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
|
#! /usr/bin/env python
#
# Copyright 2015 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Converts a cubic bezier curve to a quadratic spline with
exactly two off curve points.
"""
import numpy
from numpy import array,cross,dot
from fontTools.misc import bezierTools
from robofab.objects.objectsRF import RSegment
def replaceSegments(contour, segments):
while len(contour):
contour.removeSegment(0)
for s in segments:
contour.appendSegment(s.type, [(p.x, p.y) for p in s.points], s.smooth)
def calcIntersect(a,b,c,d):
numpy.seterr(all='raise')
e = b-a
f = d-c
p = array([-e[1], e[0]])
try:
h = dot((a-c),p) / dot(f,p)
except:
print a,b,c,d
raise
return c + dot(f,h)
def simpleConvertToQuadratic(p0,p1,p2,p3):
p = [array(i.x,i.y) for i in [p0,p1,p2,p3]]
off = calcIntersect(p[0],p[1],p[2],p[3])
# OFFCURVE_VECTOR_CORRECTION = -.015
OFFCURVE_VECTOR_CORRECTION = 0
def convertToQuadratic(p0,p1,p2,p3):
# TODO: test for accuracy and subdivide further if needed
p = [(i.x,i.y) for i in [p0,p1,p2,p3]]
# if p[0][0] == p[1][0] and p[0][0] == p[2][0] and p[0][0] == p[2][0] and p[0][0] == p[3][0]:
# return (p[0],p[1],p[2],p[3])
# if p[0][1] == p[1][1] and p[0][1] == p[2][1] and p[0][1] == p[2][1] and p[0][1] == p[3][1]:
# return (p[0],p[1],p[2],p[3])
seg1,seg2 = bezierTools.splitCubicAtT(p[0], p[1], p[2], p[3], .5)
pts1 = [array([i[0], i[1]]) for i in seg1]
pts2 = [array([i[0], i[1]]) for i in seg2]
on1 = seg1[0]
on2 = seg2[3]
try:
off1 = calcIntersect(pts1[0], pts1[1], pts1[2], pts1[3])
off2 = calcIntersect(pts2[0], pts2[1], pts2[2], pts2[3])
except:
return (p[0],p[1],p[2],p[3])
off1 = (on1 - off1) * OFFCURVE_VECTOR_CORRECTION + off1
off2 = (on2 - off2) * OFFCURVE_VECTOR_CORRECTION + off2
return (on1,off1,off2,on2)
def cubicSegmentToQuadratic(c,sid):
segment = c[sid]
if (segment.type != "curve"):
print "Segment type not curve"
return
#pSegment,junk = getPrevAnchor(c,sid)
pSegment = c[sid-1] #assumes that a curve type will always be proceeded by another point on the same contour
points = convertToQuadratic(pSegment.points[-1],segment.points[0],
segment.points[1],segment.points[2])
return RSegment(
'qcurve', [[int(i) for i in p] for p in points[1:]], segment.smooth)
def glyphCurvesToQuadratic(g):
for c in g:
segments = []
for i in range(len(c)):
s = c[i]
if s.type == "curve":
try:
segments.append(cubicSegmentToQuadratic(c, i))
except Exception:
print g.name, i
raise
else:
segments.append(s)
replaceSegments(c, segments)
|
