CasperSecurity
'use strict';
/**
* @typedef {import('../lib/types').XastElement} XastElement
* @typedef {import('../lib/types').PathDataItem} PathDataItem
*/
const { parsePathData, stringifyPathData } = require('../lib/path.js');
/**
* @type {[number, number]}
*/
var prevCtrlPoint;
/**
* Convert path string to JS representation.
*
* @type {(path: XastElement) => Array<PathDataItem>}
*/
const path2js = (path) => {
// @ts-ignore legacy
if (path.pathJS) return path.pathJS;
/**
* @type {Array<PathDataItem>}
*/
const pathData = []; // JS representation of the path data
const newPathData = parsePathData(path.attributes.d);
for (const { command, args } of newPathData) {
pathData.push({ command, args });
}
// First moveto is actually absolute. Subsequent coordinates were separated above.
if (pathData.length && pathData[0].command == 'm') {
pathData[0].command = 'M';
}
// @ts-ignore legacy
path.pathJS = pathData;
return pathData;
};
exports.path2js = path2js;
/**
* Convert relative Path data to absolute.
*
* @type {(data: Array<PathDataItem>) => Array<PathDataItem>}
*
*/
const convertRelativeToAbsolute = (data) => {
/**
* @type {Array<PathDataItem>}
*/
const newData = [];
let start = [0, 0];
let cursor = [0, 0];
for (let { command, args } of data) {
args = args.slice();
// moveto (x y)
if (command === 'm') {
args[0] += cursor[0];
args[1] += cursor[1];
command = 'M';
}
if (command === 'M') {
cursor[0] = args[0];
cursor[1] = args[1];
start[0] = cursor[0];
start[1] = cursor[1];
}
// horizontal lineto (x)
if (command === 'h') {
args[0] += cursor[0];
command = 'H';
}
if (command === 'H') {
cursor[0] = args[0];
}
// vertical lineto (y)
if (command === 'v') {
args[0] += cursor[1];
command = 'V';
}
if (command === 'V') {
cursor[1] = args[0];
}
// lineto (x y)
if (command === 'l') {
args[0] += cursor[0];
args[1] += cursor[1];
command = 'L';
}
if (command === 'L') {
cursor[0] = args[0];
cursor[1] = args[1];
}
// curveto (x1 y1 x2 y2 x y)
if (command === 'c') {
args[0] += cursor[0];
args[1] += cursor[1];
args[2] += cursor[0];
args[3] += cursor[1];
args[4] += cursor[0];
args[5] += cursor[1];
command = 'C';
}
if (command === 'C') {
cursor[0] = args[4];
cursor[1] = args[5];
}
// smooth curveto (x2 y2 x y)
if (command === 's') {
args[0] += cursor[0];
args[1] += cursor[1];
args[2] += cursor[0];
args[3] += cursor[1];
command = 'S';
}
if (command === 'S') {
cursor[0] = args[2];
cursor[1] = args[3];
}
// quadratic Bézier curveto (x1 y1 x y)
if (command === 'q') {
args[0] += cursor[0];
args[1] += cursor[1];
args[2] += cursor[0];
args[3] += cursor[1];
command = 'Q';
}
if (command === 'Q') {
cursor[0] = args[2];
cursor[1] = args[3];
}
// smooth quadratic Bézier curveto (x y)
if (command === 't') {
args[0] += cursor[0];
args[1] += cursor[1];
command = 'T';
}
if (command === 'T') {
cursor[0] = args[0];
cursor[1] = args[1];
}
// elliptical arc (rx ry x-axis-rotation large-arc-flag sweep-flag x y)
if (command === 'a') {
args[5] += cursor[0];
args[6] += cursor[1];
command = 'A';
}
if (command === 'A') {
cursor[0] = args[5];
cursor[1] = args[6];
}
// closepath
if (command === 'z' || command === 'Z') {
cursor[0] = start[0];
cursor[1] = start[1];
command = 'z';
}
newData.push({ command, args });
}
return newData;
};
/**
* @typedef {{ floatPrecision?: number, noSpaceAfterFlags?: boolean }} Js2PathParams
*/
/**
* Convert path array to string.
