wip(L25, side branch): FI helix enclosed in a 13 m rock root; support never created in open air

Fixes the L24 ribbon (owner request). NOT merged: the open-air support gate leaves ~4,000 unsupported samples on every SurfaceWorld-recipe passage style (TN -> SW), a walkability regression. L26 fixes that on this branch. See Linux25/REPORT.md. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01CSFYgsdW8ejZSyiMf4qRSX
2026-10-21 00:38:57 +02:00
1 parent cb9236c265
commit ef789aaa00
@@ -281,7 +281,7 @@ namespace floating_island_detail
            ? recipe.ownerVoxelSizeMicrons / ScaleGcd : 0;
        const std::uint32_t ExpectedDenominator = ScaleGcd > 0
            ? recipe.coreVoxelSizeMicrons / ScaleGcd : 0;
-        if (recipe.schemaVersion != 1 || recipe.geometryVersion < 1 || recipe.geometryVersion > 5
+        if (recipe.schemaVersion != 1 || recipe.geometryVersion < 1 || recipe.geometryVersion > 7
            || (recipe.geometryVersion == 1
                && (recipe.crustDepthBonusQ16 != 0 || recipe.rootDepthRatioQ16 != 0))
            || recipe.unitsPerVoxel != Q
@@ -756,7 +756,9 @@ namespace floating_island_detail
        if (recipe.geometryVersion >= 5 && island.ordinal == recipe.anchorIslandOrdinal
            && recipe.anchorRootBottomZSubvoxels < island.bottomZSubvoxels)
        {
-            const double rootTop = static_cast<double>(island.bottomZSubvoxels);
+            // The central buttress must meet the island crust underside. IslandBottom
+            // also includes the four shorter root lobes and sits below that surface.
+            const double rootTop = static_cast<double>(IslandCrustBottom(recipe, island));
            const double rootBottom = static_cast<double>(recipe.anchorRootBottomZSubvoxels);
            const double depth = std::max(1.0, rootTop - rootBottom);
            const double blend = std::clamp(static_cast<double>(recipe.anchorRootRadiusSubvoxels)
@@ -1330,7 +1332,7 @@ std::optional<FloatingIslandManifestV1> FloatingIslandManifestV1::FromJson(
                manifest.recipe.anchorRootBottomZSubvoxels)
            ||!floating_island_detail::ReadInteger(recipeValue.Get("anchor_mouth_offset_q"),
                manifest.recipe.anchorMouthOffsetSubvoxels))
-        {error="floating-island geometry version 5 is missing a passage-rooted anchor field";return std::nullopt;}
+        {error="floating-island geometry version 7 is missing a passage-rooted anchor field";return std::nullopt;}
    }
    if (!floating_island_detail::ReadU32(root.Get("schema_version"), schema)
        || !floating_island_detail::ReadHash(root.Get("content_hash"), manifestHash)
@@ -550,6 +550,14 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
    const auto routeAnchor=[](const ResolvedLayoutStratumV2& s,bool departure,
        std::array<std::int64_t,3>& out)
    {
+        if(departure)
+            for(const auto& a:s.anchors)
+                if(a.kind=="passage_anchor"&&a.values.size()>=10)
+                {out={a.values[7],a.values[8],a.values[9]};return true;}
+        if(!departure)
+            for(const auto& a:s.anchors)
+                if(a.kind=="passage_arrival"&&a.values.size()>=3)
+                {out={a.values[0],a.values[1],a.values[2]};return true;}
        const ResolvedLayoutAnchorV2* selected=nullptr;
        for(const auto& a:s.anchors)
            if(a.kind=="route_point"&&a.values.size()>=3)
@@ -597,8 +605,9 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
        // Leave room for the capsule and bounded wall relief at the floor/wall seam.
