75 lines
2.0 KiB
JavaScript
75 lines
2.0 KiB
JavaScript
import {CardinalClosed} from "./cardinalClosed.js";
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import noop from "../noop.js";
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import {point} from "./catmullRom.js";
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function CatmullRomClosed(context, alpha) {
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this._context = context;
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this._alpha = alpha;
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}
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CatmullRomClosed.prototype = {
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areaStart: noop,
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areaEnd: noop,
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lineStart: function() {
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this._x0 = this._x1 = this._x2 = this._x3 = this._x4 = this._x5 =
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this._y0 = this._y1 = this._y2 = this._y3 = this._y4 = this._y5 = NaN;
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this._l01_a = this._l12_a = this._l23_a =
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this._l01_2a = this._l12_2a = this._l23_2a =
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this._point = 0;
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},
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lineEnd: function() {
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switch (this._point) {
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case 1: {
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this._context.moveTo(this._x3, this._y3);
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this._context.closePath();
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break;
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}
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case 2: {
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this._context.lineTo(this._x3, this._y3);
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this._context.closePath();
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break;
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}
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case 3: {
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this.point(this._x3, this._y3);
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this.point(this._x4, this._y4);
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this.point(this._x5, this._y5);
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break;
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}
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}
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},
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point: function(x, y) {
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x = +x, y = +y;
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if (this._point) {
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var x23 = this._x2 - x,
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y23 = this._y2 - y;
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this._l23_a = Math.sqrt(this._l23_2a = Math.pow(x23 * x23 + y23 * y23, this._alpha));
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}
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switch (this._point) {
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case 0: this._point = 1; this._x3 = x, this._y3 = y; break;
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case 1: this._point = 2; this._context.moveTo(this._x4 = x, this._y4 = y); break;
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case 2: this._point = 3; this._x5 = x, this._y5 = y; break;
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default: point(this, x, y); break;
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}
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this._l01_a = this._l12_a, this._l12_a = this._l23_a;
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this._l01_2a = this._l12_2a, this._l12_2a = this._l23_2a;
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this._x0 = this._x1, this._x1 = this._x2, this._x2 = x;
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this._y0 = this._y1, this._y1 = this._y2, this._y2 = y;
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}
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};
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export default (function custom(alpha) {
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function catmullRom(context) {
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return alpha ? new CatmullRomClosed(context, alpha) : new CardinalClosed(context, 0);
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}
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catmullRom.alpha = function(alpha) {
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return custom(+alpha);
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};
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return catmullRom;
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})(0.5);
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