@antv/x6
Version:
JavaScript diagramming library that uses SVG and HTML for rendering
387 lines • 12.8 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Line = void 0;
const point_1 = require("./point");
const geometry_1 = require("./geometry");
const rectangle_1 = require("./rectangle");
class Line extends geometry_1.Geometry {
static isLine(instance) {
return instance != null && instance instanceof Line;
}
get center() {
return new point_1.Point((this.start.x + this.end.x) / 2, (this.start.y + this.end.y) / 2);
}
constructor(x1, y1, x2, y2) {
super();
if (typeof x1 === 'number' && typeof y1 === 'number') {
this.start = new point_1.Point(x1, y1);
this.end = new point_1.Point(x2, y2);
}
else {
this.start = point_1.Point.create(x1);
this.end = point_1.Point.create(y1);
}
}
getCenter() {
return this.center;
}
/**
* Rounds the line to the given `precision`.
*/
round(precision = 0) {
this.start.round(precision);
this.end.round(precision);
return this;
}
translate(tx, ty) {
if (typeof tx === 'number') {
this.start.translate(tx, ty);
this.end.translate(tx, ty);
}
else {
this.start.translate(tx);
this.end.translate(tx);
}
return this;
}
/**
* Rotate the line by `angle` around `origin`.
*/
rotate(angle, origin) {
this.start.rotate(angle, origin);
this.end.rotate(angle, origin);
return this;
}
/**
* Scale the line by `sx` and `sy` about the given `origin`. If origin is not
* specified, the line is scaled around `0,0`.
*/
scale(sx, sy, origin) {
this.start.scale(sx, sy, origin);
this.end.scale(sx, sy, origin);
return this;
}
/**
* Returns the length of the line.
*/
length() {
return Math.sqrt(this.squaredLength());
}
/**
* Useful for distance comparisons in which real length is not necessary
* (saves one `Math.sqrt()` operation).
*/
squaredLength() {
const dx = this.start.x - this.end.x;
const dy = this.start.y - this.end.y;
return dx * dx + dy * dy;
}
/**
* Scale the line so that it has the requested length. The start point of
* the line is preserved.
*/
setLength(length) {
const total = this.length();
if (!total) {
return this;
}
const scale = length / total;
return this.scale(scale, scale, this.start);
}
parallel(distance) {
const line = this.clone();
if (!line.isDifferentiable()) {
return line;
}
const { start, end } = line;
const eRef = start.clone().rotate(270, end);
const sRef = end.clone().rotate(90, start);
start.move(sRef, distance);
end.move(eRef, distance);
return line;
}
/**
* Returns the vector of the line with length equal to length of the line.
*/
vector() {
return new point_1.Point(this.end.x - this.start.x, this.end.y - this.start.y);
}
/**
* Returns the angle of incline of the line.
*
* The function returns `NaN` if the start and end endpoints of the line
* both lie at the same coordinates(it is impossible to determine the angle
* of incline of a line that appears to be a point). The
* `line.isDifferentiable()` function may be used in advance to determine
* whether the angle of incline can be computed for a given line.
*/
angle() {
const ref = new point_1.Point(this.start.x + 1, this.start.y);
return this.start.angleBetween(this.end, ref);
}
/**
* Returns a rectangle that is the bounding box of the line.
*/
bbox() {
const left = Math.min(this.start.x, this.end.x);
const top = Math.min(this.start.y, this.end.y);
const right = Math.max(this.start.x, this.end.x);
const bottom = Math.max(this.start.y, this.end.y);
return new rectangle_1.Rectangle(left, top, right - left, bottom - top);
}
/**
* Returns the bearing (cardinal direction) of the line.
*
* The return value is one of the following strings:
* 'NE', 'E', 'SE', 'S', 'SW', 'W', 'NW' and 'N'.
*
* The function returns 'N' if the two endpoints of the line are coincident.
*/
bearing() {
return this.start.bearing(this.end);
}
/**
* Returns the point on the line that lies closest to point `p`.
*/
closestPoint(p) {
return this.pointAt(this.closestPointNormalizedLength(p));
}
/**
* Returns the length of the line up to the point that lies closest to point `p`.
*/
closestPointLength(p) {
return this.closestPointNormalizedLength(p) * this.length();
}
/**
* Returns a line that is tangent to the line at the point that lies closest
* to point `p`.
*/
closestPointTangent(p) {
return this.tangentAt(this.closestPointNormalizedLength(p));
}
/**
* Returns the normalized length (distance from the start of the line / total
* line length) of the line up to the point that lies closest to point.
*/
closestPointNormalizedLength(p) {
const product = this.vector().dot(new Line(this.start, p).vector());
const normalized = Math.min(1, Math.max(0, product / this.squaredLength()));
// normalized returns `NaN` if this line has zero length
if (Number.isNaN(normalized)) {
return 0;
}
return normalized;
}
/**
* Returns a point on the line that lies `rate` (normalized length) away from
* the beginning of the line.
*/
pointAt(ratio) {
const start = this.start;
const end = this.end;
if (ratio <= 0) {
return start.clone();
}
if (ratio >= 1) {
return end.clone();
}
return start.lerp(end, ratio);
}
/**
* Returns a point on the line that lies length away from the beginning of
* the line.
*/
pointAtLength(length) {
const start = this.start;
const end = this.end;
let fromStart = true;
if (length < 0) {
fromStart = false; // start calculation from end point
length = -length; // eslint-disable-line
}
const total = this.length();
if (length >= total) {
return fromStart ? end.clone() : start.clone();
}
const rate = (fromStart ? length : total - length) / total;
return this.pointAt(rate);
}
/**
* Divides the line into two lines at the point that lies `rate` (normalized
* length) away from the beginning of the line.
