50 lines
1.3 KiB
JavaScript
50 lines
1.3 KiB
JavaScript
import {point} from "./cardinal.js";
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export function CardinalOpen(context, tension) {
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this._context = context;
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this._k = (1 - tension) / 6;
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}
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CardinalOpen.prototype = {
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areaStart: function() {
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this._line = 0;
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},
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areaEnd: function() {
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this._line = NaN;
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},
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lineStart: function() {
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this._x0 = this._x1 = this._x2 =
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this._y0 = this._y1 = this._y2 = NaN;
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this._point = 0;
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},
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lineEnd: function() {
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if (this._line || (this._line !== 0 && this._point === 3)) this._context.closePath();
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this._line = 1 - this._line;
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},
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point: function(x, y) {
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x = +x, y = +y;
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switch (this._point) {
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case 0: this._point = 1; break;
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case 1: this._point = 2; break;
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case 2: this._point = 3; this._line ? this._context.lineTo(this._x2, this._y2) : this._context.moveTo(this._x2, this._y2); break;
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case 3: this._point = 4; // falls through
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default: point(this, x, y); break;
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}
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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(tension) {
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function cardinal(context) {
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return new CardinalOpen(context, tension);
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}
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cardinal.tension = function(tension) {
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return custom(+tension);
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};
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return cardinal;
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})(0);
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