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- export default function windingLine(x0, y0, x1, y1, x, y) {
- if ((y > y0 && y > y1) || (y < y0 && y < y1)) {
- return 0;
- }
- if (y1 === y0) {
- return 0;
- }
- var t = (y - y0) / (y1 - y0);
- var dir = y1 < y0 ? 1 : -1;
- if (t === 1 || t === 0) {
- dir = y1 < y0 ? 0.5 : -0.5;
- }
- var x_ = t * (x1 - x0) + x0;
- return x_ === x ? Infinity : x_ > x ? dir : 0;
- }
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