From 80f01d6b5912032688e1095ecbf5486ea6e16a79 Mon Sep 17 00:00:00 2001
From: Holmes Futrell <holmes@gingerlabs.com>
Date: Tue, 4 Jun 2019 11:31:10 -0700
Subject: [PATCH] test data from a real world case where roots was failing.

---
 BezierKit/BezierKitTests/UtilsTests.swift | 15 +++++++++++++++
 BezierKit/Library/PathComponent.swift     |  8 ++++----
 BezierKit/Library/Utils.swift             |  2 +-
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/BezierKit/BezierKitTests/UtilsTests.swift b/BezierKit/BezierKitTests/UtilsTests.swift
index f686fd34..6cd82fcf 100644
--- a/BezierKit/BezierKitTests/UtilsTests.swift
+++ b/BezierKit/BezierKitTests/UtilsTests.swift
@@ -24,4 +24,19 @@ class UtilsTests: XCTestCase {
         XCTAssertTrue(Utils.clamp(CGFloat.nan, -1.0, 1.0).isNaN)
     }
 
+    func testRootsRealWorldIssue() {
+        let points: [CGPoint] = [
+            CGPoint(x:523.4257521858988, y: 691.8949684622992),
+            CGPoint(x:523.1393916834338, y: 691.8714265856051),
+            CGPoint(x:522.8595588275791, y: 691.7501129962762),
+            CGPoint(x:522.6404735257349, y: 691.531027694432)
+        ]
+        let curve = CubicBezierCurve(points: points)
+        let y: CGFloat = 691.87778055040201
+        let line = LineSegment(p0: CGPoint(x: 0, y: y), p1: CGPoint(x: 1, y: y))
+        let r = Utils.roots(points: points, line: line)
+        let filtered = r.filter { $0 >= 0 && $0 <= 1 }
+        XCTAssertEqual(curve.compute(CGFloat(filtered[0])).y, y, accuracy: CGFloat(1.0e-5))
+    }
+
 }
diff --git a/BezierKit/Library/PathComponent.swift b/BezierKit/Library/PathComponent.swift
index 84a860e5..9999e106 100644
--- a/BezierKit/Library/PathComponent.swift
+++ b/BezierKit/Library/PathComponent.swift
@@ -402,11 +402,11 @@ import Foundation
         let d0 = p1.y - p0.y
         let d1 = p2.y - p1.y
         var last: CGFloat = 0.0
-        Utils.droots(d0, d1, callback: { t in
+        Utils.droots(d0, d1) { t in
             guard t > 0, t < 1 else { return }
             callback(curve.split(from: last, to: t))
             last = t
-        })
+        }
         if last < 1.0 {
             callback(curve.split(from: last, to: 1.0))
         }
@@ -422,11 +422,11 @@ import Foundation
         let d1 = p2.y - p1.y
         let d2 = p3.y - p2.y
         var last: CGFloat = 0.0
-        Utils.droots(d0, d1, d2, callback: { t in
+        Utils.droots(d0, d1, d2) { t in
             guard t > 0, t < 1 else { return }
             callback(curve.split(from: last, to: t))
             last = t
-        })
+        }
         if last < 1.0 {
             callback(curve.split(from: last, to: 1.0))
         }
diff --git a/BezierKit/Library/Utils.swift b/BezierKit/Library/Utils.swift
index 374d38ce..e7e4614b 100644
--- a/BezierKit/Library/Utils.swift
+++ b/BezierKit/Library/Utils.swift
@@ -185,7 +185,7 @@ internal class Utils {
             let temp2 = 3*pb
             let temp3 = -3*pc
             let d = temp1 + temp2 + temp3 + pd
-            let smallValue = 1.0e-10
+            let smallValue = 1.0e-8
             if abs(d) < smallValue {
                 let temp1 = 3*points[0]
                 let temp2 = -6*points[1]