This repository has been archived on 2025-10-02. You can view files and clone it, but you cannot make any changes to it's state, such as pushing and creating new issues, pull requests or comments.
inter-font/misc/pylib/fontbuild/curveFitPen.py

422 lines
15 KiB
Python

#! /opt/local/bin/pythonw2.7
#
# 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.
__all__ = ["SubsegmentPen","SubsegmentsToCurvesPen", "segmentGlyph", "fitGlyph"]
from fontTools.pens.basePen import BasePen
import numpy as np
from numpy import array as v
from numpy.linalg import norm
from robofab.pens.adapterPens import GuessSmoothPointPen
from robofab.pens.pointPen import BasePointToSegmentPen
class SubsegmentsToCurvesPointPen(BasePointToSegmentPen):
def __init__(self, glyph, subsegmentGlyph, subsegments):
BasePointToSegmentPen.__init__(self)
self.glyph = glyph
self.subPen = SubsegmentsToCurvesPen(None, glyph.getPen(), subsegmentGlyph, subsegments)
def setMatchTangents(self, b):
self.subPen.matchTangents = b
def _flushContour(self, segments):
#
# adapted from robofab.pens.adapterPens.rfUFOPointPen
#
assert len(segments) >= 1
# if we only have one point and it has a name, we must have an anchor
first = segments[0]
segmentType, points = first
pt, smooth, name, kwargs = points[0]
if len(segments) == 1 and name != None:
self.glyph.appendAnchor(name, pt)
return
else:
segmentType, points = segments[-1]
movePt, smooth, name, kwargs = points[-1]
if smooth:
# last point is smooth, set pen to start smooth
self.subPen.setLastSmooth(True)
if segmentType == 'line':
del segments[-1]
self.subPen.moveTo(movePt)
# do the rest of the segments
for segmentType, points in segments:
isSmooth = True in [smooth for pt, smooth, name, kwargs in points]
pp = [pt for pt, smooth, name, kwargs in points]
if segmentType == "line":
assert len(pp) == 1
if isSmooth:
self.subPen.smoothLineTo(pp[0])
else:
self.subPen.lineTo(pp[0])
elif segmentType == "curve":
assert len(pp) == 3
if isSmooth:
self.subPen.smoothCurveTo(*pp)
else:
self.subPen.curveTo(*pp)
elif segmentType == "qcurve":
assert 0, "qcurve not supported"
else:
assert 0, "illegal segmentType: %s" % segmentType
self.subPen.closePath()
def addComponent(self, glyphName, transform):
self.subPen.addComponent(glyphName, transform)
class SubsegmentsToCurvesPen(BasePen):
def __init__(self, glyphSet, otherPen, subsegmentGlyph, subsegments):
BasePen.__init__(self, None)
self.otherPen = otherPen
self.ssglyph = subsegmentGlyph
self.subsegments = subsegments
self.contourIndex = -1
self.segmentIndex = -1
self.lastPoint = (0,0)
self.lastSmooth = False
self.nextSmooth = False
def setLastSmooth(self, b):
self.lastSmooth = b
def _moveTo(self, (x, y)):
self.contourIndex += 1
self.segmentIndex = 0
self.startPoint = (x,y)
p = self.ssglyph.contours[self.contourIndex][0].points[0]
self.otherPen.moveTo((p.x, p.y))
self.lastPoint = (x,y)
def _lineTo(self, (x, y)):
self.segmentIndex += 1
index = self.subsegments[self.contourIndex][self.segmentIndex][0]
