1map::slippy(n)                 Mapping utilities                map::slippy(n)
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NAME

8       map::slippy - Common code for slippy based map packages
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SYNOPSIS

11       package require Tcl  8.4
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13       package require Tk  8.4
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15       package require map::slippy  ?0.2?
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17       ::map::slippy length level
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19       ::map::slippy tiles level
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21       ::map::slippy tile size
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23       ::map::slippy tile valid tile levels ?msgvar?
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25       ::map::slippy geo 2tile geo
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27       ::map::slippy geo 2point geo
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29       ::map::slippy tile 2geo tile
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31       ::map::slippy tile 2point tile
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33       ::map::slippy point 2geo point
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35       ::map::slippy point 2tile point
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DESCRIPTION

40       This  package  provides  a number of methods doing things needed by all
41       types of slippy-based map packages.
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API

44       ::map::slippy length level
45              This method returns the width/height of a  slippy-based  map  at
46              the  specified  zoom  level, in pixels. This is, in essence, the
47              result of
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49                   expr { [tiles $level] * [tile size] }
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52       ::map::slippy tiles level
53              This method returns the width/height of a  slippy-based  map  at
54              the specified zoom level, in tiles.
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56       ::map::slippy tile size
57              This method returns the width/height of a tile in a slippy-based
58              map, in pixels.
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60       ::map::slippy tile valid tile levels ?msgvar?
61              This method checks whether tile described  a  valid  tile  in  a
62              slippy-based map containing that many zoom levels. The result is
63              a boolean value, true if the tile is valid, and false otherwise.
64              For  the  latter a message is left in the variable named by msg‐
65              var, should it be specified.
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67              A tile identifier as stored in tile is a  list  containing  zoom
68              level,  tile  row,  and  tile column, in this order. The command
69              essentially checks this, i.e. the syntax, that the zoom level is
70              between  0  and  "levels-1", and that the row/col information is
71              within the boundaries for the zoom level, i.e.  0  ...   "[tiles
72              $zoom]-1".
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74       ::map::slippy geo 2tile geo
75              Converts  a  geographical  location at a zoom level (geo, a list
76              containing zoom level, latitude, and longitude, in  this  order)
77              to  a tile identifier (list containing zoom level, row, and col‐
78              umn) at that level.
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80       ::map::slippy geo 2point geo
81              Converts a geographical location at a zoom level  (geo,  a  list
82              containing  zoom  level, latitude, and longitude, in this order)
83              to a pixel position (list containing zoom level, y,  and  x)  at
84              that level.
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86       ::map::slippy tile 2geo tile
87              Converts  a tile identifier at a zoom level (tile, list contain‐
88              ing zoom level, row, and  column)  to  a  geographical  location
89              (list  containing  zoom  level, latitude, and longitude, in this
90              order) at that level.
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92       ::map::slippy tile 2point tile
93              Converts a tile identifier at a zoom level (tile,  a  list  con‐
94              taining  zoom  level, row, and column, in this order) to a pixel
95              position (list containing zoom level, y, and x) at that level.
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97       ::map::slippy point 2geo point
98              Converts a pixel position at a zoom level (point, list  contain‐
99              ing  zoom level, y, and x) to a geographical location (list con‐
100              taining zoom level, latitude, and longitude, in this  order)  at
101              that level.
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103       ::map::slippy point 2tile point
104              Converts  a  pixel  position at a zoom level (point, a list con‐
105              taining zoom level, y, and x, in this order) to a  tile  identi‐
106              fier  (list  containing  zoom  level,  row,  and column) at that
107              level.
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REFERENCES

110       [1]    http://wiki.openstreetmap.org/wiki/Main_Page
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KEYWORDS

113       geodesy, geography, latitute, location, longitude, map, slippy, zoom
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117map                                   0.2                       map::slippy(n)