        const std::int64_t mouthRadius=std::max<std::int64_t>(static_cast<std::int64_t>(std::llround(1.5*qPerMetre)),
            cfg?cfg->mouthRadiusSubvoxels:0);
-        const std::int64_t midRadius=std::max<std::int64_t>(mouthRadius,
-            cfg?cfg->midRadiusSubvoxels:0);
+        const std::int64_t midRadius=std::max<std::int64_t>(
+            static_cast<std::int64_t>(std::llround(1.5*qPerMetre)),
+            cfg?cfg->midRadiusSubvoxels:mouthRadius);
        const std::int64_t reachMinimum=cfg?std::max<std::int64_t>(0,cfg->reachMinimumSubvoxels):8*qPerMetre;
        const std::int64_t reachMaximum=cfg?std::max<std::int64_t>(reachMinimum,cfg->reachMaximumSubvoxels):24*qPerMetre;
        const std::uint32_t style=cfg?std::min<std::uint32_t>(cfg->style,3u):1u;
@@ -624,7 +633,9 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                for(const auto& anchor:upper.anchors)
                    if(anchor.kind=="passage_anchor"&&anchor.values.size()>=7)
                    {passageAnchor=&anchor;break;}
-            const bool anchoredSpiral=style==2&&passageAnchor!=nullptr;
+            const bool anchoredIslandPassage=passageAnchor!=nullptr
+                &&upper.generatorKind=="FloatingIslands";
+            const bool anchoredSpiral=style==2&&anchoredIslandPassage;
            if(!hasUpperRoute||!hasLowerRoute)
            {
                const auto xy=PassageRandomXY(PassageSeed(seed,upper.strateIndex,lower.strateIndex,
@@ -652,7 +663,10 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
            std::array<std::int64_t,2> upperTangent{},lowerTangent{};
            const bool hasUpperTangent=hasUpperRoute
                &&routeTangent(upper,true,upperTangent);
-            const bool hasLowerTangent=hasLowerRoute
+            const bool hasPassageArrival=std::any_of(lower.anchors.begin(),lower.anchors.end(),
+                [](const auto& anchor){return anchor.kind=="passage_arrival"
+                    &&anchor.values.size()>=3;});
+            const bool hasLowerTangent=hasLowerRoute&&!hasPassageArrival
                &&routeTangent(lower,false,lowerTangent);

            const std::int64_t outerRingRadius=std::max<std::int64_t>(1,
@@ -671,6 +685,8 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                        std::max<std::int64_t>(0,cfg?cfg->cascadeLedgeSubvoxels:0)
                            *static_cast<std::int64_t>(cfg?cfg->cascadeSteps:4)),
                    mouthRadius+2*qPerMetre,outerRingRadius);
+            if(anchoredIslandPassage)
+                ringRadius=std::min(ringRadius,mouthRadius+qPerMetre/2);
            std::uint32_t phase=static_cast<std::uint32_t>(PassageSeed(seed,
                upper.strateIndex,lower.strateIndex,connection,0x50484153u)%16);
            if(hasUpperRoute)
@@ -700,7 +716,7 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                    +clockwiseTangentY*upperTangent[1]>=0.0;
            }
            const int direction=clockwise?1:-1;
-            constexpr std::int64_t TargetGradeQ16=12500; // leave margin below the 15-degree contract.
+            constexpr std::int64_t TargetGradeQ16=12500; // leave margin below the 15-degree helix contract.
            const std::int64_t wormRadialWobble=std::min<std::int64_t>(
                std::max<std::int64_t>(0,wander/3),2*qPerMetre);
            const std::int64_t wormCenterWobble=std::min<std::int64_t>(
@@ -716,10 +732,14 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                    const double loop=static_cast<double>(loopIndex);
                    const double phaseA=loop*0.6180339887498948+0.37;
                    const double phaseB=loop*0.4142135623730950+1.11;
+                    const double jitterX=static_cast<double>(wormCenterWobble)*std::sin(phaseB);
+                    const double jitterY=static_cast<double>(wormCenterWobble)*std::cos(phaseB);
                    radius+=static_cast<double>(wormRadialWobble)
                        *std::sin(angle+phaseA);
-                    centerX=static_cast<double>(wormCenterWobble)*std::sin(phaseB);
-                    centerY=static_cast<double>(wormCenterWobble)*std::cos(phaseB);
+                    centerX=jitterX+(anchoredIslandPassage&&passageAnchor
+                        ?static_cast<double>(passageAnchor->values[0]):0.0);
+                    centerY=jitterY+(anchoredIslandPassage&&passageAnchor
+                        ?static_cast<double>(passageAnchor->values[1]):0.0);
                }
                else if(pathStyle==3u)
                {
@@ -730,6 +750,11 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                            cfg->cascadeLedgeSubvoxels):0));
                    radius-=ledge*(0.5-0.5*std::cos(angle*steps));
                }
+                if(pathStyle!=1u&&anchoredIslandPassage&&passageAnchor)
+                {
+                    centerX=static_cast<double>(passageAnchor->values[0]);
+                    centerY=static_cast<double>(passageAnchor->values[1]);
+                }
                return std::array<std::int64_t,2>{
                    static_cast<std::int64_t>(std::llround(centerX+radius*directions[directionIndex][0]/65536.0)),
                    static_cast<std::int64_t>(std::llround(centerY+radius*directions[directionIndex][1]/65536.0))};
@@ -748,7 +773,11 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                const std::int64_t anchorY=passageAnchor->values[1];
                const std::int64_t rootRadius=passageAnchor->values[2];
                const std::int64_t rootBottom=passageAnchor->values[5];
-                helixBedrockZ=rootBottom!=0?rootBottom:contentZQ(upper.bedrock.topMicrometres);
+                const std::int64_t bedrockTop=rootBottom!=0?rootBottom
+                    :contentZQ(upper.bedrock.topMicrometres);
+                // Passage route heights are player-center positions. End one capsule
+                // half-height above the bedrock top so the final ramp step is walkable.
