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Fix LOS clearance: use real bezier apex, not control point

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Graham McIntire 2026-04-22 16:18:12 -05:00
parent ae6d50f1a9
commit b8380e3e0f
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1 changed files with 5 additions and 4 deletions
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static/js/nlos.js
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@ -279,12 +279,13 @@
const h2px = s.values.h2 * pxPerM;
const yA = groundY - h1px, yB = groundY - h2px;
// signal line, compute clearance over hill apex
// signal line, compute clearance over the hill's actual apex. The hill is drawn
// as a quadratic bezier from (hx-hw, groundY) to (hx+hw, groundY) with control
// at (hx, groundY - hh*2). At t=0.5 the curve reaches groundY - hh, which is
// the real visual top. Using the control-point y here would over-count by 2x.
const t = (hx - xA) / (xB - xA);
const yOnRay = yA + (yB - yA) * t;
const hillTop = groundY - hh * 2;
const clearance = hillTop - yOnRay; // negative = obstructed... actually no: smaller y = higher. yOnRay < hillTop (more negative offset) means ray is ABOVE hill => clearance positive.
// With screen coords (y down), ray above hill means yOnRay < hillTop. Clearance in meters = (hillTop - yOnRay)/pxPerM. Positive when ray above hill.
const hillTop = groundY - hh;
const clearanceM = (hillTop - yOnRay) / pxPerM;
const blocked = clearanceM < 0;