You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
459 lines
14 KiB
459 lines
14 KiB
"""
|
|
=========
|
|
PointPens
|
|
=========
|
|
|
|
Where **SegmentPens** have an intuitive approach to drawing
|
|
(if you're familiar with postscript anyway), the **PointPen**
|
|
is geared towards accessing all the data in the contours of
|
|
the glyph. A PointPen has a very simple interface, it just
|
|
steps through all the points in a call from glyph.drawPoints().
|
|
This allows the caller to provide more data for each point.
|
|
For instance, whether or not a point is smooth, and its name.
|
|
"""
|
|
|
|
import math
|
|
from typing import Any, Optional, Tuple
|
|
|
|
from fontTools.pens.basePen import AbstractPen
|
|
|
|
__all__ = [
|
|
"AbstractPointPen",
|
|
"BasePointToSegmentPen",
|
|
"PointToSegmentPen",
|
|
"SegmentToPointPen",
|
|
"GuessSmoothPointPen",
|
|
"ReverseContourPointPen",
|
|
]
|
|
|
|
|
|
class AbstractPointPen:
|
|
"""Baseclass for all PointPens."""
|
|
|
|
def beginPath(self, identifier: Optional[str] = None, **kwargs: Any) -> None:
|
|
"""Start a new sub path."""
|
|
raise NotImplementedError
|
|
|
|
def endPath(self) -> None:
|
|
"""End the current sub path."""
|
|
raise NotImplementedError
|
|
|
|
def addPoint(
|
|
self,
|
|
pt: Tuple[float, float],
|
|
segmentType: Optional[str] = None,
|
|
smooth: bool = False,
|
|
name: Optional[str] = None,
|
|
identifier: Optional[str] = None,
|
|
**kwargs: Any
|
|
) -> None:
|
|
"""Add a point to the current sub path."""
|
|
raise NotImplementedError
|
|
|
|
def addComponent(
|
|
self,
|
|
baseGlyphName: str,
|
|
transformation: Tuple[float, float, float, float, float, float],
|
|
identifier: Optional[str] = None,
|
|
**kwargs: Any
|
|
) -> None:
|
|
"""Add a sub glyph."""
|
|
raise NotImplementedError
|
|
|
|
|
|
class BasePointToSegmentPen(AbstractPointPen):
|
|
"""
|
|
Base class for retrieving the outline in a segment-oriented
|
|
way. The PointPen protocol is simple yet also a little tricky,
|
|
so when you need an outline presented as segments but you have
|
|
as points, do use this base implementation as it properly takes
|
|
care of all the edge cases.
|
|
"""
|
|
|
|
def __init__(self):
|
|
self.currentPath = None
|
|
|
|
def beginPath(self, identifier=None, **kwargs):
|
|
assert self.currentPath is None
|
|
self.currentPath = []
|
|
|
|
def _flushContour(self, segments):
|
|
"""Override this method.
|
|
|
|
It will be called for each non-empty sub path with a list
|
|
of segments: the 'segments' argument.
|
|
|
|
The segments list contains tuples of length 2:
|
|
(segmentType, points)
|
|
|
|
segmentType is one of "move", "line", "curve" or "qcurve".
|
|
"move" may only occur as the first segment, and it signifies
|
|
an OPEN path. A CLOSED path does NOT start with a "move", in
|
|
fact it will not contain a "move" at ALL.
|
|
|
|
The 'points' field in the 2-tuple is a list of point info
|
|
tuples. The list has 1 or more items, a point tuple has
|
|
four items:
|
|
(point, smooth, name, kwargs)
|
|
'point' is an (x, y) coordinate pair.
|
|
|
|
For a closed path, the initial moveTo point is defined as
|
|
the last point of the last segment.
|
|
|
|
The 'points' list of "move" and "line" segments always contains
|
|
exactly one point tuple.
|
|
"""
|
|
raise NotImplementedError
|
|
|
|
def endPath(self):
|
|
assert self.currentPath is not None
|
|
points = self.currentPath
|
|
self.currentPath = None
|
|
if not points:
|
|
return
|
|
if len(points) == 1:
|
|
# Not much more we can do than output a single move segment.
|
|
pt, segmentType, smooth, name, kwargs = points[0]
|
|
segments = [("move", [(pt, smooth, name, kwargs)])]
|
|
self._flushContour(segments)
|
|
return
|
|
segments = []
|
|
if points[0][1] == "move":