+                helixBedrockZ=bedrockTop+qPerMetre;
                const std::int64_t helixRadius=spiralRadius;
                if(rootRadius<helixRadius+midRadius+qPerMetre/4
                    ||std::hypot(static_cast<double>(upperMouth[0]-anchorX),
@@ -796,6 +825,8 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                helixEndIndex=xy.size()-1;
                hasAnchorHelix=helixEndIndex>0;
            }
+            const std::int64_t routeGradeQ16=hasAnchorHelix
+                &&lower.generatorKind=="SurfaceWorld"?8000:TargetGradeQ16;
            const std::array<std::int64_t,2> firstRing=ringPoint(phase);
            if(hasAnchorHelix&&pathStyle==1u)
            {
@@ -843,12 +874,14 @@ bool PlanResolvedLayoutPassagesV1(ResolvedLayoutSnapshotV3& layout,std::int32_t
                const std::size_t start=hasAnchorHelix?helixEndIndex:0;
                for(std::size_t i=start+1;i<xy.size();++i)
                    total+=distanceQ(xy[i][0]-xy[i-1][0],xy[i][1]-xy[i-1][1]);
+                if(!hasLowerTangent&&!xy.empty())
+                    total+=distanceQ(lowerMouth[0]-xy.back()[0],lowerMouth[1]-xy.back()[1]);
                return total;
            };
            while(loops<256)
            {
                totalHorizontal=measurePath();
-                if(totalHorizontal*static_cast<std::uint64_t>(TargetGradeQ16)
+                if(totalHorizontal*static_cast<std::uint64_t>(routeGradeQ16)
                    >=static_cast<std::uint64_t>(verticalDistance)*65536ull)break;
                for(int step=1;step<=16;++step)
                {
@@ -110,6 +110,9 @@ public:
        const auto composeRouteMouthSupport=[&](std::int32_t strateIndex,
            const std::array<std::int64_t,3>& mouth,bool departure)
        {
+            // Support is allowed to reinforce native solid terrain only. Without this
+            // guard the route-point tread stamps a floating shelf into an open stratum.
+            if(!(density<0.0f))return;
            const double mouthDx=qx-static_cast<double>(mouth[0]);
            const double mouthDy=qy-static_cast<double>(mouth[1]);
            const double routeSupportReach=13.0*qPerMetre;
@@ -159,26 +162,26 @@ public:
                    std::clamp(Z-floorVoxels,-floorThickness,0.0)));
            }
        };
-        // Seed the route floor first. The bore carve below reopens any overlap at the
-        // mouth, then applies its own lower tread, so neither shape blocks the capsule.
+        // Keep the native surface route connected to the entrance. Passage carving
+        // then removes only the parts that overlap the tunnel, whose own tread owns
+        // the interior ramp.
        for(const auto& passage:ResolvedLayout->passages)
-        {
-            composeRouteMouthSupport(passage.upperStrateIndex,passage.upperMouthSubvoxels,true);
-            // The lower mouth emerges into its native terrain. Keep the passage tread
-            // support, but do not stamp short, flat route-anchor shelves over that cave mouth.
