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Diffstat (limited to 'misc/pylib/fontbuild/curveFitPen.pyx')
-rw-r--r-- | misc/pylib/fontbuild/curveFitPen.pyx | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/misc/pylib/fontbuild/curveFitPen.pyx b/misc/pylib/fontbuild/curveFitPen.pyx new file mode 100644 index 000000000..951ab7312 --- /dev/null +++ b/misc/pylib/fontbuild/curveFitPen.pyx @@ -0,0 +1,422 @@ +#! /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, a): + self.contourIndex += 1 + self.segmentIndex = 0 + self.startPoint = a + p = self.ssglyph.contours[self.contourIndex][0].points[0] + self.otherPen.moveTo((p.x, p.y)) + self.lastPoint = a + + def _lineTo(self, a): + 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 = a + self.lastSmooth = False + + def smoothLineTo(self, a): + self.lineTo(a) + self.lastSmooth = True + + def smoothCurveTo(self, a, b, c): + self.nextSmooth = True + self.curveTo(a, b, c) + self.nextSmooth = False + self.lastSmooth = True + + def _curveToOne(self, a, b, c): + 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 = c + 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, a): + self.contourIndex += 1 + self.segmentIndex = 0 + self.subsegments.append([]) + self.subsegmentCount = 0 + self.subsegments[self.contourIndex].append([self.subsegmentCount, 0]) + self.startContour = a + self.lastPoint = a + self.otherPen.moveTo(a) + + def _lineTo(self, a): + count = self.stepsForSegment(a,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] + (a[0] - self.lastPoint[0]) * i/float(count) + y1 = self.lastPoint[1] + (a[1] - self.lastPoint[1]) * i/float(count) + self.otherPen.lineTo((x1,y1)) + self.lastPoint = a + + def _curveToOne(self, a, b, c): + count = self.stepsForSegment(c, self.lastPoint) + if count < 2: + count = 2 + self.subsegmentCount += count + self.subsegments[self.contourIndex].append([self.subsegmentCount,count]) + x = self.renderCurve((self.lastPoint[0],a[0],b[0],c[0]),count) + y = self.renderCurve((self.lastPoint[1],a[1],b[1],c[1]),count) + assert len(x) == count + if (c[0] == self.startContour[0] and c[1] == self.startContour[1]): + count -= 1 + for i in range(count): + self.otherPen.lineTo((x[i], y[i])) + self.lastPoint = c + + 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 |