Documentation contents: INTRODUCTION Background (MS-DOS) Micro WDB II File Composition Disclaimer WORLD DATA BANK II (Amiga) Display Routine, Version 2.2 Overview Instructions For WDB Running WDB Forcing Use of a Single Data File Adjusting Aspect Ratio Navigating The Display Choosing A New Vantage Point Known Bugs Instructions For SAT Instructions For SELECT Credits _____________________________________________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~ INTRODUCTION ============ ~~~~~~~~~~~~~~~~~~~~~~~~~~ The following information is from the original MS-DOS version of the WDB-II program, written by Fred Pospeschil. It explains the background of the CIA derived map data for those who are interested (or might have the resources to replace the data with something more current). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The full WDB-II is a digitial map data base produced by the Central Intelligence Agency (CIA) and distributed by the National Technical Information Service (NTIS), U.S. Department of Commerce, 5285 Port Royal Road, Springfield, VA, 22161. Micro WDB-II is a highly compressed version which is suitable for use on micro computers and was put in this configuration by Micro Doc. Before describing Micro WDB-II a few words should be said about the source file - WDB-II. The following paragraphs are paraphrased from the NTIS overview of WDB-II. WDB-II is a digitial representation of the world coastlines and boundries suitable for use in automated mapping systems. It contains approximately six million discrete geographic points and was digitized using all available sources of information. Map scales used range from 1:750,000 to 1:4,000,000 with a nominal scale of 1:3,000,000. These points are grouped by and identified as describing (1) coast lines, (2) country boundries, (3) state boundries (USA only), (4) islands, (5) lakes, and (6) rivers. Each of these groupings is further broken down into features and subordinate classifications/ranks. These ranks are hierarchically structured, and are also used for plotting symbol definition. WDB-II, as provided by NTIS, is in a 20 character format on five 9 track EBCDIC one-half inch magnetic tapes. This data base consists of two types of records, one for the line segment identifier data, and the other for the latitude and longitude values of each discrete point making up the line segment. In this format latitude and longitude values are recorded only as integers in degrees, minutes, and seconds. WDB-II is available for $660.00 (Order Number PB-271 874 SET/HBG). Clearly, WDB-II is an excellent data source when making large (4 x 6 foot) plots on a mainframe or minicomputer. It is, however, somewhat large (150 - 200 megabytes) for use on microcomputers. Even on the larger commercial online graphics systems, many points have to be filtered out before generating displays. For this reason many people have spent considerable time over the past to filter and compress this data into a form which could be used in desktop computers. To these people we wish to express our appreciation - particularly Antonio Riveria who provided us with a copy of the latest download of the file. Background ========== The present version began as a three megabyte ASCII text file which contained some 179,000 points selected from all six of the line types described above. This file was then converted into a sixteen bit integer format which reduced the size to just over one megabyte. Since this was still a little large for most five inch disk formats the file was divided into six files - one for each of the six line types. The coast line file was further divided into two files as it was over 400 KB. With this processing completed the file was configured such that it could be readily moved to most desk top microcomputers using the MSDOS disk format. The following table provides a brief statistical overview of the six line types which are contained in the data base. Micro WDB-II File Composition ============================= Detail COAST COUNTRY STATE ISLAND LAKE RIVER Total Level .PNT .PNT .PNT .PNT .PNT .PNT 1 29150 8573 798 13781 5886 11146 69339 2 35077 10172 959 16077 7080 13217 82599 3 5470 1496 153 2524 1023 1817 12526 4 4000 1249 101 1945 820 1254 9502 5 1478 869 248 844 309 760 5365 Total 75175 22359 2259 35171 15118 28194 179331 Lines 208 301 111 344 103 196 1263 Size (KB) 449 134 14 211 90 169 1067 The above table shows the number of points which are in each file and for each level of detail. It also shows the number of line segments in each file and the file sizes in kilobytes. Detail level 5 contains the fewest points and produces the least detailed graphics image. The points at each level of detail are additive to the points at all lower levels. For example, when using detail level 4 the points from both