Add extra guards around field registration

Author: robotgryphon

src/main/java/dev/compactmods/crafting/field/ActiveWorldFields.java

@@ -11,7 +11,10 @@
 import dev.compactmods.crafting.api.field.IMiniaturizationField;
 import dev.compactmods.crafting.network.FieldDeactivatedPacket;
 import dev.compactmods.crafting.network.NetworkHandler;
+import dev.compactmods.crafting.projector.FieldProjectorBlock;
 import dev.compactmods.crafting.projector.FieldProjectorTile;
+import dev.compactmods.crafting.projector.ProjectorHelper;
+import net.minecraft.block.BlockState;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.ChunkPos;
@@ -72,12 +75,28 @@ public IMiniaturizationField registerField(IMiniaturizationField field) {
         laziness.put(center, lazy);
         field.setRef(lazy);
 
+        final Optional<BlockPos> anyMissing = ProjectorHelper
+                .getMissingProjectors(level, field.getFieldSize(), field.getCenter())
+                .findFirst();
+
+        if(anyMissing.isPresent()) {
+            CompactCrafting.LOGGER.warn("Trying to register an active field with missing projector at: {}", anyMissing.get());
+            return field;
+        }
+
         field.getProjectorPositions().forEach(pos -> {
-            TileEntity tileAt = level.getBlockEntity(pos);
-            if(tileAt instanceof FieldProjectorTile) {
-                ((FieldProjectorTile) tileAt).setFieldRef(lazy);
+            BlockState stateAt = level.getBlockState(pos);
+            if(!(stateAt.getBlock() instanceof FieldProjectorBlock))
+                return;
+
+            if(stateAt.hasTileEntity()) {
+                TileEntity tileAt = level.getBlockEntity(pos);
+                if (tileAt instanceof FieldProjectorTile) {
+                    ((FieldProjectorTile) tileAt).setFieldRef(lazy);
+                }
             }
         });
+        
         lazy.addListener(lo -> {
             lo.ifPresent(this::unregisterField);
         });

src/main/java/dev/compactmods/crafting/projector/ProjectorHelper.java

@@ -1,5 +1,6 @@
 package dev.compactmods.crafting.projector;
 
+import javax.annotation.Nonnull;
 import java.util.Optional;
 import java.util.stream.Stream;
 import dev.compactmods.crafting.api.field.MiniaturizationFieldSize;
@@ -108,9 +109,7 @@ public static Stream<BlockPos> getMissingProjectors(IBlockReader level, BlockPos
             MiniaturizationFieldSize size = fieldSize.get();
             BlockPos center = size.getCenterFromProjector(initialProjector, projectorFacing);
 
-            return size.getProjectorLocations(center)
-                    // inverted filter - if the projector doesn't point to the center or isn't a projector, add to list
-                    .filter(proj -> !projectorFacesCenter(level, proj, center, size));
+            return getMissingProjectors(level, size, center);
         } else {
             // No opposing projector to limit field size.
             // Scan for a cross-axis projector to try to limit.
@@ -123,15 +122,21 @@ public static Stream<BlockPos> getMissingProjectors(IBlockReader level, BlockPos
                 MiniaturizationFieldSize matchedSize = firstMatchedSize.get();
 
                 BlockPos matchedCenter = matchedSize.getCenterFromProjector(initialProjector, projectorFacing);
-                return matchedSize.getProjectorLocations(matchedCenter)
-                        .filter(proj -> !ProjectorHelper.projectorFacesCenter(level, proj, matchedCenter, matchedSize));
+                return ProjectorHelper.getMissingProjectors(level, matchedSize, matchedCenter);
             } else {
                 // Need an opposing projector set up to limit size
                 return ProjectorHelper.getValidOppositePositions(initialProjector, projectorFacing);
             }
         }
     }
 
+    @Nonnull
+    public static Stream<BlockPos> getMissingProjectors(IBlockReader level, MiniaturizationFieldSize size, BlockPos center) {
+        return size.getProjectorLocations(center)
+                // inverted filter - if the projector doesn't point to the center or isn't a projector, add to list
+                .filter(proj -> !projectorFacesCenter(level, proj, center, size));
+    }
+
     public static boolean projectorFacesCenter(IBlockReader world, BlockPos proj, BlockPos actualCenter, MiniaturizationFieldSize size) {
         return FieldProjectorBlock.getDirection(world, proj)
                 .map(projFacing -> size.getCenterFromProjector(proj, projFacing).equals(actualCenter))