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isCrossing() needs parameter checks on both curves.

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This commit is contained in:
Jürg Lehni 2015-09-18 22:26:09 +02:00
parent b5af47a7b1
commit a95ba12bc3
1 changed files with 24 additions and 4 deletions
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28
src/path/CurveLocation.js
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@ -289,20 +289,23 @@ var CurveLocation = Base.extend(/** @lends CurveLocation# */{
return t1 && t2 ? t1.isCollinear(t2) : false;
},
isCrossing: function() {
isCrossing: function(_report) {
// Implementation based on work by Andy Finnell:
// http://losingfight.com/blog/2011/07/09/how-to-implement-boolean-operations-on-bezier-paths-part-3/
// https://bitbucket.org/andyfinnell/vectorboolean
var inter = this._intersection;
if (!inter)
return false;
var t = this._parameter,
// TODO: Make getCurve() and getParameter() sync work in boolean ops
// before and after splitting!!!
var t1 = this._parameter,
t2 = inter._parameter,
tMin = /*#=*/Numerical.CURVETIME_EPSILON,
tMax = 1 - tMin;
// If the intersection is in the middle of the path, it is either a
// tangent or a crossing, no need for the detailed corner check below.
// But we do need a check for the edge case of tangents?
if (t >= tMin && t <= tMax)
if (t1 >= tMin && t1 <= tMax || t2 >= tMin && t2 <= tMax)
return !this.isTangent();
// Values for getTangentAt() that are almost 0 and 1.
// NOTE: Even though getTangentAt() has code to support 0 and 1 instead
@ -310,7 +313,6 @@ var CurveLocation = Base.extend(/** @lends CurveLocation# */{
// emerge from switching to 0 and 1 in edge cases.
// NOTE: VectorBoolean has code that slowly shifts these points inwards
// until the resulting tangents are not ambiguous. Do we need this too?
// TODO: Make getCurve() sync work in boolean ops after splitting!!!
var c2 = this._curve,
c1 = c2.getPrevious(),
c4 = inter._curve,
@ -319,6 +321,24 @@ var CurveLocation = Base.extend(/** @lends CurveLocation# */{
if (!c1 || !c3)
return false;
if (_report) {
new Path.Circle({
center: this.getPoint(),
radius: 10,
strokeColor: 'red'
});
new Path({
segments: [c1.getSegment1(), c1.getSegment2(), c2.getSegment2()],
strokeColor: 'red',
strokeWidth: 4
});
new Path({
segments: [c3.getSegment1(), c3.getSegment2(), c4.getSegment2()],
strokeColor: 'orange',
strokeWidth: 4
});
}
function isInRange(angle, min, max) {
return min < max
? angle > min && angle < max