Tiles.CF

libtiles.tcl - Tiles Common Framework -

a micro-framework implementing common procedures
    for geo-tile processing. An extension of slippy
    map library.


 References and credits:

(1) https://wiki.tcl.tk/
    (2) https://msdn.microsoft.com/en-us/library/bb259689.aspx
    (3) http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
    (4) http://wiki.openstreetmap.org/wiki/Zoom_levels
    (5) https://en.wikipedia.org/wiki/Well-known_text
    (6) https://en.wikipedia.org/wiki/GeoJSON
    (7) http://docs.activestate.com/activetcl/8.6/tcllib/math/math_geometry.html


 Bugs:
    it looks that the current implementation of
    the slippy map library does not take into account 
    sign of lat/lon (all coordinates are positive only).
    It is fixed by functions tile2geo
getEpsilon 0 70 21

 tile2quadkey --

Convert tile coordinate (z/x/y) to quadkey. See (2) for details.


 Arguments:
        col    x tile coordinate,
        row    y tile coordinate,
        zl     zoom level.

 Results:
        quadkey

quadkey2tile --


Convert quadkey to tile coordinates (z/x/y). See (2) for details.


 Arguments:
        qkey    quadkey of tile

 Results:
        "x y zl" returns tile coordinate

tile2geo --


Convert tile coordinates (z/x/y) to lat/long. See (2) for details.
        Refinement of {::map::slippy tile 2geo} function. Order of input
        and output has been changes. 


 Arguments:
        col    x tile coordinate,
        row    y tile coordinate,
        zl     zoom level.

 Results:
        "x y" lat/long coordinates.

 See Bugs above.
trying to resolve a bug.

geo2tile --


Convert tile lat/long coordinates to tile coordinates.
        See (2) for details. Refinement of {::map::slippy geo 2tile} function.
        Order of input and output has been changes.


 Arguments:
        x     longitude,
        y     latitude,
        zl    zoom level.

 Results:
        "col row" col and row tile coordinates.

 See Bugs above.

getPixelSize --


Get tiles' pixel width in meters.


 Arguments:
        y     latitude,
        zl    zoom level.

 Results:
        width (or height) in meters.

 getEpsilon  --

Get tiles' pixel width in meters.


 Arguments:
        x     longitude,
        y     latitude,
        zl    zoom level.

 Results:
        width (or height) in meters.

 See (4).  

tile2geom --


 Arguments:
        col    x tile coordinate,
        row    y tile coordinate,
        zl     zoom level,
        type   (optional, default 0):
                 0 - EXTENT   - extent "Xmin Ymin Xmax Ymax",
                 1 - Tcl LIST - tcl polygon and central point (first and last points are same)
                     {{Xcent Ycent} {x1 y1 x2 y2 x3 y3 x4 y4 x1 y1}},
                 2 - WKT LIST - Tcl list of WKT data (See (5)) - first element is central
                     point, second element is polygon (first and last poins are same),
                 3 - GEOJSON LIST  - GeoJSON data list (first  is central point, second is polygon).

 Results:
        "x y" lat/long coordinates.

 isIn  --

Checks if any tile of one tile list is inside of
        any tileanother tiles list.
        Order of tile lists is not taken into account.


 Arguments:
        list_a     list of tile quadkeys,
        list_b     list of tile quadkeys,
        order      (optional,bool, default False) if order
                   in important. True
                   means that right need to be inside
                   or equal left.

 Results:
        0 - false, 1 - true. If a and b equal retuns true.

 isTouch  --

Checks if any tile of one tile list touches
        any tileanother tiles list.


 Arguments:
        list_a     list of tile quadkeys,
        list_b     list of tile quadkeys,

 Results:
        0 - false, 1 - true. If a and b equal returns true.

 polygonTileIntersect  --

cheks if a polygon and a tile are intersected


 Arguments:
        pol         - Tcl polygon (see (7)),
        col row zl  - tile coordinates

 Results:
        boolean

 getTilesOfPolygon  --

returns list of tiles of the intersecting a polygon.


 Arguments:
        pol     - Tcl polygon (see (7)),
        from_zl - from zoom level,
        to_zl   - (optional) if set, all tiles between defined
                  zoom levels will be returned. It has to be
                  bigger than from_zl.

 Results:
        list of tiles

 For testing/debugging:

--> https://t1.ssl.ak.dynamic.tiles.virtualearth.net/comp/ch/12023022311?mkt=en-US&it=G,BX,L,LA&shading=hill&og=88&n=z&c4w=1
 lassign "1095 732 11" col row zl
  set pol "12.55146 45.65106 12.54358 45.62229 12.57965 45.60649 12.60872 45.62890 12.59541 45.65461"