From c5ddbf19da04d55a6f12fa435bc72b0dbd640331 Mon Sep 17 00:00:00 2001
From: hkrish <hari.exeption@gmail.com>
Date: Sun, 26 Jan 2014 05:38:09 +0100
Subject: [PATCH] Remove duplicate intersections in #getIntersections

---
 src/path/PathItem.js | 54 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 52 insertions(+), 2 deletions(-)

diff --git a/src/path/PathItem.js b/src/path/PathItem.js
index 9ae3f2f0..5a76602e 100644
--- a/src/path/PathItem.js
+++ b/src/path/PathItem.js
@@ -59,7 +59,18 @@ var PathItem = Item.extend(/** @lends PathItem# */{
 	 * 	}
 	 * }
 	 */
-	getIntersections: function(path) {
+	getIntersections: function(path, expand) {
+		function compare(loc1, loc2) {
+			var path1 = loc1.getPath(),
+				path2 = loc2.getPath();
+			return path1 === path2
+					// We can add parameter (0 <= t <= 1) to index 
+					// (a integer) to compare both at the same time
+					? (loc1.getIndex() + loc1.getParameter())
+							- (loc2.getIndex() + loc2.getParameter())
+					// Sort by path id to group all locations on the same path.
+					: path1._id - path2._id;
+		}
 		// First check the bounds of the two paths. If they don't intersect,
 		// we don't need to iterate through their curves.
 		if (!this.getBounds().touches(path.getBounds()))
@@ -71,7 +82,10 @@ var PathItem = Item.extend(/** @lends PathItem# */{
 			matrix2 = path._matrix.orNullIfIdentity(),
 			length1 = curves1.length,
 			length2 = curves2.length,
-			values2 = [];
+			values2 = [],
+			tolerance = Numerical.EPSILON,
+			tolerance1 = 1 - tolerance,
+			abs = Math.abs;
 		for (var i = 0; i < length2; i++)
 			values2[i] = curves2[i].getValues(matrix2);
 		for (var i = 0; i < length1; i++) {
@@ -81,6 +95,42 @@ var PathItem = Item.extend(/** @lends PathItem# */{
 				Curve.getIntersections(values1, values2[j], curve1, curves2[j],
 						locations);
 		}
+		// Remove duplicate intersections near curve endings
+		var loc, locNext;
+		// Merge intersections very close to the end of a curve to the
+		// begining of the next curve
+		for (var i = locations.length-1; i >= 0; i--) {
+			loc = locations[i];
+			locNext = loc._curve.getNext();
+			if (loc._parameter >= tolerance1 && locNext) {
+				loc._parameter = 0;
+				loc._curve = locNext;
+			}
+			locNext = loc._curve2.getNext();
+			if (loc._parameter2 >= tolerance1 && locNext) {
+				loc._parameter2 = 0;
+				loc._curve2 = locNext;
+			}
+		}
+		locations.sort(compare);
+		for (var length1 = locations.length - 1, i = length1; i >= 0; i--) {
+			loc = locations[i];
+			locNext = (i === 0)? locations[length1] : locations[i-1];
+			if (abs(loc._parameter - locNext._parameter) < tolerance &&
+					loc._curve === locNext._curve &&
+					abs(loc._parameter2 - locNext._parameter2) < tolerance &&
+					loc._curve2 === locNext._curve2) {
+				locations.splice(i, 1);
+				--length1;
+			}
+		}
+		if (expand) {
+			for (var i = locations.length-1; i >= 0; i--) {
+				loc = locations[i];
+				locations.push(loc.getIntersection());
+			}
+			locations.sort(compare);
+		}
 		return locations;
 	},