*
* @type {(path: XastElement, data: Array<PathDataItem>, params: Js2PathParams) => void}
*/
exports.js2path = function (path, data, params) {
// @ts-ignore legacy
path.pathJS = data;
const pathData = [];
for (const item of data) {
// remove moveto commands which are followed by moveto commands
if (
pathData.length !== 0 &&
(item.command === 'M' || item.command === 'm')
) {
const last = pathData[pathData.length - 1];
if (last.command === 'M' || last.command === 'm') {
pathData.pop();
}
}
pathData.push({
command: item.command,
args: item.args,
});
}
path.attributes.d = stringifyPathData({
pathData,
precision: params.floatPrecision,
disableSpaceAfterFlags: params.noSpaceAfterFlags,
});
};
/**
* @type {(dest: Array<number>, source: Array<number>) => Array<number>}
*/
function set(dest, source) {
dest[0] = source[source.length - 2];
dest[1] = source[source.length - 1];
return dest;
}
/**
* Checks if two paths have an intersection by checking convex hulls
* collision using Gilbert-Johnson-Keerthi distance algorithm
* https://web.archive.org/web/20180822200027/http://entropyinteractive.com/2011/04/gjk-algorithm/
*
* @type {(path1: Array<PathDataItem>, path2: Array<PathDataItem>) => boolean}
*/
exports.intersects = function (path1, path2) {
// Collect points of every subpath.
const points1 = gatherPoints(convertRelativeToAbsolute(path1));
const points2 = gatherPoints(convertRelativeToAbsolute(path2));
// Axis-aligned bounding box check.
if (
points1.maxX <= points2.minX ||
points2.maxX <= points1.minX ||
points1.maxY <= points2.minY ||
points2.maxY <= points1.minY ||
points1.list.every((set1) => {
return points2.list.every((set2) => {
return (
set1.list[set1.maxX][0] <= set2.list[set2.minX][0] ||
set2.list[set2.maxX][0] <= set1.list[set1.minX][0] ||
set1.list[set1.maxY][1] <= set2.list[set2.minY][1] ||
set2.list[set2.maxY][1] <= set1.list[set1.minY][1]
);
});
})
)
return false;
// Get a convex hull from points of each subpath. Has the most complexity O(n·log n).
const hullNest1 = points1.list.map(convexHull);
const hullNest2 = points2.list.map(convexHull);
// Check intersection of every subpath of the first path with every subpath of the second.
return hullNest1.some(function (hull1) {
if (hull1.list.length < 3) return false;
return hullNest2.some(function (hull2) {
if (hull2.list.length < 3) return false;
var simplex = [getSupport(hull1, hull2, [1, 0])], // create the initial simplex
direction = minus(simplex[0]); // set the direction to point towards the origin
var iterations = 1e4; // infinite loop protection, 10 000 iterations is more than enough
// eslint-disable-next-line no-constant-condition
while (true) {
// eslint-disable-next-line no-constant-condition
if (iterations-- == 0) {
console.error(
'Error: infinite loop while processing mergePaths plugin.'
);
return true; // true is the safe value that means “do nothing with paths”
}
// add a new point
simplex.push(getSupport(hull1, hull2, direction));
// see if the new point was on the correct side of the origin
if (dot(direction, simplex[simplex.length - 1]) <= 0) return false;
// process the simplex
if (processSimplex(simplex, direction)) return true;
}
});
});
/**
* @type {(a: Point, b: Point, direction: Array<number>) => Array<number>}
*/
function getSupport(a, b, direction) {
return sub(supportPoint(a, direction), supportPoint(b, minus(direction)));
}
// Computes farthest polygon point in particular direction.
// Thanks to knowledge of min/max x and y coordinates we can choose a quadrant to search in.
// Since we're working on convex hull, the dot product is increasing until we find the farthest point.
