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replace shapely svg renderer because it's terribly slow

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This commit is contained in:
Laura Klünder 2017-10-20 01:34:54 +02:00
parent 518df5c247
commit fbd9b20dfd
1 changed files with 34 additions and 17 deletions
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51
src/c3nav/mapdata/utils/svg.py
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@ -2,11 +2,13 @@ import io
import math
import re
import subprocess
from itertools import chain
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.geometry import LineString, Polygon
from shapely.ops import unary_union
# import gobject-inspect, cairo and rsvg if the native rsvg SVG_RENDERER should be used
@ -127,27 +129,42 @@ class SVGImage:
# remove trailing zeros from a decimal – yes this is slow, but it greatly speeds up cairo rendering
return re.sub(r'([0-9]+)((\.[1-9])[0-9]+|\.[0-9]+)?', r'\1\3', data)
def _create_geometry(self, geometry, attribs=''):
# convert a shapely geometry into an svg xml element
def _trim_lineto(self, data):
return re.sub(r'L (-?([0-9]+)(.[0-9]+)?,(-?[0-9]+)(.[0-9]+)?) L', r'L \1 ', data)
# 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))
geometry = affine_transform(geometry, (self.scale, 0.0,
0.0, -self.scale,
-(self.left)*self.scale, (self.top)*self.scale))
element = self._trim_decimals(re.sub(r' (opacity|fill|fill-rule|stroke|stroke-width)="[^"]*"', '',
geometry.svg(0, '#FFFFFF')))
if not element.startswith('<g'):
element = '<g'+attribs+'>'+element+'</g>'
elif attribs:
element = element[:2]+attribs+element[2:]
return element
def _geometry_to_svg(self, geom):
if isinstance(geom, Polygon):
return ('<path d="' +
' '.join(('M %.1f %.1f L %s z' % (coords[0][0], coords[0][1],
' '.join(('%.1f %.1f' % (c[0], c[1])) for c in coords[1:])))
for coords in chain((geom.exterior.coords,), (ring.coords for ring in geom.interiors)))
+ '"/>')
if isinstance(geom, LineString):
return ('<path d="' +
' '.join('M %.1f %.1f L %s z' % (geom.coords[0][0], geom.coords[0][1],
' '.join(('%.1f %.1f' % (c[0], c[1])) for c in geom.coords[1:])))
+ '"/>')
try:
geoms = geom.geoms
except AttributeError:
return ''
return ''.join(self._geometry_to_svg(g) for g in geoms)
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+'>'
def register_clip_path(self, geometry):
defid = 'clip'+str(self.clip_path_i)
self.defs += '<clipPath'+self._create_geometry(geometry, ' id="'+defid+'"')[2:-2]+'clipPath>'
self.defs += self._create_geometry(geometry, ' id="'+defid+'"', tag='clipPath')
self.clip_path_i += 1
return defid