This is good mind-exercise.
What I've come up with below will let you know whether your single path's entire set of anchor points is located wholly within a closed bezier path.
What you need to do to start working on it is make a document, make your containing ellipse and call it "mycir" and test out a path called "mypth". The script gets a bezier interpolated point-polygon from the ellipse and uses the raycasting to check anchors of a test path to see if all are inside. Of course you may already see the problem of parts of your curve which are not anchors overlapping the ellipse and not being detected. If that's such a big problem, you will need to change the process to create the bezier polygon of your test path and check that with the raycasting. And that's just for one path- to do an entire group, yes, you'll need to adapt it to work on a whole group of paths. One more thing- this is really based on points.. so if your group has.. some effects, or appearance which really goes outside the boundaries, you'll definitely need to find a way to expand those to find your true boundaries, and raster effects may be a real deal-breaker.
#target illustrator
function test () {
if (!Array.prototype.indexOf) {
Array.prototype.indexOf = function(searchElement, fromIndex) {
var k;
if (this == null) {
throw new TypeError('"this" is null or not defined');
}
var o = Object(this);
var len = o.length >>> 0;
if (len === 0) {
return -1;
}
var n = +fromIndex || 0;
if (Math.abs(n) === Infinity) {
n = 0;
}
if (n >= len) {
return -1;
}
k = Math.max(n >= 0 ? n : len - Math.abs(n), 0);
while (k < len) {
if (k in o && o[k] === searchElement) {
return k;
}
k++;
}
return -1;
};
};
function foreach (arr, func) {
for (var i = 0; i < arr.length; i++) {
func(arr[i]);
}
}
function marker (xy, container) {
var container = container || doc;
var z = container.pathItems.ellipse(xy[1] + 2, xy[0] - 2, 4, 4);
z.stroked = false;
z.filled = true;
z.fillColor = clr;
}
function getPathPoints (path) { // collects pathPoints of a path into segment arrays of 2 anchors & 2 controls between them
var arr = [];
for (var i = 0, ln = path.pathPoints.length; i < ln; i++) { // designed to work on closed paths!
if (i < ln - 1) {
var p = path.pathPoints[i], pnext = path.pathPoints[i + 1];
} else {
var p = path.pathPoints[i], pnext = path.pathPoints[0];
}
arr.push([p.anchor, p.rightDirection, pnext.leftDirection, pnext.anchor]);
}
return arr;
}
function getBezierSegment (segArr) { // turns a pathPoint segment (gotten with getPathPoints) into bezier interpolated points
var anch2 = segArr[3], cont2 = segArr[2], cont1 = segArr[1], anch1 = segArr[0];
var resultPts = [];
var a = anch2[0] - 3 * (cont2[0]) + 3 * (cont1[0]) - anch1[0];
var b = 3 * (cont2[0]) - 6 * (cont1[0]) + 3 * anch1[0];
var c = 3 * (cont1[0]) - 3 * (anch1[0]);
var d = anch1[0];
var e = anch2[1] - 3 * (cont2[1]) + 3 * (cont1[1]) - anch1[1];
var f = 3 * (cont2[1]) - 6 * (cont1[1]) + 3 * anch1[1];
var g = 3 * (cont1[1]) - 3 * (anch1[1]);
var h = anch1[1];
var inc = 0.1;
for (var t = 0; t < 1; t += inc) {
resultPts.push([
a * Math.pow(t, 3) + b * Math.pow(t, 2) + (c * t) + d,
e * Math.pow(t, 3) + f * Math.pow(t, 2) + (g * t) + h
]);
}
return resultPts;
}
function getBezierPath (pathPts) { // turns entire series of segments (gotten with getPathPoints) into a complete set of interpolated bezier points
var pathArr = [];
for (var i = 0; i < pathPts.length; i++) {
var thisPtSet = pathPts[i];
var seg = getBezierSegment(thisPtSet);
if (
i > 0 && (seg[0][0] == pathArr[pathArr.length - 1][0] &&
seg[0][1] == pathArr[pathArr.length - 1][1])
) {
seg.splice(0, 1);
}
pathArr = pathArr.concat(seg);
}
return pathArr;
}
function markBezierPoints (seg) {
var grp = doc.groupItems.add();
grp.name = "MyGroup";
for (var i = 0; i < seg.length; i++) {
marker(seg, grp);
}
}
function makePolygon (pts) {
var pth = doc.pathItems.add();
pth.setEntirePath(pts);
pth.filled = false;
pth.stroked = true;
pth.strokeColor = clr;
pth.strokeWidth = 1;
}
var RayCaster = { // the whole raycasting through polygon algorithm from http://rosettacode.org/wiki/Ray-casting_algorithm
// evaluates a single point to see if it's inside a polygon.