/**
* @type {(polygon: Point, direction: Array<number>) => Array<number>}
*/
function supportPoint(polygon, direction) {
var index =
direction[1] >= 0
? direction[0] < 0
? polygon.maxY
: polygon.maxX
: direction[0] < 0
? polygon.minX
: polygon.minY,
max = -Infinity,
value;
while ((value = dot(polygon.list[index], direction)) > max) {
max = value;
index = ++index % polygon.list.length;
}
return polygon.list[(index || polygon.list.length) - 1];
}
};
/**
* @type {(simplex: Array<Array<number>>, direction: Array<number>) => boolean}
*/
function processSimplex(simplex, direction) {
// we only need to handle to 1-simplex and 2-simplex
if (simplex.length == 2) {
// 1-simplex
let a = simplex[1],
b = simplex[0],
AO = minus(simplex[1]),
AB = sub(b, a);
// AO is in the same direction as AB
if (dot(AO, AB) > 0) {
// get the vector perpendicular to AB facing O
set(direction, orth(AB, a));
} else {
set(direction, AO);
// only A remains in the simplex
simplex.shift();
}
} else {
// 2-simplex
let a = simplex[2], // [a, b, c] = simplex
b = simplex[1],
c = simplex[0],
AB = sub(b, a),
AC = sub(c, a),
AO = minus(a),
ACB = orth(AB, AC), // the vector perpendicular to AB facing away from C
ABC = orth(AC, AB); // the vector perpendicular to AC facing away from B
if (dot(ACB, AO) > 0) {
if (dot(AB, AO) > 0) {
// region 4
set(direction, ACB);
simplex.shift(); // simplex = [b, a]
} else {
// region 5
set(direction, AO);
simplex.splice(0, 2); // simplex = [a]
}
} else if (dot(ABC, AO) > 0) {
if (dot(AC, AO) > 0) {
// region 6
set(direction, ABC);
simplex.splice(1, 1); // simplex = [c, a]
} else {
// region 5 (again)
set(direction, AO);
simplex.splice(0, 2); // simplex = [a]
}
} // region 7
else return true;
}
return false;
}
/**
* @type {(v: Array<number>) => Array<number>}
*/
function minus(v) {
return [-v[0], -v[1]];
}
/**
* @type {(v1: Array<number>, v2: Array<number>) => Array<number>}
*/
function sub(v1, v2) {
return [v1[0] - v2[0], v1[1] - v2[1]];
}
/**
* @type {(v1: Array<number>, v2: Array<number>) => number}
*/
function dot(v1, v2) {
return v1[0] * v2[0] + v1[1] * v2[1];
}
/**
* @type {(v1: Array<number>, v2: Array<number>) => Array<number>}
*/
function orth(v, from) {
var o = [-v[1], v[0]];
return dot(o, minus(from)) < 0 ? minus(o) : o;
}
/**
* @typedef {{
* list: Array<Array<number>>,
* minX: number,
* minY: number,
* maxX: number,
* maxY: number
* }} Point
*/
/**
* @typedef {{
* list: Array<Point>,
* minX: number,
* minY: number,
* maxX: number,
* maxY: number
* }} Points
*/
/**
* @type {(pathData: Array<PathDataItem>) => Points}
*/
function gatherPoints(pathData) {
/**
* @type {Points}
*/
const points = { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 };
// Writes data about the extreme points on each axle
/**
* @type {(path: Point, point: Array<number>) => void}
*/
const addPoint = (path, point) => {
if (!path.list.length || point[1] > path.list[path.maxY][1]) {
path.maxY = path.list.length;
points.maxY = points.list.length
? Math.max(point[1], points.maxY)
: point[1];
}
if (!path.list.length || point[0] > path.list[path.maxX][0]) {
path.maxX = path.list.length;
points.maxX = points.list.length
? Math.max(point[0], points.maxX)
: point[0];
}
if (!path.list.length || point[1] < path.list[path.minY][1]) {
path.minY = path.list.length;
points.minY = points.list.length
? Math.min(point[1], points.minY)
: point[1];
}
if (!path.list.length || point[0] < path.list[path.minX][0]) {
path.minX = path.list.length;
points.minX = points.list.length
? Math.min(point[0], points.minX)
: point[0];
}
path.list.push(point);
};
for (let i = 0; i < pathData.length; i += 1) {
const pathDataItem = pathData[i];
let subPath =
points.list.length === 0
? { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 }
: points.list[points.list.length - 1];
let prev = i === 0 ? null : pathData[i - 1];
let basePoint =
subPath.list.length === 0 ? null : subPath.list[subPath.list.length - 1];
let data = pathDataItem.args;
let ctrlPoint = basePoint;
/**
* @type {(n: number, i: number) => number}
* TODO fix null hack
*/
const toAbsolute = (n, i) => n + (basePoint == null ? 0 : basePoint[i % 2]);
