| |
| let cacheDigits, cacheAppend, cacheRadius, cacheCircle; |
|
|
| export default class PathString { |
| constructor(digits) { |
| this._append = digits == null ? append : appendRound(digits); |
| this._radius = 4.5; |
| this._ = ""; |
| } |
| pointRadius(_) { |
| this._radius = +_; |
| return this; |
| } |
| polygonStart() { |
| this._line = 0; |
| } |
| polygonEnd() { |
| this._line = NaN; |
| } |
| lineStart() { |
| this._point = 0; |
| } |
| lineEnd() { |
| if (this._line === 0) this._ += "Z"; |
| this._point = NaN; |
| } |
| point(x, y) { |
| switch (this._point) { |
| case 0: { |
| this._append`M${x},${y}`; |
| this._point = 1; |
| break; |
| } |
| case 1: { |
| this._append`L${x},${y}`; |
| break; |
| } |
| default: { |
| this._append`M${x},${y}`; |
| if (this._radius !== cacheRadius || this._append !== cacheAppend) { |
| const r = this._radius; |
| const s = this._; |
| this._ = ""; |
| this._append`m0,${r}a${r},${r} 0 1,1 0,${-2 * r}a${r},${r} 0 1,1 0,${2 * r}z`; |
| cacheRadius = r; |
| cacheAppend = this._append; |
| cacheCircle = this._; |
| this._ = s; |
| } |
| this._ += cacheCircle; |
| break; |
| } |
| } |
| } |
| result() { |
| const result = this._; |
| this._ = ""; |
| return result.length ? result : null; |
| } |
| } |
|
|
| function append(strings) { |
| let i = 1; |
| this._ += strings[0]; |
| for (const j = strings.length; i < j; ++i) { |
| this._ += arguments[i] + strings[i]; |
| } |
| } |
|
|
| function appendRound(digits) { |
| const d = Math.floor(digits); |
| if (!(d >= 0)) throw new RangeError(`invalid digits: ${digits}`); |
| if (d > 15) return append; |
| if (d !== cacheDigits) { |
| const k = 10 ** d; |
| cacheDigits = d; |
| cacheAppend = function append(strings) { |
| let i = 1; |
| this._ += strings[0]; |
| for (const j = strings.length; i < j; ++i) { |
| this._ += Math.round(arguments[i] * k) / k + strings[i]; |
| } |
| }; |
| } |
| return cacheAppend; |
| } |
|
|