levels 4 and 5 must be used / retrieved. Therefore, if one were drawing coast lines at detail level 4, a total of 5478 (4000 + 1478) points would be processed. These 5487 points will describe 208 line segments of various lengths. [NOTE: For the Amiga version, the structure of the data as described above has been altered. Detail level 1 now incorporates all data from the lower levels. It also combines data from each of the six groups into a single file. Lower detail level files are subsets of the detail level 1 file, and similarly incorporate all data from levels below them. The statistical distribution of the data points otherwise remains as described.] Note that the same number of line segments exist at all levels of detail. For example, regardless of which level of detail is selected, there will always be 208 line segments described by the coast line data file. In some cases, mostly in the islands file, line segments degenerate to single points at the lower levels of detail. Therefore, programs which process this data must check to see whether each line segment header record is followed by a point record or another line segment record. More will be said about this later. Actual use of the data in these files has shown that most displays which cover a reasonably large area do not need all of the detail provided at level 1. A large area would be a major portion of the U.S. For large area plots level 3 or 4 is normally sufficient and greatly reduces the number of points which must be processed. Disclaimer ========== This product contains/uses data and/or code placed in the public domain by Fred Pospeschil and Antonio Riveria. Original coordinate data was created by the Central Intelligence Agency. ALL USERS OF THESE MATERIALS ARE TOTALLY RESPONSIBLE FOR THEIR USE AS THESE MATERIALS ARE PROVIDED WITHOUT EITHER EXPRESS OR IMPLIED WARRANTIES OF ANY KIND. For information related to the original MS-DOS version only: Fred Pospeschil 3108 Jackson St. Bellevue, NE 68005 402-291-0795 (6-9 PM Central) _____________________________________________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ WORLD DATA BANK (Amiga) Display Routine, Version 2.2 ~~~~~~~~~~~~~~~~~~~~~~~~~~ OVERVIEW ======== ~~~~~~~~~~~~~~~~~~~~~~~~~~ This program displays the CIA database of the geography of the world. The executable file is under 11K, and its takes about 137K to execute, including hi-res interlace screen and intuition interface. Features: · Slider gadgets for adjusting latitude, longitude and magnification factors · Integer arithmetic for scaling, hence faster calcs · Area clipping to avoid spending time plotting off-map points · Compensation for monitor "stretch" (aspect ratio distortion) · Automatic centering of next display from any point in current display · Choice of cylindrical or spherical projection The files in this set are described as follows: LEVIATHAN.LHA -- This enormous archive conatins the master 1.1 Meg data file for use with both the WDB and SAT display programs. The Big File, WDB.1.ALL, contains the data points in all six groups described above. It can be broken down by the SELECT program into four smaller subsets named WDB.2 through 5.ALL. (WDB.5.ALL has also been provided separately to allow you to run the program without extracting this archive). These smaller data files also will contain data from all six groups, but provide correspondingly faster drawing and less detail. The WDB.5.ALL subset furnished is the smallest, fastest, and least detailed. SAT -- This executable program draws a spherical view of the Earth from a fixed altitude approximating 30,000 miles. It uses the WDB.5.ALL data file (the smallest, with least detail). The latitude and longitude of your vantage point are adjustable. SAT8 -- This is a special version of the SAT program above for use ONLY ON MACHINES EQUIPPED WITH A MATH CO-PROCESSOR. *WARNING!* This program *WILL CRASH* if run on a machine not so equipped. SELECT -- This program may be used to create one or more of the four data files which are subsets of The Big File. WDB -- The World Data Bank executable program draws a cylindrical projection of the Earth. Your vantage point is adjustable in latitude, longitude, and "altitude" (magnification factor). WDB automatically chooses one of the five data files to use based upon the magnification factor selected. Other files -- Also included are icons for Workbench executable programs (WDB.info, SAT.info), along with smaller alternate icons for each (WDB.alt.inf, SAT.alt.inf). To use the alter- nate set of icons, simply delete WDB.info and SAT.info from a CLI, then rename WDB.alt.inf as WDB.info and SAT.alt.inf as SAT.info. ~~~~~~~~~~~~~~~~~~~~~~~~~~ INSTRUCTIONS FOR WDB ==================== ~~~~~~~~~~~~~~~~~~~~~~~~~~ You may run WDB or SAT using the smallest (least detailed) data file