switch (pathDataItem.command) {
case 'M':
subPath = { list: [], minX: 0, minY: 0, maxX: 0, maxY: 0 };
points.list.push(subPath);
break;
case 'H':
if (basePoint != null) {
addPoint(subPath, [data[0], basePoint[1]]);
}
break;
case 'V':
if (basePoint != null) {
addPoint(subPath, [basePoint[0], data[0]]);
}
break;
case 'Q':
addPoint(subPath, data.slice(0, 2));
prevCtrlPoint = [data[2] - data[0], data[3] - data[1]]; // Save control point for shorthand
break;
case 'T':
if (
basePoint != null &&
prev != null &&
(prev.command == 'Q' || prev.command == 'T')
) {
ctrlPoint = [
basePoint[0] + prevCtrlPoint[0],
basePoint[1] + prevCtrlPoint[1],
];
addPoint(subPath, ctrlPoint);
prevCtrlPoint = [data[0] - ctrlPoint[0], data[1] - ctrlPoint[1]];
}
break;
case 'C':
if (basePoint != null) {
// Approximate quibic Bezier curve with middle points between control points
addPoint(subPath, [
0.5 * (basePoint[0] + data[0]),
0.5 * (basePoint[1] + data[1]),
]);
}
addPoint(subPath, [
0.5 * (data[0] + data[2]),
0.5 * (data[1] + data[3]),
]);
addPoint(subPath, [
0.5 * (data[2] + data[4]),
0.5 * (data[3] + data[5]),
]);
prevCtrlPoint = [data[4] - data[2], data[5] - data[3]]; // Save control point for shorthand
break;
case 'S':
if (
basePoint != null &&
prev != null &&
(prev.command == 'C' || prev.command == 'S')
) {
addPoint(subPath, [
basePoint[0] + 0.5 * prevCtrlPoint[0],
basePoint[1] + 0.5 * prevCtrlPoint[1],
]);
ctrlPoint = [
basePoint[0] + prevCtrlPoint[0],
basePoint[1] + prevCtrlPoint[1],
];
}
if (ctrlPoint != null) {
addPoint(subPath, [
0.5 * (ctrlPoint[0] + data[0]),
0.5 * (ctrlPoint[1] + data[1]),
]);
}
addPoint(subPath, [
0.5 * (data[0] + data[2]),
0.5 * (data[1] + data[3]),
]);
prevCtrlPoint = [data[2] - data[0], data[3] - data[1]];
break;
case 'A':
if (basePoint != null) {
// Convert the arc to bezier curves and use the same approximation
// @ts-ignore no idea what's going on here
var curves = a2c.apply(0, basePoint.concat(data));
for (
var cData;
(cData = curves.splice(0, 6).map(toAbsolute)).length;
) {
if (basePoint != null) {
addPoint(subPath, [
0.5 * (basePoint[0] + cData[0]),
0.5 * (basePoint[1] + cData[1]),
]);
}
addPoint(subPath, [
0.5 * (cData[0] + cData[2]),
0.5 * (cData[1] + cData[3]),
]);
addPoint(subPath, [
0.5 * (cData[2] + cData[4]),
0.5 * (cData[3] + cData[5]),
]);
if (curves.length) addPoint(subPath, (basePoint = cData.slice(-2)));
}
}
break;
}
// Save final command coordinates
if (data.length >= 2) addPoint(subPath, data.slice(-2));
}
return points;
}
/**
* Forms a convex hull from set of points of every subpath using monotone chain convex hull algorithm.
* https://en.wikibooks.org/wiki/Algorithm_Implementation/Geometry/Convex_hull/Monotone_chain
*
* @type {(points: Point) => Point}
*/
function convexHull(points) {
points.list.sort(function (a, b) {
return a[0] == b[0] ? a[1] - b[1] : a[0] - b[0];
});
var lower = [],
minY = 0,
bottom = 0;
for (let i = 0; i < points.list.length; i++) {
while (
lower.length >= 2 &&
cross(lower[lower.length - 2], lower[lower.length - 1], points.list[i]) <=
0
) {
lower.pop();
}
if (points.list[i][1] < points.list[minY][1]) {
minY = i;
bottom = lower.length;
}
lower.push(points.list[i]);
}
var upper = [],
maxY = points.list.length - 1,
top = 0;
for (let i = points.list.length; i--; ) {
while (
upper.length >= 2 &&
cross(upper[upper.length - 2], upper[upper.length - 1], points.list[i]) <=
0
) {
upper.pop();
}
if (points.list[i][1] > points.list[maxY][1]) {
maxY = i;
top = upper.length;
}
upper.push(points.list[i]);
}
// last points are equal to starting points of the other part
upper.pop();
lower.pop();
const hullList = lower.concat(upper);
/**
* @type {Point}
*/
const hull = {
list: hullList,
minX: 0, // by sorting
maxX: lower.length,
minY: bottom,
maxY: (lower.length + top) % hullList.length,
};
return hull;
}
/**
* @type {(o: Array<number>, a: Array<number>, b: Array<number>) => number}
*/
function cross(o, a, b) {
return (a[0] - o[0]) * (b[1] - o[1]) - (a[1] - o[1]) * (b[0] - o[0]);
}
/**
* Based on code from Snap.svg (Apache 2 license). http://snapsvg.io/
* Thanks to Dmitry Baranovskiy for his great work!
