From fd608ba2171aa4690876bb456e8de69ccbd8e8e4 Mon Sep 17 00:00:00 2001
From: Georg Tomitsch <georg@tomitsch.net>
Date: Fri, 5 Jun 2026 15:15:47 +0200
Subject: [PATCH] Checkpoint cover segment legality

---
 public/js/webgl-book-shape-lab.js | 14 +++++++++++++-
 public/webgl-book-shape-lab.html  |  2 +-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/public/js/webgl-book-shape-lab.js b/public/js/webgl-book-shape-lab.js
index 73eb656..a11d64a 100644
--- a/public/js/webgl-book-shape-lab.js
+++ b/public/js/webgl-book-shape-lab.js
@@ -679,7 +679,7 @@ function scoreSupportedPoint(candidate, previous, tangent, supportTangent, angle
         supportError = closestDistance - bundleSpacing;
     } else {
         const floor = coverTopYAtX(candidate.x) + coverClearance(bundleCount);
-        supportViolation = Math.max(0, floor - candidate.y);
+        supportViolation = coverSegmentViolation(previous, candidate, bundleCount);
         if (!allowViolation && supportViolation > 0.00001) return Number.POSITIVE_INFINITY;
         supportError = candidate.y - floor;
     }
@@ -693,6 +693,18 @@ function scoreSupportedPoint(candidate, previous, tangent, supportTangent, angle
     return Math.abs(supportError) * 1200 + supportViolation * 100000 + backward * 100000 + supportAlignment * 0.85 + bend * 0.22 + angleDelta * 0.04 + outwardTarget * 0.01 + targetHeight * 0.006;
 }
 
+function coverSegmentViolation(previous, candidate, bundleCount) {
+    const clearance = coverClearance(bundleCount);
+    let violation = 0;
+    for (let sample = 1; sample <= 6; sample += 1) {
+        const t = sample / 6;
+        const x = THREE.MathUtils.lerp(previous.x, candidate.x, t);
+        const y = THREE.MathUtils.lerp(previous.y, candidate.y, t);
+        violation = Math.max(violation, coverTopYAtX(x) + clearance - y);
+    }
+    return Math.max(0, violation);
+}
+
 function closestPointOnPolyline(point, polyline) {
     let best = polyline[0];
     let bestDistance = Number.POSITIVE_INFINITY;
diff --git a/public/webgl-book-shape-lab.html b/public/webgl-book-shape-lab.html
index edd9b5b..c487c36 100644
--- a/public/webgl-book-shape-lab.html
+++ b/public/webgl-book-shape-lab.html
@@ -74,6 +74,6 @@
         <button id="fast_forward" type="button">Fast Forward</button>
         <output id="flip_count">0 / 10</output>
     </div>
-    <script type="module" src="/js/webgl-book-shape-lab.js?v=task2-grid-aligned-1"></script>
+    <script type="module" src="/js/webgl-book-shape-lab.js?v=cover-segment-floor-1"></script>
 </body>
 </html>