right now simply by clicking on either icon. If you wish to see greater detail you'll need to dissolve the LEVIATHAN.LHA archive, placing the resulting WDB.1.ALL file in the same directory as the WDB and SAT programs. As explained below, you will probably want to use the SELECT program to create the intermediate data files between The Big File and WDB.5.ALL, but it's not necessary, especially if disk space is too tight to waste on redundant data. Running WDB =========== To call it from CLI, type: WDB To call it from Workbench: double click on the WDB icon WDB Automatically selects the input file based on the magnification factor chosen according to the following scale: mag 0.85 - 2.00 --> wdb.5.all ( 25,890 bytes) mag 2.00 - 6.00 --> wdb.4.all ( 82,080 bytes) mag 6.00 - 12.00 --> wdb.3.all ( 156,960 bytes) mag 12.00 - 36.00 --> wdb.2.all ( 652,428 bytes) mag 36.00 - 125.00 --> wdb.1.all (1,068,408 bytes) The name of the file being shown appears in the lower right of the Control Window. If the automatically selected file is not available in the current directory, the next most accurate file (lower numbered file) available is used. Note that the size of the file and the detail available for display increases for *lower numbered* files. Using various files allows for displays of greater magnification to maintain better detail without the time penalty of passing through the largest file for displays which require lesser detail. Perhaps someone will have some better ideas for correlating the magnification scale to the different data files. Speak up! Forcing Use of a Single Data File ================================= From CLI, specifying a datafile on the command line will cause WDB to supress automatic file selection, instead using only the file specified. For example, "WDB WDB.3.ALL" will display only points from the file WDB.3.ALL. Adjusting Aspect Ratio ====================== There is a Distortion Comp(ensation) factor control designed to compensate for monitor "stretch" that will be different for different monitors. The program defaults to a value of 1.2, figured at the equator, which seems to work best with the 1080 monitor. It may require some experimentation to find a setting that produces acceptable results with other monitors. Try looking at the shape of Africa on a good globe and adjust the value in the Distortion Comp text gadget until the shape of Africa on screen approximates that of the globe. Navigating The Display ====================== Using one of the available data files, WDB draws a cylindrical projection of the world's coastlines, political boundaries (including states in the U.S.), islands, rivers, and lakes. The default vantage point is at the junction of the equator and the Greenwich meridian. A default magnification factor of 1.0 provides a projection of the entire globe. On screen is a control panel offering an intuitive set of controls. They include both text gadgets and sliders for selection of the longitude and latitude in degrees and minutes, and the "altitude" (magnification factor) of your vantage point over the earth. You may adjust the sliders to an approximate value, or enter a precise value in the text gadgets from the keyboard. Menu items allow you to hide/show the menu bar and remove/restore the control panel for screen captures. The PLOT button draws a screen according to the control panel settings; the QUIT button quits the program. A drag bar on the control panel allows it to be moved to a different location on screen. Maps are drawn with colors which indicate the class of data points to which they belong. Continental coastlines are dark green, islands are bright green, rivers and lakes are dark and light blue, respecively, major political boundaries are red and minor ones (states) are yellow. At greater magnifications, and especially with the more detailed data files, the program may at times appear to halt momentarily. This is normal, as the program clips data which falls out of bounds of the window displayed on screen. When drawing is concluded the control window will reappear. If you end up with a completely black screen when the control panel reappears, you've chanced upon a section of the globe which is entirely devoid of features, such as an ocean. To regain your bearings, reduce the magnification factor and replot. Choosing A New Vantage Point ============================ If you haven't a clue to the latitude and longitude of a location you'd like to examine, WDB has a feature which allows you to select a point on the current display with a click of the Left Mouse Button. This will set both the longitude and latitude to that point, which becomes the vantage point for the next display. To avoid having a desired vantage point end up off the screen, you should make the selection of your target vantage point