-
Notifications
You must be signed in to change notification settings - Fork 47
/
encoder.py
266 lines (211 loc) · 9.91 KB
/
encoder.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
from numbers import Number
from shapely.geometry import shape as shapely_shape
from shapely.geometry.base import BaseGeometry
from shapely.geometry.multipolygon import MultiPolygon
from shapely.geometry.polygon import Polygon, orient
from shapely.ops import transform
from shapely.wkb import loads as load_wkb
from shapely.wkt import loads as load_wkt
from mapbox_vector_tile.geom_encoder import GeometryEncoder
from mapbox_vector_tile.Mapbox import vector_tile_pb2 as vector_tile
from mapbox_vector_tile.polygon import make_it_valid
from mapbox_vector_tile.utils import get_encode_options
def on_invalid_geometry_raise(shape):
raise ValueError(f"Invalid geometry: {shape.wkt}")
def on_invalid_geometry_ignore(shape):
return None
def on_invalid_geometry_make_valid(shape):
return make_it_valid(shape)
class VectorTile:
def __init__(self, default_options=None):
self.tile = vector_tile.tile()
self.default_options = default_options
self.layer = None
self.layer_options = None
self.key_idx = 0
self.val_idx = 0
self.seen_keys_idx = {}
self.seen_values_idx = {}
self.seen_values_bool_idx = {}
self.seen_layer_names = set()
def add_layer(self, name, features, options=None):
if not name:
raise ValueError(f"A layer name can not be empty. {name!r} was provided.")
if name in self.seen_layer_names:
raise ValueError(f"The layer name {name!r} already exists in the vector tile.")
self.seen_layer_names.add(name)
self.layer = self.tile.layers.add()
self.layer_options = get_encode_options(layer_options=options, default_options=self.default_options)
self.layer.name = name
self.layer.version = 2
self.layer.extent = self.layer_options["extents"]
self.key_idx = 0
self.val_idx = 0
self.seen_keys_idx = {}
self.seen_values_idx = {}
self.seen_values_bool_idx = {}
for feature in features:
# skip missing or empty geometries
geometry_spec = feature.get("geometry")
if geometry_spec is None:
continue
shape = self._load_geometry(geometry_spec)
if shape is None:
raise NotImplementedError("Can't do geometries that are not wkt, wkb, or shapely geometries")
if shape.is_empty:
continue
if self.layer_options["quantize_bounds"]:
shape = self.quantize(shape)
if self.layer_options["check_winding_order"]:
shape = self.enforce_winding_order(shape)
if shape is not None and not shape.is_empty:
self.add_feature(feature, shape)
def enforce_winding_order(self, shape, n_try=1):
if shape.geom_type == "MultiPolygon":
# If we are a multipolygon, we need to ensure that the winding orders of the constituent polygons are
# correct. In particular, the winding order of the interior rings need to be the opposite of the exterior
# ones, and all interior rings need to follow the exterior one. This is how the end of one polygon and
# the beginning of another are signaled.
shape = self.enforce_multipolygon_winding_order(shape=shape, n_try=n_try)
elif shape.geom_type == "Polygon":
# Ensure that polygons are also oriented with the appropriate winding order. Their exterior rings must
# have a clockwise order, which is translated into a clockwise order in MVT's tile-local coordinates with
# the Y axis in "screen" (i.e: +ve down) configuration. Note that while the Y axis flips, we also invert
# the Y coordinate to get the tile-local value, which means the clockwise orientation is unchanged.
shape = self.enforce_polygon_winding_order(shape=shape, n_try=n_try)
# other shapes just get passed through
return shape
def quantize(self, shape):
minx, miny, maxx, maxy = self.layer_options["quantize_bounds"]
extents = self.layer_options["extents"]
def fn(x, y, z=None):
xfac = extents / (maxx - minx)
yfac = extents / (maxy - miny)
x = xfac * (x - minx)
y = yfac * (y - miny)
return round(x), round(y)
return transform(fn, shape)
def handle_shape_validity(self, shape, n_try):
if shape.is_valid:
return shape
if n_try >= self.layer_options["max_geometry_validate_tries"]:
# ensure that we don't recurse indefinitely with an invalid geometry handler that doesn't validate
# geometries
return None
if self.layer_options["on_invalid_geometry"]:
shape = self.layer_options["on_invalid_geometry"](shape)
if shape is not None and not shape.is_empty:
