import {path} from "d3-path";
import {slice} from "../array.js";
import constant from "../constant.js";
import {x as pointX, y as pointY} from "../point.js";
import pointRadial from "../pointRadial.js";
function linkSource(d) {
return d.source;
}
function linkTarget(d) {
return d.target;
}
function link(curve) {
var source = linkSource,
target = linkTarget,
x = pointX,
y = pointY,
context = null;
function link() {
var buffer, argv = slice.call(arguments), s = source.apply(this, argv), t = target.apply(this, argv);
if (!context) context = buffer = path();
curve(context, +x.apply(this, (argv[0] = s, argv)), +y.apply(this, argv), +x.apply(this, (argv[0] = t, argv)), +y.apply(this, argv));
if (buffer) return context = null, buffer + "" || null;
}
link.source = function(_) {
return arguments.length ? (source = _, link) : source;
};
link.target = function(_) {
return arguments.length ? (target = _, link) : target;
};
link.x = function(_) {
return arguments.length ? (x = typeof _ === "function" ? _ : constant(+_), link) : x;
};
link.y = function(_) {
return arguments.length ? (y = typeof _ === "function" ? _ : constant(+_), link) : y;
};
link.context = function(_) {
return arguments.length ? ((context = _ == null ? null : _), link) : context;
};
return link;
}
function curveHorizontal(context, x0, y0, x1, y1) {
context.moveTo(x0, y0);
context.bezierCurveTo(x0 = (x0 + x1) / 2, y0, x0, y1, x1, y1);
}
function curveVertical(context, x0, y0, x1, y1) {
context.moveTo(x0, y0);
context.bezierCurveTo(x0, y0 = (y0 + y1) / 2, x1, y0, x1, y1);
}
function curveRadial(context, x0, y0, x1, y1) {
var p0 = pointRadial(x0, y0),
p1 = pointRadial(x0, y0 = (y0 + y1) / 2),
p2 = pointRadial(x1, y0),
p3 = pointRadial(x1, y1);
context.moveTo(p0[0], p0[1]);
context.bezierCurveTo(p1[0], p1[1], p2[0], p2[1], p3[0], p3[1]);
}
export function linkHorizontal() {
return link(curveHorizontal);
}
export function linkVertical() {
return link(curveVertical);
}
export function linkRadial() {
var l = link(curveRadial);
l.angle = l.x, delete l.x;
l.radius = l.y, delete l.y;
return l;
}