|
|
# It's an open contour, insert a "move" segment for the first
|
|
# point and remove that first point from the point list.
|
|
pt, segmentType, smooth, name, kwargs = points[0]
|
|
segments.append(("move", [(pt, smooth, name, kwargs)]))
|
|
points.pop(0)
|
|
else:
|
|
# It's a closed contour. Locate the first on-curve point, and
|
|
# rotate the point list so that it _ends_ with an on-curve
|
|
# point.
|
|
firstOnCurve = None
|
|
for i in range(len(points)):
|
|
segmentType = points[i][1]
|
|
if segmentType is not None:
|
|
firstOnCurve = i
|
|
break
|
|
if firstOnCurve is None:
|
|
# Special case for quadratics: a contour with no on-curve
|
|
# points. Add a "None" point. (See also the Pen protocol's
|
|
# qCurveTo() method and fontTools.pens.basePen.py.)
|
|
points.append((None, "qcurve", None, None, None))
|
|
else:
|
|
points = points[firstOnCurve+1:] + points[:firstOnCurve+1]
|
|
|
|
currentSegment = []
|
|
for pt, segmentType, smooth, name, kwargs in points:
|
|
currentSegment.append((pt, smooth, name, kwargs))
|
|
if segmentType is None:
|
|
continue
|
|
segments.append((segmentType, currentSegment))
|
|
currentSegment = []
|
|
|
|
self._flushContour(segments)
|
|
|
|
def addPoint(self, pt, segmentType=None, smooth=False, name=None,
|
|
identifier=None, **kwargs):
|
|
self.currentPath.append((pt, segmentType, smooth, name, kwargs))
|
|
|
|
|
|
class PointToSegmentPen(BasePointToSegmentPen):
|
|
"""
|
|
Adapter class that converts the PointPen protocol to the
|
|
(Segment)Pen protocol.
|
|
"""
|
|
|
|
def __init__(self, segmentPen, outputImpliedClosingLine=False):
|
|
BasePointToSegmentPen.__init__(self)
|
|
self.pen = segmentPen
|
|
self.outputImpliedClosingLine = outputImpliedClosingLine
|
|
|
|
def _flushContour(self, segments):
|
|
assert len(segments) >= 1
|
|
pen = self.pen
|
|
if segments[0][0] == "move":
|
|
# It's an open path.
|
|
closed = False
|
|
points = segments[0][1]
|
|
assert len(points) == 1, "illegal move segment point count: %d" % len(points)
|
|
movePt, smooth, name, kwargs = points[0]
|
|
del segments[0]
|
|
else:
|
|
# It's a closed path, do a moveTo to the last
|
|
# point of the last segment.
|
|
closed = True
|
|
segmentType, points = segments[-1]
|
|
movePt, smooth, name, kwargs = points[-1]
|
|
if movePt is None:
|
|
# quad special case: a contour with no on-curve points contains
|
|
# one "qcurve" segment that ends with a point that's None. We
|
|
# must not output a moveTo() in that case.
|
|
pass
|
|
else:
|
|
pen.moveTo(movePt)
|
|
outputImpliedClosingLine = self.outputImpliedClosingLine
|
|
nSegments = len(segments)
|
|
lastPt = movePt
|
|
for i in range(nSegments):
|
|
segmentType, points = segments[i]
|
|
points = [pt for pt, smooth, name, kwargs in points]
|
|
if segmentType == "line":
|
|
assert len(points) == 1, "illegal line segment point count: %d" % len(points)
|
|
pt = points[0]
|
|
# For closed contours, a 'lineTo' is always implied from the last oncurve
|
|
# point to the starting point, thus we can omit it when the last and
|
|
# starting point don't overlap.
|
|
# However, when the last oncurve point is a "line" segment and has same
|
|
# coordinates as the starting point of a closed contour, we need to output
|
|
# the closing 'lineTo' explicitly (regardless of the value of the
|
|
# 'outputImpliedClosingLine' option) in order to disambiguate this case from
|
|
# the implied closing 'lineTo', otherwise the duplicate point would be lost.
|
|
# See https://github.com/googlefonts/fontmake/issues/572.
|
|
if (
|
|
i + 1 != nSegments
|
|
or outputImpliedClosingLine
|
|
or not closed
|
|
or pt == lastPt
|
|
):
|
|
pen.lineTo(pt)
|
|
lastPt = pt
|
|
elif segmentType == "curve":
|
|
pen.curveTo(*points)
|
|
lastPt = points[-1]
|
|
elif segmentType == "qcurve":
|
|
pen.qCurveTo(*points)
|
|
lastPt = points[-1]
|
|
else:
|
|
assert 0, "illegal segmentType: %s" % segmentType
|
|
if closed:
|
|
pen.closePath()
|
|
else:
|
|
pen.endPath()
|
|
|
|
def addComponent(self, glyphName, transform, identifier=None, **kwargs):
|
|
del identifier # unused
|
|
self.pen.addComponent(glyphName, transform)
|
|
|
|
|
|
class SegmentToPointPen(AbstractPen):
|
|
"""
|
|
Adapter class that converts the (Segment)Pen protocol to the
|
|
PointPen protocol.
