|
|
Plotting your Web site visitors on a map
|
|
map::slippy(n) Mapping utilities map::slippy(n) __________________________________________________________________________________________________________________________________________________ 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 _________________________________________________________________ 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)
