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https://github.com/scratchfoundation/paper.js.git
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Improve detection of start segments.
Segments with multiple intersections need to be checked thoroughly to avoid errors.
This commit is contained in:
Jürg Lehni
parent
e92a71e8c7
commit
c9eba83cc7
1 changed files with 47 additions and 19 deletions
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@ -586,6 +586,10 @@ PathItem.inject(new function() {
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return operator(winding);
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}
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function isStart(seg) {
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return seg === start || seg === otherStart;
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}
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/**
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* Checks if the curve from seg1 to seg2 is part of an overlap, by
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* getting a curve-point somewhere along the curve (t = 0.5), and
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@ -603,8 +607,9 @@ PathItem.inject(new function() {
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// If there are multiple possible intersections, find the one
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// that's either connecting back to start or is not visited yet,
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// and will be part of the boolean result:
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function getBestIntersection(inter, strict) {
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var begin = inter;
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function findBestIntersection(inter, strict) {
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if (!inter._next)
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return inter;
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while (inter) {
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var seg = inter._segment,
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nextSeg = seg.getNext(),
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@ -616,8 +621,7 @@ PathItem.inject(new function() {
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+ nextSeg._index
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+ ', seg vis:' + !!seg._visited
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+ ', next vis:' + !!nextSeg._visited
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+ ', next start:' + (nextSeg === start
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|| nextSeg === otherStart)
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+ ', next start:' + isStart(nextSeg)
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+ ', seg wi:' + seg._winding
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+ ', next wi:' + nextSeg._winding
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+ ', seg op:' + isValid(seg, true)
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@ -644,7 +648,7 @@ PathItem.inject(new function() {
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// result, the non-strict mode is used, in which invalid current
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// segments are tolerated, and overlaps for the next segment are
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// allowed as long as they are valid when not adjusted.
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if (nextSeg === start || nextSeg === otherStart
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if (isStart(nextSeg)
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|| !seg._visited && !nextSeg._visited
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// Self-intersections (!operator) don't need isValid() calls
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&& (!operator
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@ -669,16 +673,25 @@ PathItem.inject(new function() {
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return null;
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}
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function findStartSegment(inter, next) {
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while (inter) {
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var seg = inter._segment;
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if (isStart(seg))
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return seg;
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inter = inter[next ? '_next' : '_prev'];
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}
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}
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for (var i = 0, l = segments.length; i < l; i++) {
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var seg = segments[i],
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path = null;
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path = null,
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finished = false;
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// Do not start a chain with already visited segments, and segments
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// that are not going to be part of the resulting operation.
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if (!isValid(seg))
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continue;
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start = otherStart = null;
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// Loop until we're back at the start.
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while (seg !== start && seg !== otherStart) {
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while (!finished) {
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var inter = seg._intersection;
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// Once we started a chain, see if there are multiple
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// intersections, and if so, pick the best one:
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@ -691,8 +704,8 @@ PathItem.inject(new function() {
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+ ', other: ' + inter._segment._path._id + '.'
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+ inter._segment._index);
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}
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inter = inter && (getBestIntersection(inter, true)
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|| getBestIntersection(inter, false)) || inter;
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inter = inter && (findBestIntersection(inter, true)
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|| findBestIntersection(inter, false)) || inter;
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var other = inter && inter._segment;
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// A switched intersection means we may have changed the segment
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// Point to the other segment in the selected intersection.
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@ -737,13 +750,27 @@ PathItem.inject(new function() {
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drawSegment(seg, null, 'stay', i, 'blue');
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}
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if (seg._visited) {
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// TODO: || !isValid(seg) ?
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// We didn't manage to switch, so stop right here.
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console.error('Visited segment encountered, aborting #'
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+ pathCount + '.'
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+ (path ? path._segments.length + 1 : 1)
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+ ', id: ' + seg._path._id + '.' + seg._index
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+ ', multiple: ' + !!(inter && inter._next));
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if (isStart(seg)) {
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drawSegment(seg, null, 'done', i, 'red');
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finished = true;
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} else if (inter) {
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var found = findStartSegment(inter, true)
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|| findStartSegment(inter, false);
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if (found) {
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seg = found;
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drawSegment(seg, null, 'done multiple', i, 'red');
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finished = true;
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break;
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}
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}
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if (!finished) {
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// We didn't manage to switch, so stop right here.
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console.error('Visited segment encountered, aborting #'
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+ pathCount + '.'
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+ (path ? path._segments.length + 1 : 1)
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+ ', id: ' + seg._path._id + '.' + seg._index
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+ ', multiple: ' + !!(inter && inter._next));
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}
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break;
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}
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if (!path) {
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@ -756,15 +783,16 @@ PathItem.inject(new function() {
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path.add(new Segment(seg._point, handleIn, seg._handleOut));
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seg._visited = true;
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seg = seg.getNext();
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if (seg === start || seg === otherStart) {
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if (isStart(seg)) {
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drawSegment(seg, null, 'done', i, 'red');
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finished = true;
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}
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}
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if (!path)
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continue;
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// Finish with closing the paths if necessary, correctly linking up
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// curves etc.
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if (seg === start || seg === otherStart) {
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if (finished) {
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path.firstSegment.setHandleIn(seg._handleIn);
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path.setClosed(true);
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if (window.reportSegments) {
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