Laser-Scan Ltd.

Software Product Specification

LITES2 Version 4.3

Issue 4.3 25-Feb-1994
Copyright (C) $$year Laser-Scan Ltd
Science Park, Milton Road, Cambridge, England CB4 4FY  tel: (0223) 420414
Document "LITES2 SPS"    Category "SALES - Spec"
Document Issue 1.0 Paul Hardy  12-Dec-1984
 .
 .
Document Issue 3.0      Ron Russell         23-Oct-1989
Document Issue 3.4      Paul Hardy  26-Mar-1991
Document Issue 4.0      Clarke Brunt   5-May-1992
Document Issue 4.2      Ron Russell   5-Mar-1993
Document Issue 4.3      Paul Hardy  25-Feb-1994

LITES2 PACKAGE SOFTWARE PRODUCT SPECIFICATION

DESCRIPTION

The main component of the LITES2 package is the LITES2 cartographic editor program. LITES2 is an interactive graphic and geographic display and editing program and as such forms a basic component of Laser-Scan's LAMPS mapping and GIS systems. It has been designed to be particularly suitable for work with cartographic (map) type data which normally comprises lines, areas, symbols and text but it can also be used on other types of data made up of similar features. It is possible also to display and edit raster images, either as a backdrop to the vector data, or alone.

Other components of the package are the UILMENUS and UISMENUS programs, which allow the user to create and customise hierarchical screen menu systems on windowed display screens. These are primarily intended for use with the LITES2 program, but may be used for other purposes.

The LITES2 package runs on DEC VAX and Alpha AXP series computers and will drive a variety of graphics peripherals via its internal ISO standard GKS interface.

Input vector map data is taken from Laser-Scan IFF files. These are binary files holding feature, coordinate, and attribute information in a compact form for efficient access. Coordinates are held in 32 bits (64 bits/coordinate pair) with at least 7 significant decimal digits. The magnitude of a coordinate cannot be smaller than O.29x10E-38 nor greater than 1.7x10E+38. There are least 40 million addressable values for each coordinate. Each file has an origin offset held as double precision (64-bit) values, and associated projection information, allowing accurate coverage over the whole world.

The basic element of graphical data operated on is the feature. The areal extent of features can be defined by the user; it can comprise the most simple of units - a link between two junctions - or it can extend to more complexity such as a whole building complex. Features can be grouped together into layers which are typically used to separate background from foreground, or data for different colour separations. Edit operations can therefore be carried out on features, parts of features or groups of features.

Each feature is uniquely identified by a feature serial number, and has a feature code as its primary attribute. It may also have an arbitrary number of other numeric (integer, or real), date, time, character, or textual Ancillary Codes (ACs). The coordinate points within the feature, may also have optional attributes.

FEATURE ATTRIBUTES

Numeric feature codes are in the range 0 to 32767 and are used to identify different kinds of features; examples in a cartographic application include pavement, house, parish boundary, spot height. Each feature code implies a certain graphical representation. The correspondence between feature codes and feature representation is made by looking up the feature code in a Feature Representation Table (FRT) to determine the graphical type, colour, size, symbology etc (see the FRT User's Guide and the FRTLIB Reference Manual for the design of feature coding schemes described above).

Facilities are available for definition of arbitrary groups of feature codes each with a unique name to allow easy selection of subsets of the data for display, editing or output. For example, all types of roads may be classed together in a group called "Roads" so that a given operation can be performed on all roads even though different types such as motorways, A-class roads etc. may be coded differently.

Features may have an arbitrary number of other numeric (integer, or real), date, time, character, or textual Ancillary Codes (ACs). These are commonly used for such items as "date of last edit", or "pipe diameter", or "feature height". The content, format, and description of ACs is defined in the FRT using a flexible "Ancillary Code Definition" (ACD) mechanism.

As well as X and Y coordinates, features may have a number of additional per-point attributes (up to 18 per point at present). These are defined using the ACD mechanism as for the per-feature ACs. These attributes may be of numeric (integer, or real), date, time, or character data types.

FEATURE TYPES

The validity of certain editing operations is dependent on the graphical type of the feature which is being operated on (line, symbol, text etc).

The editor supports 12 graphical types which are implied by the feature code. The graphical types catered for and their relationship with the various attributes are:-

------------------------------------------------------------------------------
                     | symbol/   | Line   |       |        |        |        |
Graphical type       | text Size | Weight | Style | Shape  | Angle  | Colour 
---------------------|-----------|--------|-------|--------|--------|--------|
Line strings      |   |   x   |   x   |    |        |   x    |
Clockwise arcs      |   |   x   |   x   |    |        |   x    |
Anticlockwise arcs   |   |   x   |   x   |    |        |   x    |
3-point arcs      |   |   x   |   x   |    |        |   x    |
Full circle      |   |   x   |   x   |    |        |   x    |
Curves       |   |   x    |   x   |    |        |   x    |
Unorientated symbols |   x  |   x   |   |    x   |        |   x    |
Orientated symbols   |   x  |   x   |   |    x   |    x   |   x    |
Scaled symbols      |   x  |   x   |   |    x   |    x   |   x    |
Text strings      |   x  |   x   |   |    x   |    x   |   x    |
Symbol strings      |   x  |   x   |   |    x   |        |   x    |
Fill areas      |  x  |   x   |   x   |    x   |    x   |   x    |
------------------------------------------------------------------------------

FACILITIES

The following facilities are included in the LITES2 software. Certain of these are licensed as options, and these are marked below as [OPTION]. Further details of facilities can be found in the LITES2 USERS GUIDE and the LITES2 REFERENCE MANUAL. The facilities described below are subject to continual development and are likely to change at short notice.

PREREQUISITES

COMPUTER HARDWARE PREREQUISITES

GRAPHICS PERIPHERAL PREREQUISITES

LITES2 is usually used with a Laser-Scan supported graphics device, currently one of:

GRAPHICAL INPUT DEVICE PREREQUISITES

The following input device may optionally be used with LITES2 for input of map coordinates, or commands from a menu:

This list reflects a set of currently available hardware options, but the graphics devices are under constant review in the light of new products and customer requirements.

SOFTWARE PREREQUISITES

OpenVMS VAX Version 5.5-2, or OpenVMS AXP Version 1.5 (or higher version, assuming continued upwards compatibility by DEC) concurrently with other interactive and batch processes.

DEC windowing software is required for the VAXstation or DECstation displays, either VAX Workstation Software layered product (VWS) or DECwindows Motif layered product (the latter is required for X-terminals). The "VMS DECwindows Developers Kit for Motif" is not adequate.

The MAPPING package is a LITES2 software prerequisite. As part of this package Laser-Scan provide the necessary interface libraries for data files (IFF files) and data representation information (FRT files).

The MATRIX package is a LITES2 software prerequisite if the Raster Image option is required. This provides interface libraries and utilities to manipulate the image files.

The LSRRASTER package is a LITES2 software prerequisite if the Raster Image option is required and LSR files are to be manipulated. This provides interface libraries to manipulate the image files.

The PLOTTING package is a LITES2 software prerequisite if the hardcopy plotting option is required.

LITES2 would normally be used in conjunction with the IMP map processing package and the FPP plotting program which forms the main component of the PLOTTING package.

Laser-Scan's VTRAK automated digitising package is recommended for volume input of documents.

GROWTH CONSIDERATIONS

The minimum hardware and software requirements for any future version of this product may be different from the minimum requirements for the current version.

SUPPORT LEVEL

LITES2 is a fully supported Laser-Scan standard software product.