*/
divideAt(ratio) {
const dividerPoint = this.pointAt(ratio);
return [
new Line(this.start, dividerPoint),
new Line(dividerPoint, this.end),
];
}
/**
* Divides the line into two lines at the point that lies length away from
* the beginning of the line.
*/
divideAtLength(length) {
const dividerPoint = this.pointAtLength(length);
return [
new Line(this.start, dividerPoint),
new Line(dividerPoint, this.end),
];
}
/**
* Returns `true` if the point `p` lies on the line. Return `false` otherwise.
*/
containsPoint(p) {
const start = this.start;
const end = this.end;
// cross product of 0 indicates that this line and
// the vector to `p` are collinear.
if (start.cross(p, end) !== 0) {
return false;
}
const length = this.length();
if (new Line(start, p).length() > length) {
return false;
}
if (new Line(p, end).length() > length) {
return false;
}
return true;
}
intersect(shape, options) {
const ret = shape.intersectsWithLine(this, options);
if (ret) {
return Array.isArray(ret) ? ret : [ret];
}
return null;
}
/**
* Returns the intersection point of the line with another line. Returns
* `null` if no intersection exists.
*/
intersectsWithLine(line) {
const pt1Dir = new point_1.Point(this.end.x - this.start.x, this.end.y - this.start.y);
const pt2Dir = new point_1.Point(line.end.x - line.start.x, line.end.y - line.start.y);
const det = pt1Dir.x * pt2Dir.y - pt1Dir.y * pt2Dir.x;
const deltaPt = new point_1.Point(line.start.x - this.start.x, line.start.y - this.start.y);
const alpha = deltaPt.x * pt2Dir.y - deltaPt.y * pt2Dir.x;
const beta = deltaPt.x * pt1Dir.y - deltaPt.y * pt1Dir.x;
if (det === 0 || alpha * det < 0 || beta * det < 0) {
return null;
}
if (det > 0) {
if (alpha > det || beta > det) {
return null;
}
}
else if (alpha < det || beta < det) {
return null;
}
return new point_1.Point(this.start.x + (alpha * pt1Dir.x) / det, this.start.y + (alpha * pt1Dir.y) / det);
}
/**
* Returns `true` if a tangent line can be found for the line.
*
* Tangents cannot be found if both of the line endpoints are coincident
* (the line appears to be a point).
*/
isDifferentiable() {
return !this.start.equals(this.end);
}
/**
* Returns the perpendicular distance between the line and point. The
* distance is positive if the point lies to the right of the line, negative
* if the point lies to the left of the line, and `0` if the point lies on
* the line.
*/
pointOffset(p) {
const ref = point_1.Point.clone(p);
const start = this.start;
const end = this.end;
const determinant = (end.x - start.x) * (ref.y - start.y) -
(end.y - start.y) * (ref.x - start.x);
return determinant / this.length();
}
pointSquaredDistance(x, y) {
const p = point_1.Point.create(x, y);
return this.closestPoint(p).squaredDistance(p);
}
pointDistance(x, y) {
const p = point_1.Point.create(x, y);
return this.closestPoint(p).distance(p);
}
/**
* Returns a line tangent to the line at point that lies `rate` (normalized
* length) away from the beginning of the line.
*/
tangentAt(ratio) {
if (!this.isDifferentiable()) {
return null;
}
const start = this.start;
const end = this.end;
const tangentStart = this.pointAt(ratio);
const tangentLine = new Line(start, end);
tangentLine.translate(tangentStart.x - start.x, tangentStart.y - start.y);
return tangentLine;
}
/**
* Returns a line tangent to the line at point that lies `length` away from
* the beginning of the line.
*/
tangentAtLength(length) {
if (!this.isDifferentiable()) {
return null;
}
const start = this.start;
const end = this.end;
const tangentStart = this.pointAtLength(length);
const tangentLine = new Line(start, end);
tangentLine.translate(tangentStart.x - start.x, tangentStart.y - start.y);
return tangentLine;
}
relativeCcw(x, y) {
const ref = point_1.Point.create(x, y);
let dx1 = ref.x - this.start.x;
let dy1 = ref.y - this.start.y;
const dx2 = this.end.x - this.start.x;
const dy2 = this.end.y - this.start.y;
let ccw = dx1 * dy2 - dy1 * dx2;
if (ccw === 0) {
ccw = dx1 * dx2 + dy1 * dy2;
if (ccw > 0.0) {
dx1 -= dx2;
dy1 -= dy2;
ccw = dx1 * dx2 + dy1 * dy2;
if (ccw < 0.0) {
ccw = 0.0;
}
}
}
return ccw < 0.0 ? -1 : ccw > 0.0 ? 1 : 0;
}
/**
* Return `true` if the line equals the other line.
*/
equals(l) {
return (l != null &&
this.start.x === l.start.x &&
this.start.y === l.start.y &&
this.end.x === l.end.x &&
this.end.y === l.end.y);
}
/**
* Returns another line which is a clone of the line.
*/
clone() {
return new Line(this.start, this.end);
}
toJSON() {
return { start: this.start.toJSON(), end: this.end.toJSON() };
}
serialize() {
return [this.start.serialize(), this.end.serialize()].join(' ');
}
}
exports.Line = Line;
//# sourceMappingURL=line.js.map