Fix PointInsidePen

https://github.com/behdad/fonttools/issues/621

Lib/fontTools/misc/bezierTools.py

@@ -18,8 +18,8 @@ __all__ = [
 
 from fontTools.misc.arrayTools import calcBounds
 
-epsilonDigits = 12
+epsilonDigits = 6
-epsilon = 1e-12
+epsilon = 1e-10
 
 
 def calcQuadraticBounds(pt1, pt2, pt3):

Lib/fontTools/pens/pointInsidePen.py

@@ -11,12 +11,6 @@ from fontTools.misc.bezierTools import solveQuadratic, solveCubic
 __all__ = ["PointInsidePen"]
 
 
-# working around floating point errors
-EPSILON = 1e-10
-ONE_PLUS_EPSILON = 1 + EPSILON
-ZERO_MINUS_EPSILON = 0 - EPSILON
-
-
 class PointInsidePen(BasePen):
 
 	"""This pen implements "point inside" testing: to test whether
@@ -123,7 +117,7 @@ class PointInsidePen(BasePen):
 		by = (y3 - y2) * 3.0 - cy
 		ay = y4 - dy - cy - by
 		solutions = sorted(solveCubic(ay, by, cy, dy - y))
-		solutions = [t for t in solutions if ZERO_MINUS_EPSILON <= t <= ONE_PLUS_EPSILON]
+		solutions = [t for t in solutions if -0. <= t <= 1.]
 		if not solutions:
 			return
 
@@ -142,29 +136,30 @@ class PointInsidePen(BasePen):
 			t3 = t2 * t
 
 			direction = 3*ay*t2 + 2*by*t + cy
+			incomingGoingUp = outgoingGoingUp = direction > 0.0
 			if direction == 0.0:
 				direction = 6*ay*t + 2*by
+				outgoingGoingUp = direction > 0.0
+				incomingGoingUp = not outgoingGoingUp
 				if direction == 0.0:
 					direction = ay
-			goingUp = direction > 0.0
+					incomingGoingUp = outgoingGoingUp = direction > 0.0
 
 			xt = ax*t3 + bx*t2 + cx*t + dx
 			if xt < x:
-				above = goingUp
 				continue
 
-			if t == 0.0:
+			if t in (0.0, -0.0):
-				if not goingUp:
+				if not outgoingGoingUp:
-					self._addIntersection(goingUp)
+					self._addIntersection(outgoingGoingUp)
 			elif t == 1.0:
-				if not above:
+				if incomingGoingUp:
-					self._addIntersection(goingUp)
+					self._addIntersection(incomingGoingUp)
 			else:
-				if above != goingUp:
+				if incomingGoingUp == outgoingGoingUp:
-					self._addIntersection(goingUp)
+					self._addIntersection(outgoingGoingUp)
 				#else:
-				#   we're not really intersecting, merely touching the 'top'
+				#   we're not really intersecting, merely touching
-			above = goingUp
 
 	def _qCurveToOne_unfinished(self, bcp, point):
 		# XXX need to finish this, for now doing it through a cubic

Lib/fontTools/pens/pointInsidePen_test.py

@@ -71,34 +71,6 @@ class PointInsidePenTest(unittest.TestCase):
             "**     ***",
             self.render(draw_qCurves, even_odd=False))
 
-    def test_contour_integers(self):
-        def draw_contour(pen):
-            pen.moveTo( (728, 697) )
-            pen.curveTo( (723, 698) , (718, 699) , (713, 699) )
-            pen.lineTo( (504, 699) )
-            pen.curveTo( (487, 719) , (508, 783) , (556, 783) )
-            pen.lineTo( (718, 783) )
-            pen.curveTo( (739, 783) , (749, 712) , (728, 697) )
-            pen.closePath()
-
-        piPen = PointInsidePen(None, (416, 783)) # this point is outside
-        draw_contour(piPen)
-        self.assertEqual(piPen.getResult(), False)
-
-    def test_contour_decimals(self):
-        def draw_contour(pen):
-            pen.moveTo( (727.546875, 697.0) )
-            pen.curveTo( (722.953125, 697.953125), (718.109375, 698.515625), (712.9375, 698.515625) )
-            pen.lineTo( (504.375, 698.515625) )
-            pen.curveTo( (487.328125, 719.359375), (507.84375, 783.140625), (555.796875, 783.140625) )
-            pen.lineTo( (717.96875, 783.140625) )
-            pen.curveTo( (738.890625, 783.140625), (748.796875, 711.5), (727.546875, 697.0) )
-            pen.closePath()
-
-        piPen = PointInsidePen(None, (416.625, 783.140625)) # this point is outside
-        draw_contour(piPen)
-        self.assertEqual(piPen.getResult(), False)
-
     @staticmethod
     def render(draw_function, even_odd):
         result = BytesIO()
@@ -113,6 +85,56 @@ class PointInsidePenTest(unittest.TestCase):
         return tounicode(result.getvalue())
 
 
+    def test_contour_diamond(self):
+        def draw_contour(pen):
+            pen.moveTo( (0, 100) )
+            pen.lineTo( (100, 0) )
+            pen.lineTo( (0, -100) )
+            pen.lineTo( (-100, 0) )
+            pen.closePath()
+
+        piPen = PointInsidePen(None, (-200, 0)) # this point is outside
+        draw_contour(piPen)
+        self.assertEqual(piPen.intersectionCount, 0)
+
+        piPen = PointInsidePen(None, (-200, 100)) # this point is outside
+        draw_contour(piPen)
+        self.assertEqual(piPen.intersectionCount, 0)
+
+        piPen = PointInsidePen(None, (-200, -100)) # this point is outside
+        draw_contour(piPen)
+        self.assertEqual(piPen.intersectionCount, 0)
+
+        piPen = PointInsidePen(None, (-200, 50)) # this point is outside
+        draw_contour(piPen)
+        self.assertEqual(piPen.intersectionCount, 0)
+
+    def test_contour_integers(self):
+        def draw_contour(pen):
+            pen.moveTo( (728, 697) )
+            pen.lineTo( (504, 699) )
+            pen.curveTo( (487, 719) , (508, 783) , (556, 783) )
+            pen.lineTo( (718, 783) )
+            pen.curveTo( (739, 783) , (749, 712) , (728, 697) )
+            pen.closePath()
+
+        piPen = PointInsidePen(None, (416, 783)) # this point is outside
+        draw_contour(piPen)
+        self.assertEqual(piPen.intersectionCount, 0)
+
+    def test_contour_decimals(self):
+        def draw_contour(pen):
+            pen.moveTo( (727.546875, 697.0) )
+            pen.lineTo( (504.375, 698.515625) )
+            pen.curveTo( (487.328125, 719.359375), (507.84375, 783.140625), (555.796875, 783.140625) )
+            pen.lineTo( (717.96875, 783.140625) )
+            pen.curveTo( (738.890625, 783.140625), (748.796875, 711.5), (727.546875, 697.0) )
+            pen.closePath()
+
+        piPen = PointInsidePen(None, (416.625, 783.140625)) # this point is outside
+        draw_contour(piPen)
+        self.assertEqual(piPen.intersectionCount, 0)
+
 if __name__ == "__main__":
     unittest.main()