core: chamber floors planned into the passage h(s) profile (L152, v239; surface landing support open)

Seed 2 planned grades 9.58/6.58/8.28 deg (were 19 deg); 0 solid in 320,355 passage interior samples; 0 shell,
chamber, wall violations; envelope audit clean. Open: the upper Surface World landing plane, fitted to the surface
route, leaves 5 route + 2 chamber support samples unsupported.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Standalone/Core/src/ShapeWorldInternal.h

@@ -3836,6 +3836,7 @@ private:
         std::array<double,2> lowerLandingFloorGradient{};
         double lowerLandingRadiusSubvoxels=0.0;
         std::size_t routeEndControlIndex=0;
+        bool floorProfileIncludesLandingChambers=false;
     };
     struct FPassageSegmentData
     {
@@ -3937,6 +3938,8 @@ private:
                     +profileT*profileSegment.authoredFloorZDelta;
             }
         }
+        if(constants.floorProfileIncludesLandingChambers)
+            return plannedFloor+floorDepthSubvoxels;
         const double upperBlendFloor=VoxelForgeCore::PassageSpline::BlendUpperMouthFloorAtXY(
             constants.upperMouthReceivingRoute,queryXSubvoxels,queryYSubvoxels,
             plannedFloor,constants.upperMouthX,constants.upperMouthY,
@@ -5112,6 +5115,8 @@ private:
                 passage.lowerMouthControlIndex,1,passage.controlPoints.size()-1);
             auto& constants=PassageComposerConstants[passageIndex];
             constants.routeEndControlIndex=routeEnd;
+            constants.floorProfileIncludesLandingChambers=
+                passage.floorProfileIncludesLandingChambers;
             for(std::size_t axis=0;axis<3;++axis)
             {
                 constants.upperLandingFloorCenterSubvoxels[axis]=static_cast<double>(
@@ -5177,8 +5182,10 @@ private:
                     upperMouthFloorDepth=std::max(upperMouthFloorDepth,
                         std::max(0.0,(controls.front()[2]-routeHeight)/qPerMetre
                             +constants.upperMouthPlayerCenterHeightMetres));
-                    if(upperStratum->generatorKind=="TunnelNetwork"
+                    if(!passage.floorProfileIncludesLandingChambers
+                        &&(upperStratum->generatorKind=="TunnelNetwork"
                         ||upperStratum->generatorKind=="SurfaceWorld")
+                        )
                         VoxelForgeCore::PassageSpline::BlendEndpointFloorToRoute(
                             controls,plannedFloorProfile,0,route,qPerMetre,
                             constants.upperMouthPlayerCenterHeightMetres);
@@ -5226,9 +5233,10 @@ private:
                     &&distanceSquared<=std::pow(controls[routeEnd][3]
                         +2.0*qPerMetre,2.0))
                 {
-                    VoxelForgeCore::PassageSpline::BlendEndpointFloorToRoute(
-                        controls,plannedFloorProfile,routeEnd,
-                        constants.lowerMouthReceivingRoute,qPerMetre);
+                    if(!passage.floorProfileIncludesLandingChambers)
+                        VoxelForgeCore::PassageSpline::BlendEndpointFloorToRoute(
+                            controls,plannedFloorProfile,routeEnd,
+                            constants.lowerMouthReceivingRoute,qPerMetre);
                     constants.lowerMouthX=controls[routeEnd][0];
                     constants.lowerMouthY=controls[routeEnd][1];
                     constants.lowerMouthPlannedFloor=plannedFloorProfile[routeEnd];