1 files changed, 125 insertions, 0 deletions
diff --git a/misc/pylib/robofab/pens/reverseContourPointPen.py b/misc/pylib/robofab/pens/reverseContourPointPen.py
new file mode 100755
index 000000000..8ce001b4d
--- /dev/null
+++ b/misc/pylib/robofab/pens/reverseContourPointPen.py
@@ -0,0 +1,125 @@
+"""PointPen for reversing the winding direction of contours."""
+
+
+__all__ = ["ReverseContourPointPen"]
+
+
+from robofab.pens.pointPen import AbstractPointPen
+
+
+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
+		self.currentContour = None  # a place to store the points for the current sub path
+
+	def _flushContour(self):
+		pen = self.pen
+		contour = self.currentContour
+		if not contour:
+			pen.beginPath()
+			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()
+		for pt, nextSegmentType, smooth, name in contour:
+			if nextSegmentType is not None:
+				segmentType = lastSegmentType
+				lastSegmentType = nextSegmentType
+			else:
+				segmentType = None
+			pen.addPoint(pt, segmentType=segmentType, smooth=smooth, name=name)
+		pen.endPath()
+
+	def beginPath(self):
+		assert self.currentContour is None
+		self.currentContour = []
+		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))
+
+	def addComponent(self, glyphName, transform):
+		assert self.currentContour is None
+		self.pen.addComponent(glyphName, transform)
+
+
+if __name__ == "__main__":
+	from robofab.pens.pointPen import PrintingPointPen
+	pP = PrintingPointPen()
+	rP = ReverseContourPointPen(pP)
+
+	rP.beginPath()
+	rP.addPoint((339, -8), "curve")
+	rP.addPoint((502, -8))
+	rP.addPoint((635, 65))
+	rP.addPoint((635, 305), "curve")
+	rP.addPoint((635, 545))
+	rP.addPoint((504, 623))
+	rP.addPoint((340, 623), "curve")
+	rP.addPoint((177, 623))
+	rP.addPoint((43, 545))
+	rP.addPoint((43, 305), "curve")
+	rP.addPoint((43, 65))
+	rP.addPoint((176, -8))
+	rP.endPath()
+
+	rP.beginPath()
+	rP.addPoint((100, 100), "move", smooth=False, name='a')
+	rP.addPoint((150, 150))
+	rP.addPoint((200, 200))
+	rP.addPoint((250, 250), "curve", smooth=True, name='b')
+	rP.addPoint((300, 300), "line", smooth=False, name='c')
+	rP.addPoint((350, 350))
+	rP.addPoint((400, 400))
+	rP.addPoint((450, 450))
+	rP.addPoint((500, 500), "curve", smooth=True, name='d')
+	rP.addPoint((550, 550))
+	rP.addPoint((600, 600))
+	rP.addPoint((650, 650))
+	rP.addPoint((700, 700))
+	rP.addPoint((750, 750), "qcurve", smooth=False, name='e')
+	rP.endPath()