60 lines
1.1 KiB
JavaScript
60 lines
1.1 KiB
JavaScript
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export default function(a, b, x0, y0, x1, y1) {
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var ax = a[0],
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ay = a[1],
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bx = b[0],
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by = b[1],
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t0 = 0,
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t1 = 1,
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dx = bx - ax,
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dy = by - ay,
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r;
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r = x0 - ax;
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if (!dx && r > 0) return;
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r /= dx;
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if (dx < 0) {
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if (r < t0) return;
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if (r < t1) t1 = r;
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} else if (dx > 0) {
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if (r > t1) return;
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if (r > t0) t0 = r;
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}
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r = x1 - ax;
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if (!dx && r < 0) return;
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r /= dx;
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if (dx < 0) {
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if (r > t1) return;
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if (r > t0) t0 = r;
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} else if (dx > 0) {
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if (r < t0) return;
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if (r < t1) t1 = r;
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}
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r = y0 - ay;
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if (!dy && r > 0) return;
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r /= dy;
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if (dy < 0) {
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if (r < t0) return;
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if (r < t1) t1 = r;
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} else if (dy > 0) {
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if (r > t1) return;
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if (r > t0) t0 = r;
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}
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r = y1 - ay;
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if (!dy && r < 0) return;
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r /= dy;
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if (dy < 0) {
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if (r > t1) return;
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if (r > t0) t0 = r;
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} else if (dy > 0) {
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if (r < t0) return;
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if (r < t1) t1 = r;
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}
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if (t0 > 0) a[0] = ax + t0 * dx, a[1] = ay + t0 * dy;
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if (t1 < 1) b[0] = ax + t1 * dx, b[1] = ay + t1 * dy;
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return true;
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}
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