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improve _create_geometry performance by replacing affine_transform with numpy

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This commit is contained in:
Laura Klünder 2017-10-20 11:55:17 +02:00
parent 1b3fab8993
commit bf7ba02065
1 changed files with 10 additions and 12 deletions
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22
src/c3nav/mapdata/utils/svg.py
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@ -4,10 +4,11 @@ import re
import subprocess
from itertools import chain
import numpy as np
from django.conf import settings
from django.core.checks import Error, register
from PIL import Image
from shapely.affinity import affine_transform, translate
from shapely.affinity import translate
from shapely.geometry import LineString, Polygon
from shapely.ops import unary_union
@ -135,12 +136,17 @@ class SVGImage:
def _geometry_to_svg(self, geom):
if isinstance(geom, Polygon):
return ('<path d="' +
' '.join((('M %.1f %.1f L'+(' %.1f %.1f'*(len(ring.coords)-1))) % tuple(ring.ctypes))
' '.join((('M %.1f %.1f L'+(' %.1f %.1f'*(len(ring.coords)-1))) %
tuple((np.array(ring)
* np.array((self.scale, -self.scale))
+ np.array((-self.left*self.scale, self.top*self.scale))).flatten()))
for ring in chain((geom.exterior,), geom.interiors))
+ '"/>').replace('.0 ', ' ')
if isinstance(geom, LineString):
return (('<path d="M %.1f %.1f L'+(' %.1f %.1f'*(geom.coords-1))+'"/>') %
tuple(geom.ctypes)).replace('.0 ', ' ')
tuple((np.array(geom)
* np.array((self.scale, -self.scale))
+ np.array((-self.left*self.scale, self.top*self.scale))).flatten())).replace('.0 ', ' ')
try:
geoms = geom.geoms
except AttributeError:
@ -149,15 +155,7 @@ class SVGImage:
def _create_geometry(self, geometry, attribs='', tag='g'):
# convert a shapely geometry into an svg xml element
return '<'+tag+attribs+'>'+self._geometry_to_svg(
# scale and move the object into position, this is equivalent to:
# geometry = translate(geometry, xoff=0-self.left, yoff=0-self.bottom)
# geometry = scale(geometry, xfact=1, yfact=-1, origin=(self.width / 2, self.height / 2))
# geometry = scale(geometry, xfact=self.scale, yfact=self.scale, origin=(0, 0))
affine_transform(geometry, (self.scale, 0.0,
0.0, -self.scale,
-(self.left) * self.scale, (self.top) * self.scale))
)+'</'+tag+'>'
return '<'+tag+attribs+'>'+self._geometry_to_svg(geometry)+'</'+tag+'>'
def register_clip_path(self, geometry):
defid = 'clip'+str(self.clip_path_i)