
___________________

EarthMap user guide
___________________


User, please note
=================

EarthMap is Freeware, i.e. it is free software, but not public domain.

Copyright notice
================

The copyrights (c) of this program belong to John Kortink. All rights are
reserved.

You may not make changes to this program (except for documented configuration
changes). If you distribute it, you may only distribute the complete and
unchanged original copy (as you first received it). You may distribute this
program freely, but must obtain written permission from me if it is to be
distributed as part of, or alongside, any product that is meant to generate
profits. This program is provided 'as is'. Fitness of this program for any
particular purpose is not implied. Using it is entirely at your own risk.


//
//
// Introduction
//
//

Features :

- Draws 'maps' of Earth, using a public domain database containing 5,719,617
  line segments that describe the coordinates and outline the shapes of a
  number of natural and man-made features (including coastlines, country
  borders, rivers, lakes, canals, glaciers, etc.).

- Provides an extensive array of viewing facilities, including pan, zoom and
  longitude/latitude entry.

- Can save any 'view' to a Draw file.

The database used by EarthMap is the public domain 'CIA World Data Bank II'. It
is not an integral part of EarthMap (due to its size), but can be downloaded
from (e.g.) :

http://sepwww.stanford.edu/ftp/World_Map/

(roughly 8 MB of data). Download all the Map.* files, append them to single
files (e.g. append Map.africa.tar.gz.0, .1 and .2 to africa.tar.gz), 'ungzip'
and 'untar' them, and rename the resulting files as shown in the !EarthMap.Maps
directory.

Although having the full database 'online' is highly recommended, EarthMap can
make do with any subset of the database files (including none, although roaming
a completely black world will probably be less than inspiring to most people).
If a particular database file is absent, or its contents are not recognized,
the corresponding part of the globe will simply not show in the view window.


//
//
// Compatibility
//
//

EarthMap should be compatible with :

- RISC OS 3.1 and later
- ARM 2 and later processors (26-bit architectures only)


//
//
// Using EarthMap
//
//

Start !EarthMap. Click MENU on EarthMap's iconbar icon.

EarthMap's iconbar menu pops up, showing the following entries :

- 'Info' and 'Quit' require no explanation.
- 'Choices' gives access to the 'Choices' menu.
- 'Save' gives access to the Draw file save window.
- Clicking 'Control ...' opens the 'Control' window.
- Clicking 'Detail ...' opens the 'Detail' window.
- Clicking 'Cache ...' opens the 'Cache' window.

Clicking either SELECT or ADJUST on EarthMap's iconbar icon will open the View
window (or, if it is already open, redraw it).

The menu and windows mentioned are discussed in detail below.


//
//
// The View window
//
//

This is your window on the globe (henceforth referred to as 'the view').

There are several ways to pan and zoom the view :

- Double-clicking SELECT or ADJUST inside the view pans the view so that the
  location clicked on is at the center of the new view.

- Double-clicking SELECT or ADJUST inside the view while pressing a CTRL, SHIFT
  or ALT key zooms the view (SELECT = zoom in, ADJUST = zoom out). Also, the
  view is panned so that the location clicked on is at the center of the new
  view. The selected zoom factor is 4, 2 or 1.5 when pressing an ALT, SHIFT or
  CTRL key respectively.

- Dragging a 'box' around an area of interest inside the view pans and zooms
  the view so that the selected area (at its maximum size) is entirely visible
  inside the new view, and the center of the selected area is at the center of
  the new view.

- Using the Control window, 'Coordinates' section. Enter the required longitude
  and latitude of the new view center and click on the 'Go to' button.

There are a couple of important things to note about the view :

- The 'world' basically consists of a rectangle stretching from -180 to +180
  degrees longitude (in horizontal direction) and from -90 to +90 degrees
  latitude (in vertical direction). The view window shows this 'world' in
  'wraparound' mode (to simulate a globe), which effectively means that -180
  and +180 degrees longitude appear adjacent in the view, as do -90 and +90
  degrees latitude. While the 'longitude wrap' is correct, the 'latitude wrap'
  obviously isn't (the North and South pole are not adjacent). However, this
  way of displaying the world allows much more freedom when panning the view,
  in addition to having (limited) entertainment value.

- As there is no real 'end' to the globe, the result of dragging the View
  window's scroll bars is slightly unusual. Due to the way the 'wraparound'
  feature is implemented, the view window is actually a view on not a single
  world, but on a two dimensional array of identical worlds, with (at maximum
  zoom) only a single world visible at any one time. Therefore, dragging the
  scroll bars results in pretty coarse panning. Note, however, that clicking
  the scroll bar 'arrows' is a good alternative in this case.


//
//
// The 'Control' window
//
//

You will find two sections in this window, 'Coordinates' and 'Draw file'.

The 'Coordinates' section provides a precise longitude/latitude control (i.e.
allows specification of coordinates in degrees, minutes and seconds). Clicking
'Get' automatically enters the coordinates of the current center of the View
window. Clicking 'Go to' recenters the View window on the specified coordinates
(refer to 'The View window' for more details).

The 'Draw file' section allows you to specify the page size that is saved in
Draw files (refer to 'The Draw file save window' for more details). The default
of 8.27 x 11.69 inches is standard A4 size.


//
//
// The 'Detail' window
//
//

The database contains information about several different Earth features (also
referred to as details). Every detail belongs to a detail group. Every detail
group ('Boundary', 'Coast, islands & lakes', 'Rivers' and 'USA state lines') is
stored in a seperate database file (the files ending in 'bdy', 'cil', 'riv' and
'pby' respectively).

Every detail has an on/off flag. If a detail is 'on', it is displayed in the
View window (and saved in Draw files). If a detail is 'off', it is ignored
completely (as if it were not present in the database). The 'All on' and 'All
off' buttons may be used to switch on/off all the details in a detail group.

Every detail has a colour. This is the colour used to render the detail in the
View window (and in Draw files). If your machine runs RISC OS 3.5 or later the
detail colours can be changed by clicking on the colour box, which will pop up
a standard 'colour picker' window. Under RISC OS versions before 3.5 detail
colours cannot be changed.


//
//
// The 'Cache' window
//
//

Every database file has a cache flag. If a cache flag is 'on', the database
file is cached in memory. If a cache flag is 'off', the database file is not
cached. The 'All on' and 'All off' buttons may be used to switch on/off all the
cache flags.

EarthMap needs continuous access to the database files, so the speed at which
these can be accessed is quite important. If a database file is cached, it can
be accessed very quickly, albeit at the expense of some memory. If you have the
memory to spare, it is a good idea to cache all the database files (roughly 13
MB is required to do this).


//
//
// The Draw file save window
//
//

This allows you to save what is currently visible in the View window as a Draw
file. Simply enter a leaf name and drag the Draw file icon to a Filer window.

The page size saved in the Draw file may be specified via a setting in the
Control window (refer to 'The Control window' for more details).


//
//
// The 'Choices' menu
//
//

In this menu you can manipulate EarthMap's 'choices'.

- 'Save' will save the current choices.
- 'Load' will load the saved choices.
- 'Default' will load the default choices.
- 'Kill' will discard the saved choices.

When EarthMap starts up it loads the saved choices, or the default choices if
no choices were saved.

The choices consist of the detail flags and colours (available from the Detail
window), the cache flags (available from the Cache window) and the Draw file
page size (available from the Control window).


//
//
// Epilogue
//
//

Updates of EarthMap (if any appear) will be made available by (in order of
preference) :

- World Wide Web : visit web.inter.nl.net/users/J.Kortink
- Electronic mail : email kortink@inter.nl.net

Enjoy !


John Kortink



