From 6cdead0e8c755c7ba9c75238be9806f482034b86 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=BCrg=20Lehni?= <juerg@scratchdisk.com>
Date: Sun, 11 Oct 2015 16:56:41 +0200
Subject: [PATCH] Add fallback strategy when ending up in a dead-end in
tracePaths().
This simple fix appears to be able to catch quite a few glitches with very small curves.
---
src/path/PathItem.Boolean.js | 46 ++++++++++++++++++++++++++++--------
1 file changed, 36 insertions(+), 10 deletions(-)
diff --git a/src/path/PathItem.Boolean.js b/src/path/PathItem.Boolean.js
index 1ab769fa..b116df36 100644
--- a/src/path/PathItem.Boolean.js
+++ b/src/path/PathItem.Boolean.js
@@ -751,36 +751,62 @@ PathItem.inject(new function() {
drawSegment(seg, null, 'stay', i, 'blue');
}
if (seg._visited) {
- if (isStart(seg)) {
+ finished = isStart(seg);
+ if (finished) {
drawSegment(seg, null, 'done', i, 'red');
- finished = true;
- } else if (inter) {
+ }
+ if (!finished && inter) {
var found = findStartSegment(inter, true)
|| findStartSegment(inter, false);
+ // This should not happen but due to numerical
+ // imprecisions we sometimes end up in a dead-end. See
+ // if we can find a way out by checking all valid
+ // segments to find one that's close enough.
+ for (var j = 0; !found && j < l; j++) {
+ var seg2 = segments[j];
+ // Do not start a chain with already visited
+ // segments, and segments that are not going to
+ // be part of the resulting operation.
+ if (seg !== seg2
+ && seg._point.isClose(seg2._point,
+ /*#=*/Numerical.GEOMETRIC_EPSILON)
+ && (isStart(seg2) || isValid(seg2))) {
+ found = seg2;
+ }
+ }
if (found) {
seg = found;
- drawSegment(seg, null, 'done multiple', i, 'red');
- finished = true;
- break;
+ finished = isStart(seg);
+ if (window.reportSegments) {
+ console.log('Switching to: ',
+ seg._path._id + '.' + seg._index);
+ }
+ if (finished) {
+ drawSegment(seg, null, 'done inter', i, 'red');
+ }
}
}
- if (!finished) {
+ if (finished)
+ break;
+ if (!isValid(seg)) {
// We didn't manage to switch, so stop right here.
console.error('Visited segment encountered, aborting #'
+ pathCount + '.'
+ (path ? path._segments.length + 1 : 1)
+ ', id: ' + seg._path._id + '.' + seg._index
+ ', multiple: ' + !!(inter && inter._next));
+ break;
}
- break;
}
if (!path) {
path = new Path(Item.NO_INSERT);
start = seg;
otherStart = other;
}
- // Add the current segment to the path, and mark the added
- // segment as visited.
+ if (window.reportSegments) {
+ console.log('Adding', seg._path._id + '.' + seg._index);
+ }
+ // Add the segment to the path, and mark it as visited.
path.add(new Segment(seg._point, handleIn, seg._handleOut));
seg._visited = true;
seg = seg.getNext();