48 lines
1.2 KiB
JavaScript
48 lines
1.2 KiB
JavaScript
'use strict';
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var buildArc = require('./buildArc.js');
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"use strict";
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function buildArcTo(points, x1, y1, x2, y2, radius) {
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const fromX = points[points.length - 2];
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const fromY = points[points.length - 1];
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const a1 = fromY - y1;
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const b1 = fromX - x1;
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const a2 = y2 - y1;
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const b2 = x2 - x1;
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const mm = Math.abs(a1 * b2 - b1 * a2);
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if (mm < 1e-8 || radius === 0) {
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if (points[points.length - 2] !== x1 || points[points.length - 1] !== y1) {
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points.push(x1, y1);
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}
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return;
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}
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const dd = a1 * a1 + b1 * b1;
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const cc = a2 * a2 + b2 * b2;
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const tt = a1 * a2 + b1 * b2;
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const k1 = radius * Math.sqrt(dd) / mm;
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const k2 = radius * Math.sqrt(cc) / mm;
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const j1 = k1 * tt / dd;
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const j2 = k2 * tt / cc;
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const cx = k1 * b2 + k2 * b1;
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const cy = k1 * a2 + k2 * a1;
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const px = b1 * (k2 + j1);
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const py = a1 * (k2 + j1);
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const qx = b2 * (k1 + j2);
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const qy = a2 * (k1 + j2);
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const startAngle = Math.atan2(py - cy, px - cx);
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const endAngle = Math.atan2(qy - cy, qx - cx);
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buildArc.buildArc(
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points,
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cx + x1,
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cy + y1,
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radius,
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startAngle,
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endAngle,
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b1 * a2 > b2 * a1
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);
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}
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exports.buildArcTo = buildArcTo;
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//# sourceMappingURL=buildArcTo.js.map
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