p = self.ssglyph.contours[self.contourIndex][index].points[0]
self.otherPen.lineTo((p.x, p.y))
self.lastPoint = (x,y)
self.lastSmooth = False
def smoothLineTo(self, (x, y)):
self.lineTo((x,y))
self.lastSmooth = True
def smoothCurveTo(self, (x1, y1), (x2, y2), (x3, y3)):
self.nextSmooth = True
self.curveTo((x1, y1), (x2, y2), (x3, y3))
self.nextSmooth = False
self.lastSmooth = True
def _curveToOne(self, (x1, y1), (x2, y2), (x3, y3)):
self.segmentIndex += 1
c = self.ssglyph.contours[self.contourIndex]
n = len(c)
startIndex = (self.subsegments[self.contourIndex][self.segmentIndex-1][0])
segmentCount = (self.subsegments[self.contourIndex][self.segmentIndex][1])
endIndex = (startIndex + segmentCount + 1) % (n)
indices = [(startIndex + i) % (n) for i in range(segmentCount + 1)]
points = np.array([(c[i].points[0].x, c[i].points[0].y) for i in indices])
prevPoint = (c[(startIndex - 1)].points[0].x, c[(startIndex - 1)].points[0].y)
nextPoint = (c[(endIndex) % n].points[0].x, c[(endIndex) % n].points[0].y)
prevTangent = prevPoint - points[0]
nextTangent = nextPoint - points[-1]
tangent1 = points[1] - points[0]
tangent3 = points[-2] - points[-1]
prevTangent /= np.linalg.norm(prevTangent)
nextTangent /= np.linalg.norm(nextTangent)
tangent1 /= np.linalg.norm(tangent1)
tangent3 /= np.linalg.norm(tangent3)
tangent1, junk = self.smoothTangents(tangent1, prevTangent, self.lastSmooth)
tangent3, junk = self.smoothTangents(tangent3, nextTangent, self.nextSmooth)
if self.matchTangents == True:
cp = fitBezier(points, tangent1, tangent3)
cp[1] = norm(cp[1] - cp[0]) * tangent1 / norm(tangent1) + cp[0]
cp[2] = norm(cp[2] - cp[3]) * tangent3 / norm(tangent3) + cp[3]
else:
cp = fitBezier(points)
# if self.ssglyph.name == 'r':
# print "-----------"
# print self.lastSmooth, self.nextSmooth
# print "%i %i : %i %i \n %i %i : %i %i \n %i %i : %i %i"%(x1,y1, cp[1,0], cp[1,1], x2,y2, cp[2,0], cp[2,1], x3,y3, cp[3,0], cp[3,1])
self.otherPen.curveTo((cp[1,0], cp[1,1]), (cp[2,0], cp[2,1]), (cp[3,0], cp[3,1]))
self.lastPoint = (x3, y3)
self.lastSmooth = False
def smoothTangents(self,t1,t2,forceSmooth = False):
if forceSmooth or (abs(t1.dot(t2)) > .95 and norm(t1-t2) > 1):
# print t1,t2,
t1 = (t1 - t2) / 2
t2 = -t1
# print t1,t2
return t1 / norm(t1), t2 / norm(t2)
def _closePath(self):
self.otherPen.closePath()
def _endPath(self):
self.otherPen.endPath()
def addComponent(self, glyphName, transformation):
self.otherPen.addComponent(glyphName, transformation)
class SubsegmentPointPen(BasePointToSegmentPen):
def __init__(self, glyph, resolution):
BasePointToSegmentPen.__init__(self)
self.glyph = glyph
self.resolution = resolution
self.subPen = SubsegmentPen(None, glyph.getPen())
def getSubsegments(self):
return self.subPen.subsegments[:]
def _flushContour(self, segments):
#
# adapted from robofab.pens.adapterPens.rfUFOPointPen
#
assert len(segments) >= 1
# if we only have one point and it has a name, we must have an anchor
first = segments[0]
segmentType, points = first
