scratchfoundation/paper.js
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New Split path method

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hkrish 2013-12-29 13:25:48 +01:00
parent 1be669396e
commit 7c75dcee97
1 changed files with 81 additions and 0 deletions
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src/path/PathItem.js
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@ -283,6 +283,87 @@ var PathItem = Item.extend(/** @lends PathItem# */{
var winding = this._getWinding(point);
return !!(this.getWindingRule() === 'evenodd' ? winding & 1 : winding);
/*#*/ } // !__options.nativeContains
},
statics: {
/**
* Private method for splitting a PathItem at the given intersections.
* The routine works for both self intersections and intersections
* between PathItems.
* @param {Array} intersections Array of CurveLocation objects
*/
_splitPath: function(intersections) {
function compare(loc1, loc2) {
var path1 = loc1.getPath(),
path2 = loc2.getPath();
return path1 === path2
// We can add parameter (0 <= t <= 1) to index
// (a integer) to compare both at the same time
? (loc1.getIndex() + loc1.getParameter())
- (loc2.getIndex() + loc2.getParameter())
// Sort by path id to group all locations on the same path.
: path1._id - path2._id;
}
var loc, i, j, node1, node2, t, segment,
path1, isLinear, crv, crvNew,
newSegments = [],
tolerance = /*#=*/ Numerical.EPSILON;
// Make a binary heap of all intersections
for (i = intersections.length - 1; i >= 0; i--) {
loc = intersections[i];
intersections.push(loc.getIntersection());
}
intersections.sort(compare);
for (i = intersections.length - 1; i >= 0; i--) {
node1 = intersections[i];
path1 = node1.getPath();
// Check if we are splitting same curve multiple times
if (node2 && node2.getPath() === path1 &&
node2._curve === node1._curve) {
// Use the result of last split and interpolate the parameter.
crv = crvNew;
t = node1._parameter / node2._parameter;
} else {
crv = node1._curve;
t = node1._parameter;
isLinear = crv.isLinear();
newSegments.length = 0;
}
// Split the curve at t, while ignoring linearity of curves
if ((crvNew = crv.divide(t, true, true)) === null){
if (t >= 1-tolerance) {
segment = crv._segment2;
} else if (t <= tolerance) {
segment = crv._segment1;
} else {
// Determine the closest segment by comparing curve lengths
segment = crv.getLength(0, t) < crv.getLength(t, 1)
? crv._segment1 : crv._segment2;
}
crvNew = crv;
} else {
segment = crvNew.getSegment1();
crvNew = crvNew.getPrevious();
}
// Link the new segment with the intersection on the other curve
segment._intersection = node1.getIntersection();
node1._segment = segment;
node2 = node1;
// Reset linear segments if they were part of a linear curve
// and if we are done with the entire curve.
newSegments.push(segment);
loc = intersections[i - 1];
if (!(loc && loc.getPath() === path1 &&
loc._curve === node1._curve) && isLinear)
for (j = newSegments.length-1; j >= 0; j--) {
segment = newSegments[j];
segment._handleOut.set(0, 0);
segment._handleIn.set(0, 0);
}
}
},
/**
* Private static method that returns the winding contribution of the
* given point with respect to a given set of monotone curves