def filterByViewport(self, geometry):
try:
return geometry.intersection(self.viewportRect)
except shapely.geos.TopologicalError:
return False
def mask_geometries_by_geometries(
geometries: List[geometry.base.BaseGeometry],
masking_geometries: List[geometry.base.BaseGeometry],
):
masked_geometries = []
for geometry in geometries:
for mask in masking_geometries:
geometry = geometry.intersection(mask)
if geometry.length > 0.0:
masked_geometries.append(geometry)
return masked_geometries
def _index_shapes(shapes, cell_key):
"""Spatially index other masks to cell mask.
Parameters
----------
shapes : dict
Dictionary of GeoDataFrames.
Returns
-------
indexed_shapes : GeoDataFrame
Each column is
"""
cell_shapes = shapes[cell_key]
indexed_shapes = cell_shapes.copy()
for shape_name, shape in shapes.items():
# Don't index cell to itself
if shape_name == "cell":
continue
# For each cell, get all overlapping shapes
geometry = gpd.sjoin(shape,
cell_shapes,
how="left",
op="intersects",
rsuffix="cell").dropna()
# Calculate fraction overlap for each pair SLOW
geometry["fraction_overlap"] = (geometry.intersection(
cell_shapes.loc[geometry["index_cell"]], align=False).area /
geometry.area)
# Keep shape that overlaps with cell_shapes the most
geometry = (geometry.sort_values(
"fraction_overlap",
ascending=False).drop_duplicates("index_cell").set_index(
"index_cell").reindex(cell_shapes.index)["geometry"])
geometry.name = f"{shape_name}_shape"
# Add indexed shapes as new column in GeoDataFrame
indexed_shapes[f"{shape_name}_shape"] = geometry
# Cells are rows, intersecting shape sets are columns
indexed_shapes = indexed_shapes.rename(columns={"geometry": "cell_shape"})
indexed_shapes.index = indexed_shapes.index.astype(str)
return indexed_shapes
def tile(geometry, chunk_dim_meters=chunk_dim_meters):
# NOTE: these are not aligned to tile coordinates
minx, miny, maxx, maxy = geometry.bounds
tiled_polys = []
y = miny
while y < maxy:
x = minx
endy = y + chunk_dim_meters
while x < maxx:
endx = x + chunk_dim_meters
tile_bounds = shapely.geometry.box(x, y, endx, endy)
tiled_poly = geometry.intersection(tile_bounds)
if not tiled_poly.is_empty:
tiled_polys.append(tiled_poly)
x += chunk_dim_meters
y += chunk_dim_meters
return tiled_polys
def filterByViewport(self, geometry):
try:
return geometry.intersection(self.viewportRect)
except shapely.geos.TopologicalError:
return False
def _katana(geometry, threshold, count=0, maxcount=250):
"""
From https://snorfalorpagus.net/blog/2016/03/13/splitting-large-polygons-for-faster-intersections/
Split a Polygon into two parts across it's shortest dimension
Copyright (c) 2016, Joshua Arnott
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
"""
bounds = geometry.bounds
width = bounds[2] - bounds[0]
height = bounds[3] - bounds[1]
if max(width, height) <= threshold or count == maxcount:
# either the polygon is smaller than the threshold, or the maximum
# number of recursions has been reached
return [geometry]
if height >= width:
# split left to right
a = box(bounds[0], bounds[1], bounds[2], bounds[1]+height/2)
b = box(bounds[0], bounds[1]+height/2, bounds[2], bounds[3])
else:
# split top to bottom
a = box(bounds[0], bounds[1], bounds[0]+width/2, bounds[3])
b = box(bounds[0]+width/2, bounds[1], bounds[2], bounds[3])
result = []
for d in (a, b,):
c = geometry.intersection(d)
if not isinstance(c, GeometryCollection):
c = [c]
for e in c:
if isinstance(e, (Polygon, MultiPolygon)):
result.extend(_katana(e, threshold, count+1, maxcount))
if count > 0:
return result
# convert multipart into singlepart
final_result = []
for g in result:
if isinstance(g, MultiPolygon):
final_result.extend(g)
else:
final_result.append(g)
return final_result