pt, smooth, name, kwargs = points[0]
if len(segments) == 1 and name != None:
self.glyph.appendAnchor(name, pt)
return
else:
segmentType, points = segments[-1]
movePt, smooth, name, kwargs = points[-1]
if segmentType == 'line':
del segments[-1]
self.subPen.moveTo(movePt)
# do the rest of the segments
for segmentType, points in segments:
points = [pt for pt, smooth, name, kwargs in points]
if segmentType == "line":
assert len(points) == 1
self.subPen.lineTo(points[0])
elif segmentType == "curve":
assert len(points) == 3
self.subPen.curveTo(*points)
elif segmentType == "qcurve":
assert 0, "qcurve not supported"
else:
assert 0, "illegal segmentType: %s" % segmentType
self.subPen.closePath()
def addComponent(self, glyphName, transform):
self.subPen.addComponent(glyphName, transform)
class SubsegmentPen(BasePen):
def __init__(self, glyphSet, otherPen, resolution=25):
BasePen.__init__(self,glyphSet)
self.resolution = resolution
self.otherPen = otherPen
self.subsegments = []
self.startContour = (0,0)
self.contourIndex = -1
def _moveTo(self, (x, y)):
self.contourIndex += 1
self.segmentIndex = 0
self.subsegments.append([])
self.subsegmentCount = 0
self.subsegments[self.contourIndex].append([self.subsegmentCount, 0])
self.startContour = (x,y)
self.lastPoint = (x,y)
self.otherPen.moveTo((x,y))
def _lineTo(self, (x, y)):
count = self.stepsForSegment((x,y),self.lastPoint)
if count < 1:
count = 1
self.subsegmentCount += count
self.subsegments[self.contourIndex].append([self.subsegmentCount, count])
for i in range(1,count+1):
x1 = self.lastPoint[0] + (x - self.lastPoint[0]) * i/float(count)
y1 = self.lastPoint[1] + (y - self.lastPoint[1]) * i/float(count)
self.otherPen.lineTo((x1,y1))
self.lastPoint = (x,y)
def _curveToOne(self, (x1, y1), (x2, y2), (x3, y3)):
count = self.stepsForSegment((x3,y3),self.lastPoint)
if count < 2:
count = 2
self.subsegmentCount += count
self.subsegments[self.contourIndex].append([self.subsegmentCount,count])
x = self.renderCurve((self.lastPoint[0],x1,x2,x3),count)
y = self.renderCurve((self.lastPoint[1],y1,y2,y3),count)
assert len(x) == count
if (x3 == self.startContour[0] and y3 == self.startContour[1]):
count -= 1
for i in range(count):
self.otherPen.lineTo((x[i],y[i]))
self.lastPoint = (x3,y3)
def _closePath(self):
if not (self.lastPoint[0] == self.startContour[0] and self.lastPoint[1] == self.startContour[1]):
self._lineTo(self.startContour)
# round values used by otherPen (a RoboFab SegmentToPointPen) to decide
# whether to delete duplicate points at start and end of contour
#TODO(jamesgk) figure out why we have to do this hack, then remove it
c = self.otherPen.contour
for i in [0, -1]:
c[i] = [[round(n, 5) for n in c[i][0]]] + list(c[i][1:])
self.otherPen.closePath()
def _endPath(self):
self.otherPen.endPath()
def addComponent(self, glyphName, transformation):
self.otherPen.addComponent(glyphName, transformation)
def stepsForSegment(self, p1, p2):
dist = np.linalg.norm(v(p1) - v(p2))
out = int(dist / self.resolution)
return out
