From a854c55914cbb05fa9229ba401216bf07a527fdc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ju=CC=88rg=20Lehni?= <juerg@scratchdisk.com>
Date: Sat, 3 Jan 2015 01:46:22 +0100
Subject: [PATCH] Split off code from Path.Clockwise() into Curve.getEdgeSum()
---
src/path/Curve.js | 14 +++++++++++++-
src/path/Path.js | 15 +++------------
2 files changed, 16 insertions(+), 13 deletions(-)
diff --git a/src/path/Curve.js b/src/path/Curve.js
index 7ae40ef4..759d1313 100644
--- a/src/path/Curve.js
+++ b/src/path/Curve.js
@@ -1,4 +1,4 @@
-/*
+ /*
* Paper.js - The Swiss Army Knife of Vector Graphics Scripting.
* http://paperjs.org/
*
@@ -671,6 +671,18 @@ statics: {
+ 1.5 * p2y * c1x + 3.0 * p2y * c2x) / 10;
},
+ getEdgeSum: function(v) {
+ // Method derived from:
+ // http://stackoverflow.com/questions/1165647
+ // We treat the curve points and handles as the outline of a polygon of
+ // which we determine the orientation using the method of calculating
+ // the sum over the edges. This will work even with non-convex polygons,
+ // telling you whether it's mostly clockwise
+ return (v[0] - v[2]) * (v[3] + v[1])
+ + (v[2] - v[4]) * (v[5] + v[3])
+ + (v[4] - v[6]) * (v[7] + v[5]);
+ },
+
getBounds: function(v) {
var min = v.slice(0, 2), // Start with values of point1
max = min.slice(), // clone
diff --git a/src/path/Path.js b/src/path/Path.js
index b2d689cc..1bafce3a 100644
--- a/src/path/Path.js
+++ b/src/path/Path.js
@@ -2612,19 +2612,10 @@ statics: {
*/
isClockwise: function(segments) {
var sum = 0;
- // Method derived from:
- // http://stackoverflow.com/questions/1165647
- // We treat the curve points and handles as the outline of a polygon of
- // which we determine the orientation using the method of calculating
- // the sum over the edges. This will work even with non-convex polygons,
- // telling you whether it's mostly clockwise
// TODO: Check if this works correctly for all open paths.
- for (var i = 0, l = segments.length; i < l; i++) {
- var v = Curve.getValues(
- segments[i], segments[i + 1 < l ? i + 1 : 0]);
- for (var j = 2; j < 8; j += 2)
- sum += (v[j - 2] - v[j]) * (v[j + 1] + v[j - 1]);
- }
+ for (var i = 0, l = segments.length; i < l; i++)
+ sum += Curve.getEdgeSum(Curve.getValues(
+ segments[i], segments[i + 1 < l ? i + 1 : 0]));
return sum > 0;
},