gistfile1.js

function interPathHelper(path1, path2, justCount) {
        path1 = R._path2curve(path1);
        path2 = R._path2curve(path2);
        var x1, y1, x2, y2, x1m, y1m, x2m, y2m, bez1, bez2,
            res = justCount ? 0 : [];
        for (var i = 0, ii = path1.length; i < ii; i++) {
            var pi = path1[i];
            if (pi[0] == "M") {
                x1 = x1m = pi[1];
                y1 = y1m = pi[2];
            } else {
                if (pi[0] == "C") {
                    bez1 = [x1, y1].concat(pi.slice(1));
                    x1 = bez1[6];
                    y1 = bez1[7];
                } else {
                    bez1 = [x1, y1, x1, y1, x1m, y1m, x1m, y1m];
                    x1 = x1m;
                    y1 = y1m;
                }
                for (var j = 0, jj = path2.length; j < jj; j++) {
                    var pj = path2[j];
                    if (pj[0] == "M") {
                        x2 = x2m = pj[1];
                        y2 = y2m = pj[2];
                    } else {
                        if (pj[0] == "C") {
                            bez2 = [x2, y2].concat(pj.slice(1));
                            x2 = bez2[6];
                            y2 = bez2[7];
                        } else {
                            bez2 = [x2, y2, x2, y2, x2m, y2m, x2m, y2m];
                            x2 = x2m;
                            y2 = y2m;
                        }
                        var intr = interHelper(bez1, bez2, justCount);
                        if (justCount) {
                            res += intr;
                        } else {
                            for (var k = 0, kk = intr.length; k < kk; k++) {
                                intr[k].segment1 = i;
                                intr[k].segment2 = j;
                                intr[k].bez1 = bez1;
                                intr[k].bez2 = bez2;
                            }
                            res = res.concat(intr);
                        }
                    }
                }
            }
        }
        return res;
    }