2 files changed, 25 insertions, 11 deletions
diff --git a/src/main/java/gregtech/api/metatileentity/CoverableTileEntity.java b/src/main/java/gregtech/api/metatileentity/CoverableTileEntity.java
index dd1eb24960..6adf7d2f1d 100644
--- a/src/main/java/gregtech/api/metatileentity/CoverableTileEntity.java
+++ b/src/main/java/gregtech/api/metatileentity/CoverableTileEntity.java
@@ -80,6 +80,7 @@ public abstract class CoverableTileEntity extends BaseTileEntity implements ICov
 
     // New Cover Information
     protected final CoverInfo[] coverInfos = new CoverInfo[] { null, null, null, null, null, null };
+    private byte validCoversMask;
 
     protected byte[] mSidedRedstone = new byte[] { 15, 15, 15, 15, 15, 15 };
     protected boolean mRedstone = false;
@@ -182,9 +183,15 @@ public abstract class CoverableTileEntity extends BaseTileEntity implements ICov
     public abstract boolean isStillValid();
 
     protected boolean doCoverThings() {
-        for (ForgeDirection side : ForgeDirection.VALID_DIRECTIONS) {
-            if (!tickCoverAtSide(side)) return false;
+        byte validCoversMask = this.validCoversMask;
+        if (validCoversMask == 0) return true;
+
+        ForgeDirection[] validDirections = ForgeDirection.VALID_DIRECTIONS;
+        for (int i = Integer.numberOfTrailingZeros(validCoversMask); i < 6; i++) {
+            if (((validCoversMask >>> i) & 1) == 0) continue;
+            if (!tickCoverAtSide(validDirections[i])) return false;
         }
+
         return true;
     }
 
@@ -349,16 +356,23 @@ public abstract class CoverableTileEntity extends BaseTileEntity implements ICov
         return getCoverInfoAtSide(side).getCoverBehavior();
     }
 
-    public void setCoverInfoAtSide(ForgeDirection side, CoverInfo coverInfo) {
-        if (side != ForgeDirection.UNKNOWN) coverInfos[side.ordinal()] = coverInfo;
+    public final void setCoverInfoAtSide(ForgeDirection side, CoverInfo coverInfo) {
+        if (side != ForgeDirection.UNKNOWN) {
+            coverInfos[side.ordinal()] = coverInfo;
+
+            byte sideMask = (byte) (1 << side.ordinal());
+            validCoversMask &= (byte) ~sideMask;
+            if (coverInfo.isValid()) validCoversMask |= sideMask;
+        }
     }
 
     @Override
-    public CoverInfo getCoverInfoAtSide(ForgeDirection side) {
+    public final CoverInfo getCoverInfoAtSide(ForgeDirection side) {
         final int ordinalSide = side.ordinal();
         if (side != ForgeDirection.UNKNOWN) {
-            if (coverInfos[ordinalSide] == null) coverInfos[ordinalSide] = new CoverInfo(side, this);
-            return coverInfos[side.ordinal()];
+            CoverInfo coverInfo = coverInfos[ordinalSide];
+            if (coverInfo == null) coverInfo = (coverInfos[ordinalSide] = new CoverInfo(side, this));
+            return coverInfo;
         }
         return CoverInfo.EMPTY_INFO;
     }
diff --git a/src/main/java/gregtech/common/covers/CoverInfo.java b/src/main/java/gregtech/common/covers/CoverInfo.java
index 7f45085ead..3deafba899 100644
--- a/src/main/java/gregtech/common/covers/CoverInfo.java
+++ b/src/main/java/gregtech/common/covers/CoverInfo.java
@@ -33,8 +33,8 @@ public final class CoverInfo {
     public static final CoverInfo EMPTY_INFO = new CoverInfo(ForgeDirection.UNKNOWN, null);
     private final ForgeDirection coverSide;
     private int coverID = 0;
-    private GT_CoverBehaviorBase<?> coverBehavior = null;
-    private ISerializableObject coverData = null;
+    private GT_CoverBehaviorBase<?> coverBehavior;
+    private ISerializableObject coverData;
     private final WeakReference<ICoverable> coveredTile;
     private boolean needsUpdate = false;
 
@@ -43,6 +43,7 @@ public final class CoverInfo {
     public CoverInfo(ForgeDirection side, ICoverable aTile) {
         coverSide = side;
         coveredTile = new WeakReference<>(aTile);
+        coverBehavior = GregTech_API.sNoBehavior;
     }
 
     public CoverInfo(ForgeDirection side, int aID, ICoverable aTile, ISerializableObject aCoverData) {
@@ -89,8 +90,7 @@ public final class CoverInfo {
     }
 
     public GT_CoverBehaviorBase<?> getCoverBehavior() {
-        if (coverBehavior != null) return coverBehavior;
-        return GregTech_API.sNoBehavior;
+        return coverBehavior;
     }
 
     public ISerializableObject getCoverData() {