scratchfoundation/paper.js
1
0
Fork 0
mirror of https://github.com/scratchfoundation/paper.js.git synced 2025-01-19 06:00:56 -05:00
Code Issues Projects Releases Packages Wiki Activity Actions

Clean up propagateWinding() a bit.

Browse source
This commit is contained in:
Jürg Lehni 2016-01-08 10:54:11 +01:00
parent 34a173ee18
commit abafc886cd
1 changed files with 14 additions and 21 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

35
src/path/PathItem.Boolean.js
View file

@ -416,10 +416,10 @@ PathItem.inject(new function() {
}
function propagateWinding(segment, path1, path2, monoCurves, operator) {
// Here we try to determine the most probable winding number
// contribution for the curve-chain starting with this segment. Once we
// have enough confidence in the winding contribution, we can propagate
// it until the next intersection or end of a curve chain.
// Here we try to determine the most likely winding number contribution
// for the curve-chain starting with this segment. Once we have enough
// confidence in the winding contribution, we can propagate it until the
// next intersection or end of a curve chain.
var epsilon = /*#=*/Numerical.GEOMETRIC_EPSILON,
chain = [],
start = segment,
@ -433,21 +433,15 @@ PathItem.inject(new function() {
segment = segment.getNext();
} while (segment && !segment._intersection && segment !== start);
// Calculate the average winding among three evenly distributed points
// along this curve chain as a representative winding number. This
// selection gives a better chance of returning a correct winding than
// equally dividing the curve chain, with the same (amortized) time.
// along this curve chain as a representative winding number.
for (var i = 0; i < 3; i++) {
// Sample the points at 1/4, 2/4 and 3/4 of the total length:
// Sample the points at 3 equal intervals along the total length:
var length = totalLength * (i + 1) / 4;
for (var k = 0, m = chain.length; k < m; k++) {
var node = chain[k],
curveLength = node.length;
for (var j = 0, l = chain.length; j < l; j++) {
var entry = chain[j],
curveLength = entry.length;
if (length <= curveLength) {
// If the selected location on the curve falls onto its
// beginning or end, use the curve's center instead.
if (length < epsilon || curveLength - length < epsilon)
length = curveLength / 2;
var curve = node.curve,
var curve = entry.curve,
path = curve._path,
parent = path._parent,
t = curve.getParameterAt(length),
@ -459,11 +453,10 @@ PathItem.inject(new function() {
// While subtracting, we need to omit this curve if it is
// contributing to the second operand and is outside the
// first operand.
windingSum += operator.subtract && path2
&& (path === path1 && path2._getWinding(pt, hor)
|| path === path2 && !path1._getWinding(pt, hor))
? 0
: getWinding(pt, monoCurves, hor);
if (!(operator.subtract && path2
&& (path === path1 && path2._getWinding(pt, hor)
|| path === path2 && !path1._getWinding(pt, hor))))
windingSum += getWinding(pt, monoCurves, hor);
break;
}
length -= curveLength;