"""Calculate the area of a glyph."""

from __future__ import print_function, division, absolute_import
from fontTools.misc.py23 import *
from fontTools.pens.basePen import BasePen


def interpolate(p0, p1, t):
	return (p0[0] * (1 - t) + p1[0] * t, p0[1] * (1 - t) + p1[1] * t)


def polygon_area(p0, p1):
	return -(p1[0] - p0[0]) * (p1[1] + p0[1]) * 0.5


def quadratic_curve_area(p0, p1, p2):
	new_p2 = interpolate(p2, p1, 2.0 / 3)
	new_p1 = interpolate(p0, p1, 2.0 / 3)
	return cubic_curve_area(p0, new_p1, new_p2, p2)


def cubic_curve_area(p0, p1, p2, p3):
	x0, y0 = p0[0], p0[1]
	x1, y1 = p1[0] - x0, p1[1] - y0
	x2, y2 = p2[0] - x0, p2[1] - y0
	x3, y3 = p3[0] - x0, p3[1] - y0
	return -(
		x1 * (   -   y2 -   y3) +
		x2 * (y1        - 2*y3) +
		x3 * (y1 + 2*y2       )
	) * 0.15


class AreaPen(BasePen):

	def __init__(self, glyphset):
		BasePen.__init__(self, glyphset)
		self.value = 0

	def _moveTo(self, p0):
		pass

	def _lineTo(self, p1):
		p0 = self._getCurrentPoint()
		self.value += polygon_area(p0, p1)

	def _curveToOne(self, p1, p2, p3):
		p0 = self._getCurrentPoint()
		self.value += cubic_curve_area(p0, p1, p2, p3)
		self.value += polygon_area(p0, p3)

	def _qCurveToOne(self, p1, p2):
		p0 = self._getCurrentPoint()
		self.value += quadratic_curve_area(p0, p1, p2)
		self.value += polygon_area(p0, p2)

@@ -834,16 +834,21 @@
 glyphset
+=None
 ):%0A%09%09Bas
@@ -925,12 +925,30 @@
 :%0A%09%09
-pass
+self.__startPoint = p0
 %0A%0A%09d
@@ -1338,12 +1338,132 @@
 rea(p0, p2)%0A
+%0A%09def _closePath(self):%0A%09%09p0 = self._getCurrentPoint()%0A%09%09if p0 != self.__startPoint:%0A%09%09%09self._lineTo(self.__startPoint)%0A

make sure the first and last points of contour overlap