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changed getIntersections #2038

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163 changes: 122 additions & 41 deletions src/path/Curve.js
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Original file line number Diff line number Diff line change
Expand Up @@ -2103,55 +2103,136 @@ new function() { // Scope for bezier intersection using fat-line clipping
return locations;
}

function getIntersections(curves1, curves2, include, matrix1, matrix2,
_returnFirst) {
var epsilon = /*#=*/Numerical.GEOMETRIC_EPSILON,
self = !curves2;
if (self)
curves2 = curves1;
var length1 = curves1.length,
length2 = curves2.length,
values1 = new Array(length1),
values2 = self ? values1 : new Array(length2),
locations = [];

for (var i = 0; i < length1; i++) {
values1[i] = curves1[i].getValues(matrix1);
function getIntersections(v) {
var curve1 = this,
curve2 = v,
epsilon = /*#=*/Numerical.EPSILON,
straight1 = curve1.isStraight(),
straight2 = curve2.isStraight(),
line1 = straight1 && new Line(curve1._segment1._point,
curve1._segment2._point),
line2 = straight2 && new Line(curve2._segment1._point,
curve2._segment2._point),
intersections = [];

function addIntersection(intersection) {
var t1 = intersection.parameter,
t2 = intersection.parameter2;
if (t1 >= -epsilon && t1 <= 1 + epsilon
&& t2 >= -epsilon && t2 <= 1 + epsilon) {
var existing = false;
for (var i = 0, l = intersections.length; i < l; i++) {
var entry = intersections[i];
if (entry.equals(intersection)) {
existing = true;
break;
}
}
if (!existing) {
intersections.push(intersection);
}
}
}
if (!self) {
for (var i = 0; i < length2; i++) {
values2[i] = curves2[i].getValues(matrix2);

function addCurveIntersections(v, locations, include) {
var flip = Curve.isStraight(v),
point = flip ? v.getPointAt(0.5) : null;
for (var i = 0, l = locations.length; i < l; i++) {
var loc = locations[i];
if (flip
? point.getDistance(loc.getPoint()) < epsilon
: loc.getPath() === v._path) {
var t1 = loc.getTime(),
t2 = flip
? Curve.getParameterOf(v, loc.getPoint())
: Curve.getTimeOf(v, loc.getPoint());
if (include || !loc.isCrossing()) {
addIntersection(new Intersection(
include || loc.isTouching() ? 'touch' : 'cross',
t1, t2));
}
}
}
}
var boundsCollisions = CollisionDetection.findCurveBoundsCollisions(
values1, values2, epsilon);
for (var index1 = 0; index1 < length1; index1++) {
var curve1 = curves1[index1],
v1 = values1[index1];
if (self) {
// First check for self-intersections within the same curve.
getSelfIntersection(v1, curve1, locations, include);

function addLineIntersection(line, parameter) {
var point = line.getPointAt(parameter);
addIntersection(new Intersection('cross',
Curve.getParameterOf(curve1, point),
Curve.getParameterOf(curve2, point)));
}

function handleCollinearLines(line1, line2) {
var point1a = line1.getPointAt(0),
point1b = line1.getPointAt(1),
point2a = line2.getPointAt(0),
point2b = line2.getPointAt(1);
if (point1a.isClose(point2a, epsilon)) {
addLineIntersection(line1, 0);
} else if (point1a.isClose(point2b, epsilon)) {
addLineIntersection(line1, 0);
addLineIntersection(line2, 1);
} else if (point1b.isClose(point2a, epsilon)) {
addLineIntersection(line1, 1);
addLineIntersection(line2, 0);
} else if (point1b.isClose(point2b, epsilon)) {
addLineIntersection(line1, 1);
} else if (line1.getParameterOf(point2a) != null) {
addLineIntersection(line2, 0);
} else if (line1.getParameterOf(point2b) != null) {
addLineIntersection(line2, 1);
} else if (line2.getParameterOf(point1a) != null) {
addLineIntersection(line1, 0);
} else if (line2.getParameterOf(point1b) != null) {
addLineIntersection(line1, 1);
}
// Check for intersections with potentially intersecting curves.
var collisions1 = boundsCollisions[index1];
if (collisions1) {
for (var j = 0; j < collisions1.length; j++) {
// There might be already one location from the above
// self-intersection check:
if (_returnFirst && locations.length)
return locations;
var index2 = collisions1[j];
if (!self || index2 > index1) {
var curve2 = curves2[index2],
v2 = values2[index2];
getCurveIntersections(
v1, v2, curve1, curve2, locations, include);
}
}

function handleClipping() {
var vRes = curve2.getValues(),
prevT;

function clipConvex(vClip) {
var iClip = Intersection.intersect(vRes, vClip);
for (var i = 0; i < 4; i++) {
var tClip = iClip['time' + (i + 1)];
if (tClip == null)
break;
var tRes = iClip['time' + (i + 5)];
if (!(prevT <= tRes && tRes <= 1))
break;
prevT = tRes;
addIntersection(new Intersection('cross', tClip, tRes));
}
}

clipConvex(curve1.getPart(0.5 - epsilon).getValues());
clipConvex(curve1.getPart(0.5 + epsilon).getValues());
}
return locations;

// Handle special cases of straight lines and collinear lines.
if (straight1 && straight2) {
if (line1.isCollinear(line2)) {
handleCollinearLines(line1, line2);
} else {
var intersection = line1.intersect(line2, false);
if (intersection)
addLineIntersection(line1, line1.getParameterOf(intersection));
}
} else if (straight1) {
addCurveIntersections(curve2, line1.getIntersections(curve2));
} else if (straight2) {
addCurveIntersections(curve1, line2.getIntersections(curve1));
} else if (curve1.isCollinear(curve2)) {
handleCollinearLines(line1, line2);
} else {
// Use the clipper to handle the intersections.
prevT = -Infinity;
handleClipping();
}
return intersections;
}


/**
* Code to detect overlaps of intersecting based on work by
Expand Down