|
|
"""
|
|
|
|
def __init__(self, pointPen, guessSmooth=True):
|
|
if guessSmooth:
|
|
self.pen = GuessSmoothPointPen(pointPen)
|
|
else:
|
|
self.pen = pointPen
|
|
self.contour = None
|
|
|
|
def _flushContour(self):
|
|
pen = self.pen
|
|
pen.beginPath()
|
|
for pt, segmentType in self.contour:
|
|
pen.addPoint(pt, segmentType=segmentType)
|
|
pen.endPath()
|
|
|
|
def moveTo(self, pt):
|
|
self.contour = []
|
|
self.contour.append((pt, "move"))
|
|
|
|
def lineTo(self, pt):
|
|
assert self.contour is not None, "contour missing required initial moveTo"
|
|
self.contour.append((pt, "line"))
|
|
|
|
def curveTo(self, *pts):
|
|
assert self.contour is not None, "contour missing required initial moveTo"
|
|
for pt in pts[:-1]:
|
|
self.contour.append((pt, None))
|
|
self.contour.append((pts[-1], "curve"))
|
|
|
|
def qCurveTo(self, *pts):
|
|
if pts[-1] is None:
|
|
self.contour = []
|
|
else:
|
|
assert self.contour is not None, "contour missing required initial moveTo"
|
|
for pt in pts[:-1]:
|
|
self.contour.append((pt, None))
|
|
if pts[-1] is not None:
|
|
self.contour.append((pts[-1], "qcurve"))
|
|
|
|
def closePath(self):
|
|
assert self.contour is not None, "contour missing required initial moveTo"
|
|
if len(self.contour) > 1 and self.contour[0][0] == self.contour[-1][0]:
|
|
self.contour[0] = self.contour[-1]
|
|
del self.contour[-1]
|
|
else:
|
|
# There's an implied line at the end, replace "move" with "line"
|
|
# for the first point
|
|
pt, tp = self.contour[0]
|
|
if tp == "move":
|
|
self.contour[0] = pt, "line"
|
|
self._flushContour()
|
|
self.contour = None
|
|
|
|
def endPath(self):
|
|
assert self.contour is not None, "contour missing required initial moveTo"
|
|
self._flushContour()
|
|
self.contour = None
|
|
|
|
def addComponent(self, glyphName, transform):
|
|
assert self.contour is None
|
|
self.pen.addComponent(glyphName, transform)
|
|
|
|
|
|
class GuessSmoothPointPen(AbstractPointPen):
|
|
"""
|
|
Filtering PointPen that tries to determine whether an on-curve point
|
|
should be "smooth", ie. that it's a "tangent" point or a "curve" point.
|
|
"""
|
|
|
|
def __init__(self, outPen):
|
|
self._outPen = outPen
|
|
self._points = None
|
|
|
|
def _flushContour(self):
|
|
points = self._points
|
|
nPoints = len(points)
|
|
if not nPoints:
|
|
return
|
|
if points[0][1] == "move":
|
|
# Open path.
|
|
indices = range(1, nPoints - 1)
|
|
elif nPoints > 1:
|
|
# Closed path. To avoid having to mod the contour index, we
|
|
# simply abuse Python's negative index feature, and start at -1
|
|
indices = range(-1, nPoints - 1)
|
|
else:
