maps of great volume (more than 10 gigabyte) can take a lot of time (one hour or more). Therefore during an execution the calculation of execution time is made. The timing of implementation is made after recording the first 500 megabytes of raster data (from 4 to 10 minutes from the beginning of the process) and confirmed before the end of the process. The difference between the actual execution time and the initial estimated time of typically less than 20 percent.
For opening the main map (the file with extension MAP or SIT) is necessary to choose in the menu of the application main form the item File - Open map. Opening of a map is carried out with a delay (from 1 till 5 seconds). During this moment the calculation of the sizes of raster maps (in mbytes) and request for the free space on a disk in the catalogue of a map (for placement of raster maps) is carried out.
If necessary to the main map the additional user maps (files with expansion SIT) can be added. Addition of additional user maps is carried out at a choice of the menu File - Add user map.
If necessary to switch off some layers or types of objects the setting of map contents (the main and additional) can be done. Setting up of map contents is carried out at a choice of the menu File - View - Map contents.
Language of the interface (Russian, English) can be changed in the menu File - View. The chosen language of the interface is kept in a file RswMaker.INI. At restart of the program the language of the interface is restored.
Choice of the menu Help - Information opens the form Information containing the description of work of the application.
Start of process of the rasters forming is carried out by the Execute button. By pressing the Cancel button (during an execution) the stop of process is carried out. During an execution the number of processed scales can be changed.
Upon termination of process in the catalogue of a map the file of the project is contained («Name of the project.MPT»), in the enclosed catalogue («Name of the project_MPT »), regarding the placement of the project file, the constructed rasters are contained. The file of the project contains names of files of input maps and constructed rasters. This file (MPT) is intended to open vector and raster maps by packet mode.