NAME

road, gps − road map of the United States

SYNOPSIS

­games/road [ ­-g ] [ ­-s ­scale ]
­games/gps

DESCRIPTION

­Road displays a road map centered around some specified place in the United States.  The data comes from the Census Bureau Tiger Database.  The map is drawn in three shades of grey.  Light grey is used for water features such as rivers, streams and lakes.  Dark grey is used for railroads and airports.  Black is used for roads.  On terminals with ldepth zero, all shades appear black. 

Without options, the center of the map is the latitude and longitude specified in the file /lib/sky/here.  If the ­-g option is given, the center of the map will be the latitude and longitude specified by continually monitoring the end of the file /tmp/gpslog.  This file is written by the GPS satellite receiver program gps. With this option, and with ­gps running, ­road becomes a moving map display suitable for cars or planes. 

Keyboard commands

­s number
sets the scale of the map to number. The ­number can be prefixed with ­+ or ­- to increase/decrease the current scale.  Scale 6 is about one mile across the screen and scale 10 is about ten miles across.  Scales 1 through 10 are drawn with maximum detail showing all roads, trails, rivers, streams and airports.  Scales 11 through 14 show highways, rivers, airports and county boundaries.  Scales 15 through 20 show interstate highways and state boundaries. 

/regexp
All features labeled by text matching the regular expression are highlighted.

­p place
centers the map at the specified place. Usually the place must have the associated state code, (eg murrayhill,nj) but places like ­lax and ­ewr are also known. 

­l latitude longitude
centers the map at the specified coordinate.

g toggles the ­-g option described above. 

­q Exit. 

Mouse button commands

Button 1
displays the text of the ­line nearest the cursor.  Normally this is the name of a street or river. 

Button 2
displays the text of the ­place nearest the cursor.  Normally this is a town. 

Button 3
centers the display on the cursor position.

­Gps reads ­/dev/eia0 assumed connected to a Garmin GPS-55 satellite receiver and writes the current location on the end of the file /tmp/gpslog.  It is intended to be used with mobile PC’s. 

FILES

­/lib/roads/LLLL/LLLLGGGG.h
scale 1-10 database files where ­LLLL is the latitude multiplied by 5 and ­GGGG is the longitude multiplied by 5. 

­/lib/roads/LLL/LLLGGG.h
scale 11-14 database files where ­LLL is the latitude multiplied by 1 and ­GGG is the longitude multiplied by 1. 

­/lib/roads/LL/LLGG.h
scale 15-20 database files where ­LL is the latitude multiplied by 0.2 and ­GG is the longitude multiplied by 0.2. 

­/lib/roads/place
­/lib/roads/place.local are the translations between place names and locations.  These files must be sorted. 

­/lib/sky/here
default starting map center.

­/tmp/gpslog
moving map location.

SOURCE

­/sys/src/games/road
­/sys/src/games/gps

Plan 9  —  April 04, 1995