-        }
+            composeRouteMouthSupport(passage.upperStrateIndex,
+                passage.upperMouthSubvoxels,true);
        for(const auto& passage:ResolvedLayout->passages)
        {
            if(passage.controlPoints.size()<2)continue;
            const double placementRadiusQ=static_cast<double>(passage.placementRadiusSubvoxels)
                +static_cast<double>(passage.midRadiusSubvoxels);
-            if(qx*qx+qy*qy>placementRadiusQ*placementRadiusQ)continue;
+            if(qx*qx+qy*qy>placementRadiusQ*placementRadiusQ)
+                continue;
            const double firstFloorQ=passage.controlPoints.front().positionSubvoxels[2]
                -passage.controlPoints.front().radiusSubvoxels+playerCenterAboveFloorQ;
            const double lastFloorQ=passage.controlPoints.back().positionSubvoxels[2]
                -passage.controlPoints.back().radiusSubvoxels+playerCenterAboveFloorQ;
            if(qz>firstFloorQ+2.0*passage.mouthRadiusSubvoxels
-                ||qz<lastFloorQ-2.0*passage.mouthRadiusSubvoxels)continue;
+                ||qz<lastFloorQ-2.0*passage.mouthRadiusSubvoxels)
+                continue;
            const auto floorProfile=[&](const auto& point)
            {return point.positionSubvoxels[2]-point.radiusSubvoxels+playerCenterAboveFloorQ;};
            const std::ptrdiff_t lastIndex=static_cast<std::ptrdiff_t>(passage.controlPoints.size())-1;
@@ -237,21 +240,6 @@ public:
            const auto& nearestB=passage.controlPoints[static_cast<std::size_t>(bestIndex+1)];
            const double nearestRadius=nearestA.radiusSubvoxels+bestT*(
                static_cast<double>(nearestB.radiusSubvoxels)-nearestA.radiusSubvoxels);
-            const double nearestDx=static_cast<double>(nearestB.positionSubvoxels[0])
-                -nearestA.positionSubvoxels[0];
-            const double nearestDy=static_cast<double>(nearestB.positionSubvoxels[1])
-                -nearestA.positionSubvoxels[1];
-            const double nearestHorizontalSq=nearestDx*nearestDx+nearestDy*nearestDy;
-            const double supportPathT=nearestHorizontalSq>0.0
-                ?std::clamp(((qx-nearestA.positionSubvoxels[0])*nearestDx
-                    +(qy-nearestA.positionSubvoxels[1])*nearestDy)/nearestHorizontalSq,0.0,1.0)
-                :bestT;
-            const double supportPathRadius=nearestA.radiusSubvoxels+supportPathT*(
-                static_cast<double>(nearestB.radiusSubvoxels)-nearestA.radiusSubvoxels);
-            const double supportPathPlayerCenterZ=nearestA.positionSubvoxels[2]+supportPathT*(
-                static_cast<double>(nearestB.positionSubvoxels[2])-nearestA.positionSubvoxels[2])
-                -supportPathRadius+playerCenterAboveFloorQ;
-            const double nearestPlayerCenterZ=supportPathPlayerCenterZ;
            const double distanceToCenter=std::max(1.0e-9,bestSignedDistance+nearestRadius);
            const double verticalWallAlignment=distanceToCenter>1.0e-9
                ?std::clamp(-(qz-(nearestA.positionSubvoxels[2]+bestT*(
@@ -265,11 +253,6 @@ public:
            // Positive density is air; rough rock is cut with full side/ceiling detail and
            // gentler relief on the gravity-facing wall so the supported tread stays open.
            composed=std::max(composed,static_cast<float>(-roughSignedDistance/Q));
-            // At tight bends, keep the tread tied to the player-center profile selected
-            // by horizontal path position so vertical probe offsets cannot shift the ramp.
