From 41aca10112a17513e04745182d65bc10520be878 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=BCrg=20Lehni?= <juerg@scratchdisk.com>
Date: Wed, 3 Feb 2016 12:54:54 +0100
Subject: [PATCH] Clean-up changes from #939

---
 src/path/PathItem.Boolean.js | 26 ++++++++++++++------------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/path/PathItem.Boolean.js b/src/path/PathItem.Boolean.js
index cbf6ae17..c1e40c94 100644
--- a/src/path/PathItem.Boolean.js
+++ b/src/path/PathItem.Boolean.js
@@ -314,6 +314,7 @@ PathItem.inject(new function() {
             py = point.y,
             windLeft = 0,
             windRight = 0,
+            isOnCurve = false,
             length = curves.length,
             roots = [],
             abs = Math.abs;
@@ -349,17 +350,15 @@ PathItem.inject(new function() {
             var xBefore = px - epsilon,
                 xAfter = px + epsilon,
                 prevWinding,
-                prevXEnd,
-                isOnCurve;
+                prevXEnd;
             for (var i = 0; i < length; i++) {
                 var curve = curves[i],
                     winding = curve.winding,
                     values = curve.values,
                     yStart = values[1],
                     yEnd = values[7];
-                // The first curve of a loop holds the last curve with
-                // non-zero winding.
-                // Retrieve and use it here (See _getMonoCurve()).
+                // The first curve of a loop holds the last curve with non-zero
+                // winding. Retrieve and use it here (See _getMonoCurve()).
                 if (curve.last) {
                     // Get the end x coordinate and winding of the last
                     // non-horizontal curve, which will be the previous
@@ -374,19 +373,19 @@ PathItem.inject(new function() {
                 // Horizontal curves with winding == 0 will be completely
                 // ignored.
                 if (winding && (py >= yStart && py <= yEnd
-                    || py >= yEnd && py <= yStart)) {
+                        || py >= yEnd && py <= yStart)) {
                     // Calculate the x value for the ray's intersection.
                     var x = py === yStart ? values[0]
                         :   py === yEnd   ? values[6]
                         : Curve.solveCubic(values, 1, py, roots, 0, 1) === 1
-                        ? Curve.getPoint(values, roots[0]).x
-                        : null;
+                            ? Curve.getPoint(values, roots[0]).x
+                            : null;
                     if (x != null) {
                         // If the point is between the curve's start point and
                         // the previous curve's end point, it must be on a
-                        // horizontal curve inbetween.
+                        // horizontal curve in between.
                         var isOnHorizontal =
-                            (py === yStart && (px - x) * (px - prevXEnd) < 0);
+                                py === yStart && (px - x) * (px - prevXEnd) < 0;
                         // Test if the point is on a y-monotonic curve
                         if ((x >= xBefore && x <= xAfter) || isOnHorizontal)
                             isOnCurve = true;
@@ -396,7 +395,7 @@ PathItem.inject(new function() {
                         // - or the crossing is at the start of the curve and
                         //   the winding did not change between curves
                         if (py != yEnd
-                            && (py != yStart || winding === prevWinding)) {
+                                && (py != yStart || winding === prevWinding)) {
                             if (x < xBefore) {
                                 windLeft += winding;
                             } else if (x > xAfter) {
@@ -411,7 +410,10 @@ PathItem.inject(new function() {
                 }
             }
         }
-        // If the point was on a monocurve, ensure that the winding is odd.
+        // If the point is on a monotonic curve, ensure that the winding is odd
+        // by applying bit-wise or `| 1` to the bigger absolute winding number:
+        // If winding is an even number and the point is on a curve, this will
+        // add up to the next uneven number, otherwise it remains the same.
         return Math.max(abs(windLeft), abs(windRight)) | (isOnCurve ? 1 : 0 );
     }