before experimenting with greater magnification factors. [See "Known Bugs"] Known Bugs ========== I've noticed that when the magnification factor is low (around 1.0 - 3.0), the mouse pointer location does not convert very accurately into longitude and latitude. I'm not sure why. Perhaps rounding. (??) The WDB program uses integer arithmetic (i.e., fixed-point math) to gain speed. This introduces rounding. ~~~~~~~~~~~~~~~~~~~~~~~~~~ INSTRUCTIONS FOR SAT ==================== ~~~~~~~~~~~~~~~~~~~~~~~~~~ This program displays a single data file as a two-dimensional projection of a sphere. Unlike WDB, SAT's "altitude" is fixed at around 30,000 miles. Therefore SAT does not use multiple data files. In this version the program expects to read the smallest, fastest, and least detailed data file (WDB.5.ALL) since not much detail is visible at this altitude. Slider gadgets allow you to change the coordinates of the nearest visual point of the sphere (your vantage point). The vertical slider adjusts latitude; the horizontal one is for longitude. You may also choose to enter a specific number (in degrees) directly via the text gadgets. In this version, SAT does not allow the selection of latitude and longitude coordinates from the mouse pointer. There are two versions of this program: SAT - the regular version SAT8 - a special version for those with M68881 math co-processors. NOTE: DO NOT ATTEMPT TO RUN SAT8 IF YOUR SYSTEM IS NOT EQUIPPED WITH A 68881 MATH CO-PROCESSOR OR A CRASH WILL OCCUR. Both programs use the same data files as WDB, although in the current version, both look for a file called "WDB.5.ALL". If you prefer to view more detail (and can afford the wait) you may spoof the program into using a different data file by renaming it as WDB.5.ALL. Simply copy one of the more detailed (lower numbered) files to a different directory under the name of "WDB.5.ALL" and run SAT from that directory. For example, if you have the SAT program on df0:, type in a CLI: cd ram: copy df0:wdb.4.all ram:wdb.5.all df0:sat SAT has many more calculations to complete than does WDB to plot a map, hence it takes quite a bit more time. Here, too, the display may appear to halt for a period during the drawing process. This is normal. When drawing is completed, the control panel will reappear on screen. ~~~~~~~~~~~~~~~~~~~~~~~~~~ INSTRUCTIONS FOR SELECT ======================= ~~~~~~~~~~~~~~~~~~~~~~~~~~ The SELECT program is used to extract lower level data segments from a higher level data file. This program enables us to put the entire WDB collection on one disk. The price to be paid is that you must extract the files named WDB.2.ALL, WDB.3.ALL and WDB.4.ALL from The Big File yourself (if you intend to use them). Note that it's not manadtory to extract these files; both WDB and SAT will work with any single data file or any combination (be sure to read the Instructions For SAT). By choosing not to extract the three intermediate files you'll lose only the speed advantage gained by not sifting through The Big File for low and medium magnification viewing. All four lower level data files (WDB.2 through .5.ALL) are merely subsets of The Big File, and SELECT can extract any one of them directly from it. Similarly, each lower level file is a subset of all higher level files, and SELECT can extract any lower level from any higher level file. Here, as elsewhere in this document, "lower level" refers to filenames which are numerically HIGHER. To use SELECT from the CLI: SELECT The level number of the source file must be numerically lower than the level number requested for the new file. The program will copy from the source file to the destination file only the records with a level number greater than or equal to the requested level number. For example, to create WDB.4.ALL from The Big File enter: SELECT WDB.1.ALL WDB.4.ALL 4 ~~~~~~~~~~~~~~~~~~~~~~~~~~ CREDITS ======= ~~~~~~~~~~~~~~~~~~~~~~~~~~ The program is the work of Mike Groshart: basic design; porting from Pascal Bob Dufford: intuition interface; speed optimization Send us further suggestions and bugs to be fixed in care of: Amiga Users of the Heartlands P.O.Box 1432, DTS Omaha, NE. 68101 E-mail: Larry's Hot Tub: 402-571-4316 [1:285/15.0@fidonet] Internet: mike.groshart@auoh.omahug.org bob.dufford@auoh.omahug.org Or route a message through Portal or BIX ID: cletus World Data Bank II for the Amiga, version 2.2 by Bob Dufford and Michael Groshart. This product uses data and code originally placed in the public domain by Fred Pospeschil and Antonio Riveria. Original coordinate data was created by the Central Intelligence Agency. Your tax dollars at work. Anyone with access to a more recent version of the coordinate data is welcome to provide it; a lot has happened to the world's political boundaries since this was first released. :-7