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1const pi = Math.PI, tau = 2 * pi, epsilon = 1e-6, tauEpsilon = tau - epsilon;
2function append(strings) {
3 this._ += strings[0];
4 for (let i = 1, n = strings.length; i < n; ++i) {
5 this._ += arguments[i] + strings[i];
6 }
7}
8function appendRound(digits) {
9 let d = Math.floor(digits);
10 if (!(d >= 0))
11 throw new Error(`invalid digits: ${digits}`);
12 if (d > 15)
13 return append;
14 const k = 10 ** d;
15 return function(strings) {
16 this._ += strings[0];
17 for (let i = 1, n = strings.length; i < n; ++i) {
18 this._ += Math.round(arguments[i] * k) / k + strings[i];
19 }
20 };
21}
22class Path {
23 constructor(digits) {
24 this._x0 = this._y0 = // start of current subpath
25 this._x1 = this._y1 = null;
26 this._ = "";
27 this._append = digits == null ? append : appendRound(digits);
28 }
29 moveTo(x, y) {
30 this._append`M${this._x0 = this._x1 = +x},${this._y0 = this._y1 = +y}`;
31 }
32 closePath() {
33 if (this._x1 !== null) {
34 this._x1 = this._x0, this._y1 = this._y0;
35 this._append`Z`;
36 }
37 }
38 lineTo(x, y) {
39 this._append`L${this._x1 = +x},${this._y1 = +y}`;
40 }
41 quadraticCurveTo(x1, y1, x, y) {
42 this._append`Q${+x1},${+y1},${this._x1 = +x},${this._y1 = +y}`;
43 }
44 bezierCurveTo(x1, y1, x2, y2, x, y) {
45 this._append`C${+x1},${+y1},${+x2},${+y2},${this._x1 = +x},${this._y1 = +y}`;
46 }
47 arcTo(x1, y1, x2, y2, r) {
48 x1 = +x1, y1 = +y1, x2 = +x2, y2 = +y2, r = +r;
49 if (r < 0)
50 throw new Error(`negative radius: ${r}`);
51 let x0 = this._x1, y0 = this._y1, x21 = x2 - x1, y21 = y2 - y1, x01 = x0 - x1, y01 = y0 - y1, l01_2 = x01 * x01 + y01 * y01;
52 if (this._x1 === null) {
53 this._append`M${this._x1 = x1},${this._y1 = y1}`;
54 } else if (!(l01_2 > epsilon))
55 ;
56 else if (!(Math.abs(y01 * x21 - y21 * x01) > epsilon) || !r) {
57 this._append`L${this._x1 = x1},${this._y1 = y1}`;
58 } else {
59 let x20 = x2 - x0, y20 = y2 - y0, l21_2 = x21 * x21 + y21 * y21, l20_2 = x20 * x20 + y20 * y20, l21 = Math.sqrt(l21_2), l01 = Math.sqrt(l01_2), l = r * Math.tan((pi - Math.acos((l21_2 + l01_2 - l20_2) / (2 * l21 * l01))) / 2), t01 = l / l01, t21 = l / l21;
60 if (Math.abs(t01 - 1) > epsilon) {
61 this._append`L${x1 + t01 * x01},${y1 + t01 * y01}`;
62 }
63 this._append`A${r},${r},0,0,${+(y01 * x20 > x01 * y20)},${this._x1 = x1 + t21 * x21},${this._y1 = y1 + t21 * y21}`;
64 }
65 }
66 arc(x, y, r, a0, a1, ccw) {
67 x = +x, y = +y, r = +r, ccw = !!ccw;
68 if (r < 0)
69 throw new Error(`negative radius: ${r}`);
70 let dx = r * Math.cos(a0), dy = r * Math.sin(a0), x0 = x + dx, y0 = y + dy, cw = 1 ^ ccw, da = ccw ? a0 - a1 : a1 - a0;
71 if (this._x1 === null) {
72 this._append`M${x0},${y0}`;
73 } else if (Math.abs(this._x1 - x0) > epsilon || Math.abs(this._y1 - y0) > epsilon) {
74 this._append`L${x0},${y0}`;
75 }
76 if (!r)
77 return;
78 if (da < 0)
79 da = da % tau + tau;
80 if (da > tauEpsilon) {
81 this._append`A${r},${r},0,1,${cw},${x - dx},${y - dy}A${r},${r},0,1,${cw},${this._x1 = x0},${this._y1 = y0}`;
82 } else if (da > epsilon) {
83 this._append`A${r},${r},0,${+(da >= pi)},${cw},${this._x1 = x + r * Math.cos(a1)},${this._y1 = y + r * Math.sin(a1)}`;
84 }
85 }
86 rect(x, y, w, h) {
87 this._append`M${this._x0 = this._x1 = +x},${this._y0 = this._y1 = +y}h${w = +w}v${+h}h${-w}Z`;
88 }
89 toString() {
90 return this._;
91 }
92}
93function constant(x) {
94 return function constant2() {
95 return x;
96 };
97}
98function withPath(shape) {
99 let digits = 3;
100 shape.digits = function(_) {
101 if (!arguments.length)
102 return digits;
103 if (_ == null) {
104 digits = null;
105 } else {
106 const d = Math.floor(_);
107 if (!(d >= 0))
108 throw new RangeError(`invalid digits: ${_}`);
109 digits = d;
110 }
111 return shape;
112 };
113 return () => new Path(digits);
114}
115export {
116 constant as c,
117 withPath as w
118};