# This means that we have a handler that might have altered the geometry. We'll run through the process
# again, but keep track of which attempt we are on to terminate the recursion.
shape = self.enforce_winding_order(shape=shape, n_try=n_try + 1)
return shape
def enforce_multipolygon_winding_order(self, shape, n_try):
assert shape.geom_type == "MultiPolygon"
parts = []
for part in shape.geoms:
part = self.enforce_polygon_winding_order(shape=part, n_try=n_try)
if part is not None and not part.is_empty:
if part.geom_type == "MultiPolygon":
parts.extend(part.geoms)
else:
parts.append(part)
if not parts:
return None
oriented_shape = parts[0] if len(parts) == 1 else MultiPolygon(parts)
oriented_shape = self.handle_shape_validity(oriented_shape, n_try)
return oriented_shape
def enforce_polygon_winding_order(self, shape, n_try):
assert shape.geom_type == "Polygon"
def fn(point):
x, y = point
return round(x), round(y)
exterior = self.apply_map(fn, shape.exterior.coords)
rings = None
if len(shape.interiors) > 0:
rings = [self.apply_map(fn, ring.coords) for ring in shape.interiors]
sign = 1.0 if self.layer_options["y_coord_down"] else -1.0
oriented_shape = orient(Polygon(exterior, rings), sign=sign)
oriented_shape = self.handle_shape_validity(oriented_shape, n_try)
return oriented_shape
@staticmethod
def apply_map(fn, x):
return list(map(fn, x))
def _load_geometry(self, geometry_spec):
if isinstance(geometry_spec, BaseGeometry):
geom = geometry_spec
elif isinstance(geometry_spec, dict):
geom = shapely_shape(geometry_spec)
else:
try:
geom = load_wkb(geometry_spec)
except Exception:
try:
geom = load_wkt(geometry_spec)
except Exception:
return None
if self.layer_options["transformer"] is None:
return geom
else:
return transform(self.layer_options["transformer"], geom)
def add_feature(self, feature, shape):
geom_encoder = GeometryEncoder(self.layer_options["y_coord_down"], self.layer_options["extents"])
geometry = geom_encoder.encode(shape)
feature_type = self._get_feature_type(shape)
if len(geometry) == 0:
# Don't add geometry if it's too small
return
f = self.layer.features.add()
fid = feature.get("id")
if fid is not None and isinstance(fid, Number) and fid >= 0:
f.id = fid
# properties
properties = feature.get("properties")
if properties is not None:
self._handle_attr(self.layer, f, properties)
f.type = feature_type
f.geometry.extend(geometry)
def _get_feature_type(self, shape):
if shape.geom_type == "Point" or shape.geom_type == "MultiPoint":
return self.tile.Point
elif shape.geom_type == "LineString" or shape.geom_type == "MultiLineString":
return self.tile.LineString
elif shape.geom_type == "Polygon" or shape.geom_type == "MultiPolygon":
return self.tile.Polygon
elif shape.geom_type == "GeometryCollection":
raise ValueError("Encoding geometry collections not supported")
else:
raise ValueError(f"Cannot encode unknown geometry type: {shape.geom_type}")
@staticmethod
def _chunker(seq, size):
return [seq[pos : pos + size] for pos in range(0, len(seq), size)]
@staticmethod
def _can_handle_key(k):
return isinstance(k, str)
@staticmethod
def _can_handle_val(v):
return isinstance(v, (str, bool, int, float))
@classmethod
def _can_handle_attr(cls, k, v):
return cls._can_handle_key(k) and cls._can_handle_val(v)
def _handle_attr(self, layer, feature, props):
for k, v in props.items():
if self._can_handle_attr(k, v):
if k not in self.seen_keys_idx:
layer.keys.append(k)
self.seen_keys_idx[k] = self.key_idx
self.key_idx += 1
feature.tags.append(self.seen_keys_idx[k])
values_idx = self.seen_values_bool_idx if isinstance(v, bool) else self.seen_values_idx
if v not in values_idx:
values_idx[v] = self.val_idx
self.val_idx += 1
val = layer.values.add()
if isinstance(v, bool):
val.bool_value = v
elif isinstance(v, str):
val.string_value = v
elif isinstance(v, int):
val.int_value = v
elif isinstance(v, float):
val.double_value = v
feature.tags.append(values_idx[v])