mirror of
https://github.com/scratchfoundation/paper.js.git
synced 2025-01-03 19:45:44 -05:00
Second attempt at simplifying boolean code.
This time without endless loops.
This commit is contained in:
Jürg Lehni
parent
089738478c
commit
3ce7d88347
1 changed files with 44 additions and 79 deletions
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@ -148,7 +148,7 @@ PathItem.inject(new function() {
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tracePaths(segments, monoCurves, operation), path1, path2);
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}
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var scaleFactor = 1 / 3000; // 0.5; // 1 / 3000;
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var scaleFactor = 1; // 1 / 3000;
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var textAngle = 60;
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var fontSize = 5;
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@ -448,7 +448,7 @@ PathItem.inject(new function() {
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*/
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function tracePaths(segments, monoCurves, operation) {
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var segmentCount = 0;
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var pathCount = 0;
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var pathCount = 1;
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function labelSegment(seg, text, color) {
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var point = seg.point;
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@ -481,7 +481,7 @@ PathItem.inject(new function() {
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strokeScaling: false
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});
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var inter = seg._intersection;
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labelSegment(seg, '#' + (pathCount + 1) + '.'
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labelSegment(seg, '#' + pathCount + '.'
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+ (path ? path._segments.length + 1 : 1)
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+ ' ' + (segmentCount++) + '/' + index + ': ' + text
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+ ' v: ' + !!seg._visited
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@ -534,107 +534,74 @@ PathItem.inject(new function() {
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inter = seg._intersection,
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otherSeg = inter && inter._segment,
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otherStartSeg = otherSeg,
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added = false, // Whether a first segment as added already
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dir = 1;
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added = false; // Whether a first segment as added already
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do {
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var handleIn = dir > 0 ? seg._handleIn : seg._handleOut;
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// If the intersection segment is valid, try switching to
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// it, with an appropriate direction to continue traversal.
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// Else, stay on the same contour.
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var handleIn = added && seg._handleIn;
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if (added && otherSeg && otherSeg !== startSeg) {
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// There is an intersection. If the intersecting segment is
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// valid, try switching to it to continue traversal.
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// Otherwise stay on the same contour.
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if (otherSeg._path === seg._path) { // Self-intersection
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drawSegment(seg, 'self-int ' + dir, i, 'red');
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// Switch to the intersection segment, as we need to
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drawSegment(seg, 'self-int', i, 'red');
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// Switch to the intersecting segment, as we need to
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// resolving self-Intersections.
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seg = otherSeg;
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dir = 1;
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} else if (operation !== 'exclude' && operator(seg._winding)) {
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// Do not switch to the intersection as the segment is
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// part of the boolean result.
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drawSegment(seg, 'keep', i, 'black');
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} else if (operation !== 'exclude'
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&& operator(seg._winding)) {
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// Do not switch to the intersecting segment as it is
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// contained inside the boolean result.
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drawSegment(seg, 'ignore-keep', i, 'black');
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} else if (operation !== 'intersect' && inter._overlap) {
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// Switch to the overlapping intersection segment
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// if its winding number along the curve is 1, to
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// leave the overlapping area.
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// NOTE: We cannot check the next (overlapping)
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// segment since its winding number will always be 2
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drawSegment(seg, 'overlap ' + dir, i, 'orange');
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drawSegment(seg, 'overlap', i, 'orange');
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var curve = otherSeg.getCurve();
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if (getWinding(curve.getPointAt(0.5, true),
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monoCurves, curve.isHorizontal()) === 1) {
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seg = otherSeg;
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dir = 1;
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}
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} else {
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var c1 = seg.getCurve();
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if (dir > 0)
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c1 = c1.getPrevious();
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var t1 = c1.getTangentAt(dir < 0 ? tMin : tMax, true),
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// Get both curves at the intersection
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// (except the entry curves).
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c4 = otherSeg.getCurve(),
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c3 = c4.getPrevious(),
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// Calculate their winding values and tangents.
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t3 = c3.getTangentAt(tMax, true),
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t4 = c4.getTangentAt(tMin, true),
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// Cross product of the entry and exit tangent
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// vectors at the intersection, will let us select
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// the correct contour to traverse next.