|
|
# closed path containing 1 point (!), ignore.
|
|
indices = []
|
|
for i in indices:
|
|
pt, segmentType, dummy, name, kwargs = points[i]
|
|
if segmentType is None:
|
|
continue
|
|
prev = i - 1
|
|
next = i + 1
|
|
if points[prev][1] is not None and points[next][1] is not None:
|
|
continue
|
|
# At least one of our neighbors is an off-curve point
|
|
pt = points[i][0]
|
|
prevPt = points[prev][0]
|
|
nextPt = points[next][0]
|
|
if pt != prevPt and pt != nextPt:
|
|
dx1, dy1 = pt[0] - prevPt[0], pt[1] - prevPt[1]
|
|
dx2, dy2 = nextPt[0] - pt[0], nextPt[1] - pt[1]
|
|
a1 = math.atan2(dx1, dy1)
|
|
a2 = math.atan2(dx2, dy2)
|
|
if abs(a1 - a2) < 0.05:
|
|
points[i] = pt, segmentType, True, name, kwargs
|
|
|
|
for pt, segmentType, smooth, name, kwargs in points:
|
|
self._outPen.addPoint(pt, segmentType, smooth, name, **kwargs)
|
|
|
|
def beginPath(self, identifier=None, **kwargs):
|
|
assert self._points is None
|
|
self._points = []
|
|
if identifier is not None:
|
|
kwargs["identifier"] = identifier
|
|
self._outPen.beginPath(**kwargs)
|
|
|
|
def endPath(self):
|
|
self._flushContour()
|
|
self._outPen.endPath()
|
|
self._points = None
|
|
|
|
def addPoint(self, pt, segmentType=None, smooth=False, name=None,
|
|
identifier=None, **kwargs):
|
|
if identifier is not None:
|
|
kwargs["identifier"] = identifier
|
|
self._points.append((pt, segmentType, False, name, kwargs))
|
|
|
|
def addComponent(self, glyphName, transformation, identifier=None, **kwargs):
|
|
assert self._points is None
|
|
if identifier is not None:
|
|
kwargs["identifier"] = identifier
|
|
self._outPen.addComponent(glyphName, transformation, **kwargs)
|
|
|
|
|
|
class ReverseContourPointPen(AbstractPointPen):
|
|
"""
|
|
This is a PointPen that passes outline data to another PointPen, but
|
|
reversing the winding direction of all contours. Components are simply
|
|
passed through unchanged.
|
|
|
|
Closed contours are reversed in such a way that the first point remains
|
|
the first point.
|
|
"""
|
|
|
|
def __init__(self, outputPointPen):
|
|
self.pen = outputPointPen
|
|
# a place to store the points for the current sub path
|
|
self.currentContour = None
|
|
|
|
def _flushContour(self):
|
|
pen = self.pen
|
|
contour = self.currentContour
|
|
if not contour:
|
|
pen.beginPath(identifier=self.currentContourIdentifier)
|
|
pen.endPath()
|
|
return
|
|
|
|
closed = contour[0][1] != "move"
|
|
if not closed:
|
|
lastSegmentType = "move"
|
|
else:
|
|
# Remove the first point and insert it at the end. When
|
|
# the list of points gets reversed, this point will then
|
|
# again be at the start. In other words, the following
|
|
# will hold:
|
|
# for N in range(len(originalContour)):
|
|
# originalContour[N] == reversedContour[-N]
|
|
contour.append(contour.pop(0))
|
|
# Find the first on-curve point.
|
|
firstOnCurve = None
|
|
for i in range(len(contour)):
|
|
if contour[i][1] is not None:
|
|
firstOnCurve = i
|
|
break
|
|
if firstOnCurve is None:
|
|
# There are no on-curve points, be basically have to
|
|
# do nothing but contour.reverse().
|
|
lastSegmentType = None
|
|
else:
|
|
lastSegmentType = contour[firstOnCurve][1]
|
|
|
|
contour.reverse()
|
|
if not closed:
|
|
# Open paths must start with a move, so we simply dump
|
|
# all off-curve points leading up to the first on-curve.
|
|
while contour[0][1] is None:
|
|
contour.pop(0)
|
|
pen.beginPath(identifier=self.currentContourIdentifier)
|
|
for pt, nextSegmentType, smooth, name, kwargs in contour:
|
|
if nextSegmentType is not None:
|
|
segmentType = lastSegmentType
|
|
lastSegmentType = nextSegmentType
|
|
else:
|
|
segmentType = None
|
|
pen.addPoint(pt, segmentType=segmentType, smooth=smooth, name=name, **kwargs)
|
|
pen.endPath()
|
|
|
|
def beginPath(self, identifier=None, **kwargs):
|
|
assert self.currentContour is None
|
|
self.currentContour = []
|
|
self.currentContourIdentifier = identifier
|
|
self.onCurve = []
|
|
|
|
def endPath(self):
|
|
assert self.currentContour is not None
|
|
self._flushContour()
|
|
self.currentContour = None
|
|
|
|
def addPoint(self, pt, segmentType=None, smooth=False, name=None, **kwargs):
|
|
self.currentContour.append((pt, segmentType, smooth, name, kwargs))
|
|
|
|
def addComponent(self, glyphName, transform, identifier=None, **kwargs):
|
|
assert self.currentContour is None
|
|
self.pen.addComponent(glyphName, transform, identifier=identifier, **kwargs)
|