def renderCurve(self,p,count):
curvePoints = []
t = 1.0 / float(count)
temp = t * t
f = p[0]
fd = 3 * (p[1] - p[0]) * t
fdd_per_2 = 3 * (p[0] - 2 * p[1] + p[2]) * temp
fddd_per_2 = 3 * (3 * (p[1] - p[2]) + p[3] - p[0]) * temp * t
fddd = fddd_per_2 + fddd_per_2
fdd = fdd_per_2 + fdd_per_2
fddd_per_6 = fddd_per_2 * (1.0 / 3)
for i in range(count):
f = f + fd + fdd_per_2 + fddd_per_6
fd = fd + fdd + fddd_per_2
fdd = fdd + fddd
fdd_per_2 = fdd_per_2 + fddd_per_2
curvePoints.append(f)
return curvePoints
def fitBezierSimple(pts):
T = [np.linalg.norm(pts[i]-pts[i-1]) for i in range(1,len(pts))]
tsum = np.sum(T)
T = [0] + T
T = [np.sum(T[0:i+1])/tsum for i in range(len(pts))]
T = [[t**3, t**2, t, 1] for t in T]
T = np.array(T)
M = np.array([[-1, 3, -3, 1],
[ 3, -6, 3, 0],
[-3, 3, 0, 0],
[ 1, 0, 0, 0]])
T = T.dot(M)
T = np.concatenate((T, np.array([[100,0,0,0], [0,0,0,100]])))
# pts = np.vstack((pts, pts[0] * 100, pts[-1] * 100))
C = np.linalg.lstsq(T, pts)
return C[0]
def subdivideLineSegment(pts):
out = [pts[0]]
for i in range(1, len(pts)):
out.append(pts[i-1] + (pts[i] - pts[i-1]) * .5)
out.append(pts[i])
return np.array(out)
def fitBezier(pts,tangent0=None,tangent3=None):
if len(pts < 4):
pts = subdivideLineSegment(pts)
T = [np.linalg.norm(pts[i]-pts[i-1]) for i in range(1,len(pts))]
tsum = np.sum(T)
T = [0] + T
T = [np.sum(T[0:i+1])/tsum for i in range(len(pts))]
T = [[t**3, t**2, t, 1] for t in T]
T = np.array(T)
M = np.array([[-1, 3, -3, 1],
[ 3, -6, 3, 0],
[-3, 3, 0, 0],
[ 1, 0, 0, 0]])
T = T.dot(M)
n = len(pts)
pout = pts.copy()
pout[:,0] -= (T[:,0] * pts[0,0]) + (T[:,3] * pts[-1,0])
pout[:,1] -= (T[:,0] * pts[0,1]) + (T[:,3] * pts[-1,1])
TT = np.zeros((n*2,4))
for i in range(n):
for j in range(2):
TT[i*2,j*2] = T[i,j+1]
TT[i*2+1,j*2+1] = T[i,j+1]
pout = pout.reshape((n*2,1),order="C")
if tangent0 is not None and tangent3 is not None:
tangentConstraintsT = np.array([
[tangent0[1], -tangent0[0], 0, 0],
[0, 0, tangent3[1], -tangent3[0]]
])
tangentConstraintsP = np.array([
[pts[0][1] * -tangent0[0] + pts[0][0] * tangent0[1]],
[pts[-1][1] * -tangent3[0] + pts[-1][0] * tangent3[1]]
])
TT = np.concatenate((TT, tangentConstraintsT * 1000))
pout = np.concatenate((pout, tangentConstraintsP * 1000))
C = np.linalg.lstsq(TT,pout)[0].reshape((2,2))
return np.array([pts[0], C[0], C[1], pts[-1]])
def segmentGlyph(glyph,resolution=50):
g1 = glyph.copy()
g1.clear()
dp = SubsegmentPointPen(g1, resolution)
glyph.drawPoints(dp)
return g1, dp.getSubsegments()
def fitGlyph(glyph, subsegmentGlyph, subsegmentIndices, matchTangents=True):
outGlyph = glyph.copy()
outGlyph.clear()
fitPen = SubsegmentsToCurvesPointPen(outGlyph, subsegmentGlyph, subsegmentIndices)
fitPen.setMatchTangents(matchTangents)
# smoothPen = GuessSmoothPointPen(fitPen)
glyph.drawPoints(fitPen)
outGlyph.width = subsegmentGlyph.width
return outGlyph
if __name__ == '__main__':
p = SubsegmentPen(None, None)
pts = np.array([
[0,0],
[.5,.5],
[.5,.5],
[1,1]
])
print np.array(p.renderCurve(pts,10)) * 10