c

core/src/main/java/art/arcane/iris/engine/object/IrisObject.java

@@ -963,6 +963,7 @@ public class IrisObject extends IrisRegistrant {
         int lowest = Integer.MAX_VALUE;
         int topLayer = Integer.MIN_VALUE;
         int vacuumLowest = Integer.MAX_VALUE;
+        int vacuumHighest = Integer.MIN_VALUE;
         y += yrand;
         readLock.lock();
 
@@ -1132,6 +1133,9 @@ public class IrisObject extends IrisRegistrant {
                     if (vacuuming && yy < vacuumLowest) {
                         vacuumLowest = yy;
                     }
+                    if (vacuuming && yy > vacuumHighest) {
+                        vacuumHighest = yy;
+                    }
                 }
             }
         } catch (Throwable e) {
@@ -1370,7 +1374,7 @@ public class IrisObject extends IrisRegistrant {
             int highZ = IrisObjectVacuum.footprintHigh(rotDim.getBlockZ());
             int centerX = x + config.getTranslate().getX();
             int centerZ = z + config.getTranslate().getZ();
-            vacuumTerrain(placer, config, centerX, centerZ, lowX, highX, lowZ, highZ, vacuumLowest);
+            vacuumTerrain(placer, config, centerX, centerZ, lowX, highX, lowZ, highZ, vacuumLowest, vacuumHighest);
         }
 
         if (heightmap != null) {
@@ -1409,7 +1413,7 @@ public class IrisObject extends IrisRegistrant {
                 + "(forcePlace=false, fromBottom=false, mode!=FLOATING). Skipping to protect bedrock.");
     }
 
-    private void vacuumTerrain(IObjectPlacer placer, IrisObjectPlacement config, int centerX, int centerZ, int lowX, int highX, int lowZ, int highZ, int baseY) {
+    private void vacuumTerrain(IObjectPlacer placer, IrisObjectPlacement config, int centerX, int centerZ, int lowX, int highX, int lowZ, int highZ, int baseY, int topY) {
         ObjectPlaceMode mode = config.getMode();
         IrisVacuumSettings settings = config.getVacuumSettings();
         int radius = IrisObjectVacuum.resolveRadius(mode, settings);
@@ -1448,7 +1452,9 @@ public class IrisObject extends IrisRegistrant {
                         placer.set(cx, yy, cz, fill);
                     }
                 } else if (targetY < origY) {
-                    for (int yy = origY; yy > targetY; yy--) {
+                    boolean inside = IrisObjectVacuum.outset(dx, lowX, highX) == 0 && IrisObjectVacuum.outset(dz, lowZ, highZ) == 0;
+                    int carveFloor = IrisObjectVacuum.carveFloorY(targetY, topY, inside);
+                    for (int yy = origY; yy >= carveFloor; yy--) {
                         placer.set(cx, yy, cz, AIR);
                     }
                 }

core/src/main/java/art/arcane/iris/engine/object/IrisObjectVacuum.java

@@ -90,4 +90,12 @@ public final class IrisObjectVacuum {
         double factor = Math.pow(t, Math.max(0.25, falloff));
         return (int) Math.round(originalY + ((meetY - originalY) * factor));
     }
+
+    public static int carveFloorY(int targetY, int objectTopY, boolean insideFootprint) {
+        int floor = targetY + 1;
+        if (insideFootprint) {
+            floor = Math.max(floor, objectTopY + 1);
+        }
+        return floor;
+    }
 }

core/src/test/java/art/arcane/iris/engine/object/IrisObjectVacuumTest.java

@@ -126,4 +126,21 @@ public class IrisObjectVacuumTest {
         assertFalse(IrisObjectVacuum.isVacuumMode(ObjectPlaceMode.PAINT));
         assertFalse(IrisObjectVacuum.isVacuumMode(ObjectPlaceMode.FLOATING));
     }
+
+    @Test
+    public void carveFloorPreservesBuriedObjectInsideFootprint() {
+        int surfaceY = 122;
+        int baseY = 110;
+        int topY = 119;
+        int meetY = baseY - 1;
+
+        int insideFloor = IrisObjectVacuum.carveFloorY(meetY, topY, true);
+        assertEquals("inside the footprint the carve must stop one above the object top", topY + 1, insideFloor);
+        assertTrue("inside carve must not reach the object's blocks", insideFloor > topY);
+        assertTrue("inside carve still removes the terrain burying the object", insideFloor <= surfaceY + 1);
+
+        int ringFloor = IrisObjectVacuum.carveFloorY(meetY, topY, false);
+        assertEquals("the ring carves down to the deformation target (the crater floor)", meetY + 1, ringFloor);
+        assertTrue("ring crater is deeper than the object-protected inside floor", ringFloor < insideFloor);
+    }
 }