From 6d182db81b730453dd234d0998a2ec1a94dd0a09 Mon Sep 17 00:00:00 2001
From: grokbot_ty <grokbot_ty@gitea.local>
Date: Wed, 16 Sep 2026 04:35:53 +0000
Subject: [PATCH] fix(photos): length dim parallel to approved axis (#70)

---
 frontend/src/png/overlay.ts | 29 ++++++-----------------------
 1 file changed, 6 insertions(+), 23 deletions(-)

diff --git a/frontend/src/png/overlay.ts b/frontend/src/png/overlay.ts
index 6841fd8..df947ba 100644
--- a/frontend/src/png/overlay.ts
+++ b/frontend/src/png/overlay.ts
@@ -237,29 +237,12 @@ export function buildOverlayPlan(input: OverlayPlanInput): OverlayPlan {
     if (extent && extent.maxP > maxRight) maxRight = extent.maxP;
   }
   const outward = maxRight + pad;
-  // Tip pixels = wood ends. Translate them by a single screen-axis offset so the
-  // dim line stays || tip-to-tip (measured span = wood tip-to-tip) and arrowheads
-  // share tip y (vertical-ish) / tip x (horizontal-ish) — no past-footprint
-  // overshoot from (rx,ry)*outward (#69). Clearance magnitude matches classic
-  // axis-right mid (centerline + r*outward).
-  const tipOriented = pickBottomTowardTop(seg.tipStart, seg.tipEnd);
-  const aClassic: [number, number] = [bottom[0] + rx * outward, bottom[1] + ry * outward];
-  const bClassic: [number, number] = [top[0] + rx * outward, top[1] + ry * outward];
-  const tipMidX = (tipOriented.bottom[0] + tipOriented.top[0]) / 2;
-  const tipMidY = (tipOriented.bottom[1] + tipOriented.top[1]) / 2;
-  const classicMidX = (aClassic[0] + bClassic[0]) / 2;
-  const classicMidY = (aClassic[1] + bClassic[1]) / 2;
-  let aSrc: [number, number];
-  let bSrc: [number, number];
-  if (Math.abs(uy) >= Math.abs(ux)) {
-    const dx = classicMidX - tipMidX;
-    aSrc = [tipOriented.bottom[0] + dx, tipOriented.bottom[1]];
-    bSrc = [tipOriented.top[0] + dx, tipOriented.top[1]];
-  } else {
-    const dy = classicMidY - tipMidY;
-    aSrc = [tipOriented.bottom[0], tipOriented.bottom[1] + dy];
-    bSrc = [tipOriented.top[0], tipOriented.top[1] + dy];
-  }
+  // Classic dimensioning (#70): centerline tip stations (robust 0.2%/99.8% axial
+  // percentiles from maskAxisSegment — keeps #69 speck immunity) offset by pure
+  // axis-right (rx,ry)*outward. Length stays || approved (ux,uy); no screen-only
+  // tip translation (that made a→b follow tip-to-tip ≠ axis on irregular wood).
+  const aSrc: [number, number] = [bottom[0] + rx * outward, bottom[1] + ry * outward];
+  const bSrc: [number, number] = [top[0] + rx * outward, top[1] + ry * outward];
   const midSrc: [number, number] = [(aSrc[0] + bSrc[0]) / 2, (aSrc[1] + bSrc[1]) / 2];
   // Nudge label further outward a bit (axis-right of dim line)
   const labelSrc: [number, number] = [midSrc[0] + rx * (scale * 0.4), midSrc[1] + ry * (scale * 0.4)];