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Examples

from tilematrix import TilePyramid
from shapely.geometry import Polygon

# initialize TilePyramid
tile_pyramid = TilePyramid("geodetic")

some_polygon = Polygon([(0, 0), (1, 1), (1, 0)])
zoom = 8

Now, let's get all tile IDs (zoom, row, col) of tiles intersecting with our example geometry:

for tile in tile_pyramid.tiles_from_geom(some_polygon, zoom):
    print tile.id

output:

(8, 126, 256)
(8, 126, 257)
(8, 127, 256)
(8, 127, 257)

Use the bbox() method to get the tile bounding box geometries:

for tile in tile_pyramid.tiles_from_geom(some_polygon, zoom):
    print tile.bbox()

output:

POLYGON ((0 1.40625, 0.703125 1.40625, 0.703125 0.703125, 0 0.703125, 0 1.40625))
POLYGON ((0.703125 1.40625, 1.40625 1.40625, 1.40625 0.703125, 0.703125 0.703125, 0.703125 1.40625))
POLYGON ((0 0.703125, 0.703125 0.703125, 0.703125 0, 0 0, 0 0.703125))
POLYGON ((0.703125 0.703125, 1.40625 0.703125, 1.40625 0, 0.703125 0, 0.703125 0.703125))

We can also create a buffer around the tiles, using the pixelbuffer argument. A value of 1 will create a 1 px buffer around the tile. This depends on the initial pixel "resolution" the TilePyramid was initialized with (default 256).

for tile in tile_pyramid.tiles_from_geom(some_polygon, zoom):
    print tile.bbox(pixelbuffer=1)

output:

POLYGON ((-0.00274658203125 1.40899658203125, 0.70587158203125 1.40899658203125, 0.70587158203125 0.70037841796875, -0.00274658203125 0.70037841796875, -0.00274658203125 1.40899658203125))
POLYGON ((0.70037841796875 1.40899658203125, 1.40899658203125 1.40899658203125, 1.40899658203125 0.70037841796875, 0.70037841796875 0.70037841796875, 0.70037841796875 1.40899658203125))
POLYGON ((-0.00274658203125 0.70587158203125, 0.70587158203125 0.70587158203125, 0.70587158203125 -0.00274658203125, -0.00274658203125 -0.00274658203125, -0.00274658203125 0.70587158203125))
POLYGON ((0.70037841796875 0.70587158203125, 1.40899658203125 0.70587158203125, 1.40899658203125 -0.00274658203125, 0.70037841796875 -0.00274658203125, 0.70037841796875 0.70587158203125))

Metatiling

Metatiling is often used to combine smaller (256, 256) tiles into bigger ones. The metatiling parameter describes how many small tiles are combines into one bigger metatile. For example a metatiling parameter of 2 would combine 2x2 smaller tiles into one metatile.

You can activate metatiling by initializing a TilePyramid with a metatiling value.

# initialize TilePyramid
tile_pyramid = TilePyramid("geodetic", metatiling=2)

As the tiles are now bigger, the code we used above:

some_polygon = Polygon([(0, 0), (1, 1), (1, 0)])
zoom = 8

for tile in tile_pyramid.tiles_from_geom(some_polygon, zoom):
    print tile.bbox()

now returns just one but bigger metatile: output:

POLYGON ((1.40625 0, 1.40625 1.40625, 0 1.40625, 0 0, 1.40625 0))