*
* @type {(
* x1: number,
* y1: number,
* rx: number,
* ry: number,
* angle: number,
* large_arc_flag: number,
* sweep_flag: number,
* x2: number,
* y2: number,
* recursive: Array<number>
* ) => Array<number>}
*/
const a2c = (
x1,
y1,
rx,
ry,
angle,
large_arc_flag,
sweep_flag,
x2,
y2,
recursive
) => {
// for more information of where this Math came from visit:
// https://www.w3.org/TR/SVG11/implnote.html#ArcImplementationNotes
const _120 = (Math.PI * 120) / 180;
const rad = (Math.PI / 180) * (+angle || 0);
/**
* @type {Array<number>}
*/
let res = [];
/**
* @type {(x: number, y: number, rad: number) => number}
*/
const rotateX = (x, y, rad) => {
return x * Math.cos(rad) - y * Math.sin(rad);
};
/**
* @type {(x: number, y: number, rad: number) => number}
*/
const rotateY = (x, y, rad) => {
return x * Math.sin(rad) + y * Math.cos(rad);
};
if (!recursive) {
x1 = rotateX(x1, y1, -rad);
y1 = rotateY(x1, y1, -rad);
x2 = rotateX(x2, y2, -rad);
y2 = rotateY(x2, y2, -rad);
var x = (x1 - x2) / 2,
y = (y1 - y2) / 2;
var h = (x * x) / (rx * rx) + (y * y) / (ry * ry);
if (h > 1) {
h = Math.sqrt(h);
rx = h * rx;
ry = h * ry;
}
var rx2 = rx * rx;
var ry2 = ry * ry;
var k =
(large_arc_flag == sweep_flag ? -1 : 1) *
Math.sqrt(
Math.abs(
(rx2 * ry2 - rx2 * y * y - ry2 * x * x) / (rx2 * y * y + ry2 * x * x)
)
);
var cx = (k * rx * y) / ry + (x1 + x2) / 2;
var cy = (k * -ry * x) / rx + (y1 + y2) / 2;
var f1 = Math.asin(Number(((y1 - cy) / ry).toFixed(9)));
var f2 = Math.asin(Number(((y2 - cy) / ry).toFixed(9)));
f1 = x1 < cx ? Math.PI - f1 : f1;
f2 = x2 < cx ? Math.PI - f2 : f2;
f1 < 0 && (f1 = Math.PI * 2 + f1);
f2 < 0 && (f2 = Math.PI * 2 + f2);
if (sweep_flag && f1 > f2) {
f1 = f1 - Math.PI * 2;
}
if (!sweep_flag && f2 > f1) {
f2 = f2 - Math.PI * 2;
}
} else {
f1 = recursive[0];
f2 = recursive[1];
cx = recursive[2];
cy = recursive[3];
}
var df = f2 - f1;
if (Math.abs(df) > _120) {
var f2old = f2,
x2old = x2,
y2old = y2;
f2 = f1 + _120 * (sweep_flag && f2 > f1 ? 1 : -1);
x2 = cx + rx * Math.cos(f2);
y2 = cy + ry * Math.sin(f2);
res = a2c(x2, y2, rx, ry, angle, 0, sweep_flag, x2old, y2old, [
f2,
f2old,
cx,
cy,
]);
}
df = f2 - f1;
var c1 = Math.cos(f1),
s1 = Math.sin(f1),
c2 = Math.cos(f2),
s2 = Math.sin(f2),
t = Math.tan(df / 4),
hx = (4 / 3) * rx * t,
hy = (4 / 3) * ry * t,
m = [
-hx * s1,
hy * c1,
x2 + hx * s2 - x1,
y2 - hy * c2 - y1,
x2 - x1,
y2 - y1,
];
if (recursive) {
return m.concat(res);
} else {
res = m.concat(res);
var newres = [];
for (var i = 0, n = res.length; i < n; i++) {
newres[i] =
i % 2
? rotateY(res[i - 1], res[i], rad)
: rotateX(res[i], res[i + 1], rad);
}
return newres;
}
};