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w3 = t1.cross(t3),
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w4 = t1.cross(t4);
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if (Math.abs(w3 * w4) < /*#=*/Numerical.EPSILON) {
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drawSegment(seg, 'no cross', i, 'blue');
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dir = 1; // TODO: Why? Is this correct?
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} else if (operation === 'exclude') {
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} else if (operation === 'exclude'
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|| operator(otherSeg._winding)) {
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// Look at both tangents at the intersection to
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// determine if this intersection is actually a crossing
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var t1 = seg.getPrevious().getCurve().getTangentAt(tMax, true),
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t2 = otherSeg.getCurve().getTangentAt(tMin, true);
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if (t1.isCollinear(t2)) {
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// Do not attempt to switch contours if we aren't
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// sure that there is a possible candidate.
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// If we didn't find a suitable direction for next
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// contour to traverse, stay on the same contour.
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drawSegment(seg, 'no cross', i, 'blue');
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} else {
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// Switch to the intersection segment.
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seg = otherSeg;
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drawSegment(seg, 'exclude:switch', i, 'green');
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dir = 1;
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} else {
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// Do not attempt to switch contours if we aren't
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// sure that there is a possible candidate.
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var curve = w3 < w4 ? c3 : c4;
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if (!operator(curve._segment1._winding))
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curve = curve === c3 ? c4 : c3;
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dir = curve === c3 ? -1 : 1;
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var next = curve._segment1;
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// If we didn't find a suitable direction for next
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// contour to traverse, stay on the same contour.
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if (next._visited && seg._path !== next._path
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|| !operator(next._winding)) {
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drawSegment(next, 'not suitable', i, 'orange');
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dir = 1;
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} else {
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// Switch to the intersection segment.
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seg = otherSeg;
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if (next._visited)
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dir = -dir;
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drawSegment(seg, 'switch', i, 'green');
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}
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drawSegment(seg, 'switch', i, 'green');
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}
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} else {
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drawSegment(otherSeg, 'not suitable', i, 'orange');
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}
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} else {
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drawSegment(seg, 'keep', i, 'black');
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}
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if (seg._visited) {
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// We didn't manage to switch, so stop right here.
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console.error('Unable to switch to intersecting segment, '
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+ 'aborting #' + pathCount + '.' +
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(path ? path._segments.length + 1 : 1));
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break;
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}
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// Add the current segment to the path, and mark the added
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// segment as visited.
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path.add(new Segment(seg._point, added && handleIn,
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dir > 0 ? seg._handleOut : seg._handleIn));
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seg._visited = true;
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added = true;
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// Move to the next segment according to the traversal direction
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seg = dir > 0 ? seg.getNext() : seg.getPrevious();
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path.add(new Segment(seg._point, handleIn, seg._handleOut));
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seg._visited = added = true;
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seg = seg.getNext();
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inter = seg && seg._intersection;
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otherSeg = inter && inter._segment;
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} while (seg && seg !== startSeg && seg !== otherStartSeg
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// Exclusion switches on each intersection, we need to look
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// ahead & carry on if the other segment wasn't visited yet.
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&& (!seg._visited || operation === 'exclude'
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&& otherSeg && !otherSeg._visited)
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// If we're about to switch, try to see if we can carry on
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// if the other segment wasn't visited yet.
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&& (!seg._visited || otherSeg && !otherSeg._visited)
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&& (inter || operator(seg._winding)));
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// Finish with closing the paths if necessary, correctly linking up
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// curves etc.
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@ -643,14 +610,14 @@ PathItem.inject(new function() {
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path.setClosed(true);
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if (window.reportSegments) {
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console.log('Boolean operation completed',
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'#' + (pathCount + 1) + '.' +
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'#' + pathCount + '.' +
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(path ? path._segments.length + 1 : 1));
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}
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} else {
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// path.lastSegment._handleOut.set(0, 0);
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console.error('Boolean operation results in open path, segs =',
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path._segments.length, 'length = ', path.getLength(),
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'#' + (pathCount + 1) + '.' +
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'#' + pathCount + '.' +
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(path ? path._segments.length + 1 : 1));
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path = null;
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}
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@ -661,9 +628,7 @@ PathItem.inject(new function() {
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if (path && (path._segments.length > 4
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|| !Numerical.isZero(path.getArea())))
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paths.push(path);
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if (window.reportSegments) {
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pathCount++;
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}
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pathCount++;
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}
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return paths;
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}
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