From e2bc83af5d1c79db5d0212ac93c0d6176bbd263f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=BCrg=20Lehni?= <juerg@scratchdisk.com>
Date: Fri, 12 Feb 2016 20:19:40 +0100
Subject: [PATCH] Add test for #960 and improve fix a bit.
Closes #960
---
src/path/Curve.js | 8 ++++++--
test/tests/Curve.js | 10 ++++++++++
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/src/path/Curve.js b/src/path/Curve.js
index 4895da53..32a550ac 100644
--- a/src/path/Curve.js
+++ b/src/path/Curve.js
@@ -1338,8 +1338,12 @@ new function() { // Scope for methods that require private functions
if (type === 0) {
// type === 0: getPoint()
// Calculate the curve point at parameter value t
- x = t === 1 ? p2x : ((ax * t + bx) * t + cx) * t + p1x;
- y = t === 1 ? p2y : ((ay * t + by) * t + cy) * t + p1y;
+ // Use special handling at t === 0 / 1, to avoid imprecisions.
+ // See #960
+ x = t === 0 ? p1x : t === 1 ? p2x
+ : ((ax * t + bx) * t + cx) * t + p1x;
+ y = t === 0 ? p1y : t === 1 ? p2y
+ : ((ay * t + by) * t + cy) * t + p1y;
} else {
// type === 1: getTangent()
// type === 2: getNormal()
diff --git a/test/tests/Curve.js b/test/tests/Curve.js
index c03ccf35..7139e437 100644
--- a/test/tests/Curve.js
+++ b/test/tests/Curve.js
@@ -37,6 +37,16 @@ test('Curve#getPointAtTime()', function() {
equals(curve.getPointAt(curve.length + 1), null,
'Should return null when offset is out of range.');
+
+ // #960:
+ var curve = new Curve({
+ segment1: [178.58559999999994, 333.41440000000006],
+ segment2: [178.58559999999994, 178.58560000000008]
+ });
+ equals(curve.getPointAtTime(0).y, curve.point1.y,
+ 'Point at t=0 should not deviate from the actual coordinates.');
+ equals(curve.getPointAtTime(1).y, curve.point2.y,
+ 'Point at t=1 should not deviate from the actual coordinates.');
});
test('Curve#getTangentAtTime()', function() {