import {epsilon} from "../math.js"; import {Cardinal} from "./cardinal.js"; export function point(that, x, y) { var x1 = that._x1, y1 = that._y1, x2 = that._x2, y2 = that._y2; if (that._l01_a > epsilon) { var a = 2 * that._l01_2a + 3 * that._l01_a * that._l12_a + that._l12_2a, n = 3 * that._l01_a * (that._l01_a + that._l12_a); x1 = (x1 * a - that._x0 * that._l12_2a + that._x2 * that._l01_2a) / n; y1 = (y1 * a - that._y0 * that._l12_2a + that._y2 * that._l01_2a) / n; } if (that._l23_a > epsilon) { var b = 2 * that._l23_2a + 3 * that._l23_a * that._l12_a + that._l12_2a, m = 3 * that._l23_a * (that._l23_a + that._l12_a); x2 = (x2 * b + that._x1 * that._l23_2a - x * that._l12_2a) / m; y2 = (y2 * b + that._y1 * that._l23_2a - y * that._l12_2a) / m; } that._context.bezierCurveTo(x1, y1, x2, y2, that._x2, that._y2); } function CatmullRom(context, alpha) { this._context = context; this._alpha = alpha; } CatmullRom.prototype = { areaStart: function() { this._line = 0; }, areaEnd: function() { this._line = NaN; }, lineStart: function() { this._x0 = this._x1 = this._x2 = this._y0 = this._y1 = this._y2 = NaN; this._l01_a = this._l12_a = this._l23_a = this._l01_2a = this._l12_2a = this._l23_2a = this._point = 0; }, lineEnd: function() { switch (this._point) { case 2: this._context.lineTo(this._x2, this._y2); break; case 3: this.point(this._x2, this._y2); break; } if (this._line || (this._line !== 0 && this._point === 1)) this._context.closePath(); this._line = 1 - this._line; }, point: function(x, y) { x = +x, y = +y; if (this._point) { var x23 = this._x2 - x, y23 = this._y2 - y; this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha)); } switch (this._point) { case 0: this._point = 1; this._line ? this._context.lineTo(x, y) : this._context.moveTo(x, y); break; case 1: this._point = 2; break; case 2: this._point = 3; // proceed default: point(this, x, y); break; } this._l01_a = this._l12_a, this._l12_a = this._l23_a; this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a; this._x0 = this._x1, this._x1 = this._x2, this._x2 = x; this._y0 = this._y1, this._y1 = this._y2, this._y2 = y; } }; export default (function custom(alpha) { function catmullRom(context) { return alpha ? new CatmullRom(context, alpha) : new Cardinal(context, 0); } catmullRom.alpha = function(alpha) { return custom(+alpha); }; return catmullRom; })(0.5);