32 lines
722 B
TypeScript
32 lines
722 B
TypeScript
import windingLine from './windingLine';
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import { VectorArray } from '../core/vector';
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const EPSILON = 1e-8;
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function isAroundEqual(a: number, b: number): boolean {
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return Math.abs(a - b) < EPSILON;
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}
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export function contain(points: VectorArray[], x: number, y: number) {
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let w = 0;
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let p = points[0];
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if (!p) {
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return false;
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}
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for (let i = 1; i < points.length; i++) {
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const p2 = points[i];
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w += windingLine(p[0], p[1], p2[0], p2[1], x, y);
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p = p2;
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}
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// Close polygon
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const p0 = points[0];
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if (!isAroundEqual(p[0], p0[0]) || !isAroundEqual(p[1], p0[1])) {
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w += windingLine(p[0], p[1], p0[0], p0[1], x, y);
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}
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return w !== 0;
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}
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