MAP(6) Games Manual MAP(6)
NAME
map - digitized map formats
DESCRIPTION
Files used by map(7) are a sequence of structures of the form:
struct {
signed char patchlatitude;
signed char patchlongitude;
short n;
union {
struct {
short latitude;
short longitude;
} point[n];
struct {
short latitude;
short longitude;
struct {
signed char latdiff;
signed char londiff;
} point[-n];
} highres;
} segment;
};
where short stands for 16-bit integers and there is no padding within or between structs. Shorts are stored in little-endian order, low
byte first. To assure portability, map accesses them bytewise.
Fields and tell to what 10-degree by 10-degree patch of the earth's surface a segment belongs. Their values range from -9 to 8 and from
-18 to 17, respectively, and indicate the coordinates of the southeast corner of the patch in units of 10 degrees.
Each segment of |n| points is connected; consecutive segments are not necessarily related. Latitude and longitude are measured in units of
0.0001 radian. If n is negative, then differences to the first and succeeding points are measured in units of 0.00001 radian. Latitude is
counted positive to the north and longitude positive to the west.
The patches are ordered lexicographically by then A printable index to the first segment of each patch in a file named data is kept in an
associated file named data.x. Each line of an index file contains and the byte position of the patch in the map file. Both the map file
and the index file are ordered by patch latitude and longitude.
SEE ALSO
map(7)
The data comes from the World Data Bank I and II and U.S. Government sources: the Census Bureau, Geological Survey, and CIA.
MAP(6)
Check Out this Related Man Page
map::slippy(n) Mapping utilities map::slippy(n)
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NAME
map::slippy - Common code for slippy based map packages
SYNOPSIS
package require Tcl 8.4
package require Tk 8.4
package require map::slippy ?0.3?
::map::slippy length level
::map::slippy tiles level
::map::slippy tile size
::map::slippy tile valid tile levels ?msgvar?
::map::slippy geo 2tile geo
::map::slippy geo 2point geo
::map::slippy tile 2geo tile
::map::slippy tile 2point tile
::map::slippy point 2geo point
::map::slippy point 2tile point
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DESCRIPTION
This package provides a number of methods doing things needed by all types of slippy-based map packages.
API
::map::slippy length level
This method returns the width/height of a slippy-based map at the specified zoom level, in pixels. This is, in essence, the result
of
expr { [tiles $level] * [tile size] }
::map::slippy tiles level
This method returns the width/height of a slippy-based map at the specified zoom level, in tiles.
::map::slippy tile size
This method returns the width/height of a tile in a slippy-based map, in pixels.
::map::slippy tile valid tile levels ?msgvar?
This method checks whether tile described a valid tile in a slippy-based map containing that many zoom levels. The result is a bool-
ean value, true if the tile is valid, and false otherwise. For the latter a message is left in the variable named by msgvar, should
it be specified.
A tile identifier as stored in tile is a list containing zoom level, tile row, and tile column, in this order. The command essen-
tially checks this, i.e. the syntax, that the zoom level is between 0 and "levels-1", and that the row/col information is within the
boundaries for the zoom level, i.e. 0 ... "[tiles $zoom]-1".
::map::slippy geo 2tile geo
Converts a geographical location at a zoom level (geo, a list containing zoom level, latitude, and longitude, in this order) to a
tile identifier (list containing zoom level, row, and column) at that level.
::map::slippy geo 2point geo
Converts a geographical location at a zoom level (geo, a list containing zoom level, latitude, and longitude, in this order) to a
pixel position (list containing zoom level, y, and x) at that level.
::map::slippy tile 2geo tile
Converts a tile identifier at a zoom level (tile, list containing zoom level, row, and column) to a geographical location (list con-
taining zoom level, latitude, and longitude, in this order) at that level.
::map::slippy tile 2point tile
Converts a tile identifier at a zoom level (tile, a list containing zoom level, row, and column, in this order) to a pixel position
(list containing zoom level, y, and x) at that level.
::map::slippy point 2geo point
Converts a pixel position at a zoom level (point, list containing zoom level, y, and x) to a geographical location (list containing
zoom level, latitude, and longitude, in this order) at that level.
::map::slippy point 2tile point
Converts a pixel position at a zoom level (point, a list containing zoom level, y, and x, in this order) to a tile identifier (list
containing zoom level, row, and column) at that level.
REFERENCES
[1] http://wiki.openstreetmap.org/wiki/Main_Page
KEYWORDS
geodesy, geography, latitute, location, longitude, map, slippy, zoom
map 0.3 map::slippy(n)