Point : function (x, y) {
this.x = x;
this.y = y;
},
pointInPoly : function (point, poly) {
var index, intersected, pointA, pointB, segment, segments;
segments = (function () {
var _i, _len, _results;
_results = [];
for (index = 0, _len = poly.length; index < _len; index++) {
pointA = poly[index];
pointB = poly[(index + 1) % poly.length];
_results.push([new RayCaster.Point(pointA[0], pointA[1]), new RayCaster.Point(pointB[0], pointB[1])]);
}
return _results;
})();
intersected = (function () {
var _i, _len, _results;
_results = [];
for (_i = 0, _len = segments.length; _i < _len; _i++) {
segment = segments[_i];
if (
RayCaster.rayIntersectsSegment(new RayCaster.Point(point[0], point[1]), segment)
) {
_results.push(segment);
}
}
return _results;
})();
return intersected.length % 2 !== 0;
},
rayIntersectsSegment : function (p, segment) {
var a, b, mAB, mAP, p1, p2, _ref;
p1 = segment[0], p2 = segment[1];
_ref = p1.y < p2.y ? [p1, p2] : [p2, p1], a = _ref[0], b = _ref[1];
if (p.y === b.y || p.y === a.y) {
p.y += Number.MIN_VALUE;
}
if (p.y > b.y || p.y < a.y) {
return false;
} else if (p.x > a.x && p.x > b.x) {
return false;
} else if (p.x < a.x && p.x < b.x) {
return true;
} else {
mAB = (b.y - a.y) / (b.x - a.x);
mAP = (p.y - a.y) / (p.x - a.x);
return mAP > mAB;
}
}
};
function pathAnchorsInPoly (myPath, polyPts) {
var flag = false;
var all = [];
foreach(myPath.pathPoints, function (arg) {
if (RayCaster.pointInPoly(arg.anchor, polyPts) === false) {
all.push(false);
}
all.push(true);
});
flag = (all.indexOf(false) != -1) ? false : true;
if (flag === false) {
alert("NOT All Path Anchors are inside containing ellipse.");
} else {
alert("Yay! All Path Anchors are INSIDE the containing ellipse!");
}
return flag; // for use later (?)
}
if (app == "[Application Adobe Illustrator]" && app.documents.length > 0) {
app.coordinateSystem = CoordinateSystem.ARTBOARDCOORDINATESYSTEM;
var clr = new CMYKColor();
clr.cyan = 0;
clr.magenta = 100;
clr.yellow = 100;
clr.black = 0;
var doc = app.activeDocument;
try {
var m = doc.pathItems.getByName('mycir'); // my circle
var mp = doc.pathItems.getByName('mypth'); // my test path
} catch (e) {
alert("Put 2 paths into a document: a containing ellipse, name it 'mycir', and some random path- name it 'mypth'. Then run.");
return;
}
var pts = getPathPoints(m);
var bezPts = getBezierPath(pts);
// testing functions:
// markBezierPoints(bezPts);
// makePolygon(bezPts);
// foreach(bezPts, function(arg) {$.writeln(arg)});
pathAnchorsInPoly(mp, bezPts);
}
}
test();
1 Correct answer
16
Replies
AdChoices