-            const bool fallbackSupport=qz>=nearestPlayerCenterZ-1.50*qPerMetre;
-            const double supportThicknessVoxels=fallbackSupport
-                ?qPerMetre/Q:0.5*qPerMetre/Q;
            double bestSupportDistanceSquared=std::numeric_limits<double>::infinity();
            const auto considerSupportSegment=[&](std::ptrdiff_t index)
            {
@@ -293,21 +276,28 @@ public:
                    static_cast<double>(segmentB.positionSubvoxels[2])-segmentA.positionSubvoxels[2]);
                const double radius=segmentA.radiusSubvoxels+supportT*(
                    static_cast<double>(segmentB.radiusSubvoxels)-segmentA.radiusSubvoxels);
-                const double supportPlayerCenterZ=centerZ-radius+playerCenterAboveFloorQ;
-                if(fallbackSupport)
-                {
-                    const double supportProfileError=std::abs(
-                        supportPlayerCenterZ-nearestPlayerCenterZ);
-                    if(supportProfileError>0.06*qPerMetre)return;
-                }
                const double horizontalX=qx-centerX,horizontalY=qy-centerY;
                const double horizontalDistance=DeterministicSqrt(horizontalX*horizontalX
                    +horizontalY*horizontalY);
+                const double supportPlayerCenterZ=centerZ-radius+playerCenterAboveFloorQ;
+                const double supportQueryDepth=supportPlayerCenterZ-qz;
+                // Support belongs just below the avatar's foot plane. Queries within
+                // the capsule body, or a neighbouring coil's overlapping bore, must
+                // not turn that tread into a ceiling or mid-air shelf.
+                if(supportQueryDepth<0.93*qPerMetre||supportQueryDepth>1.30*qPerMetre)return;
+                const bool fallbackSupport=qz>=supportPlayerCenterZ-1.50*qPerMetre;
+                const double supportThicknessVoxels=fallbackSupport
+                    ?qPerMetre/Q:0.5*qPerMetre/Q;
                const double floorQ=centerZ-radius+floorOffset*qPerMetre;
                const double floorVoxels=floorQ/Q;
+                // Keep the supported ramp to a comfortable walking width. Extending a
+                // full bore-radius shelf across overlapping helix coils can block the
+                // capsule on the neighbouring turn.
+                const bool lowerMouthBodyOverlap=index>=lowerMouthIndex-2
+                    &&supportQueryDepth<0.98*qPerMetre;
+                const double supportHalfWidth=std::min(radius,
+                    (lowerMouthBodyOverlap?0.90:1.25)*qPerMetre);
                if(Z<floorVoxels-supportThicknessVoxels||Z>floorVoxels+1.0/Q)return;
-                const double supportHalfWidth=fallbackSupport?radius
-                    :std::max(0.0,radius+2.0*qPerMetre);
                if(horizontalDistance>supportHalfWidth)return;
                const double supportDistanceSq=horizontalDistance*horizontalDistance
                    +(Z-floorVoxels)*(Z-floorVoxels);
@@ -317,11 +307,30 @@ public:
                bestSupportDensity=std::clamp(Z-floorVoxels,
                    -supportThicknessVoxels,0.0);
            };
-            const std::ptrdiff_t supportBegin=std::max<std::ptrdiff_t>(0,bestIndex-1);
-            const std::ptrdiff_t supportEnd=std::min<std::ptrdiff_t>(lastIndex-1,bestIndex+1);
+            std::ptrdiff_t supportCenterIndex=bestIndex;
+            if(bestIndex<lowerMouthIndex)
+            {
+                // A helix can have multiple centerlines at one XY. Select the tread
+                // whose floor is just below this density query, not the closest wall.
+                const double supportProfileTarget=qz+0.93*qPerMetre;
+                const auto supportProfile=std::lower_bound(passage.controlPoints.begin(),mainEnd,
+                    supportProfileTarget,[&](const auto& point,double value)
+                        {return floorProfile(point)>value;});
+                const std::ptrdiff_t profileIndex=std::clamp<std::ptrdiff_t>(
+                    supportProfile-passage.controlPoints.begin(),0,lowerMouthIndex);
+                // At floor height the nearest 3D centerline can belong to the next
+                // coil below. The descending floor profile identifies the coil that
+                // owns this tread, even when it is more than eight control points away.
+                supportCenterIndex=profileIndex;
+            }
+            const std::ptrdiff_t supportBegin=std::max<std::ptrdiff_t>(0,supportCenterIndex-1);
+            const std::ptrdiff_t supportEnd=std::min<std::ptrdiff_t>(lastIndex-1,
+                supportCenterIndex+1);
            for(std::ptrdiff_t index=supportBegin;index<=supportEnd;++index)
                considerSupportSegment(index);
-            if(hasSupportFloor)
+            // Keep route treads inside the native rock envelope. Carving may reopen the
+            // floor above this point, but a support cannot create a new surface in air.
+            if(hasSupportFloor&&density<0.0f)
                composed=std::min(composed,static_cast<float>(bestSupportDensity));
        }
        return composed;