Added basic API to allow access to connected blocks

Someone in some issue somewhere said there is no support for a given
connection type through tunnels, because compact machines does not have
an API and only allows Capability based connections.

This commit changes that. Other mods can now ask Machines and Tunnels
to which WorldServer and BlockPos they are connected to. Maybe this
results in more possible connection types and less spam in the issue
inbox.

Author: davenonymous

src/main/java/org/dave/compactmachines3/api/IRemoteBlockProvider.java

@@ -0,0 +1,57 @@
+package org.dave.compactmachines3.api;
+
+import net.minecraft.util.EnumFacing;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.WorldServer;
+import net.minecraftforge.fml.common.FMLCommonHandler;
+
+import javax.annotation.Nullable;
+
+/**
+ * This interface is implemented on Machines and Tunnels.
+ * The data provided here is only available on the server. Calling these
+ * methods on the client will probably crash the game. Don't do it.
+ *
+ * If you need to know stuff about the other block (e.g. whether to render
+ * a "connection-plug" or just continue with some cables) you have to
+ * network that data yourself - but you probably are already syncing the
+ * connection type of a blocks face from the server to the client anyway.
+ */
+public interface IRemoteBlockProvider {
+    /**
+     * Returns the position of the connected block. null if no block is connected.
+     * Side is only relevant for machine blocks and is ignored for tunnel blocks.
+     *
+     * @param side
+     * @return
+     */
+    @Nullable
+    BlockPos getConnectedBlockPosition(EnumFacing side);
+
+    /**
+     * Returns the dimension id of the connected block.
+     * Side is only relevant for machine blocks and is ignored for tunnel blocks.
+     * On a machine block this always returns the id of the machine dimension (-144 by default)
+     * This returns 0 if no block is connected, i.e. make sure to check the result of
+     * getConnectedBlockPosition before using this information.
+     *
+     * @param side
+     * @return
+     */
+    int getConnectedDimensionId(EnumFacing side);
+
+    /**
+     * Returns the WorldServer for the dimension of the connected block.
+     * This is just a convenience wrapper around the getConnectedDimensionId method to
+     * directly grab a reference to the world, which allows you to call getTileEntity
+     * etc.
+     *
+     * Again and as the return value implies: Don't call this on a client.
+     *
+     * @param side
+     * @return
+     */
+    default WorldServer getConnectedDimension(EnumFacing side) {
+        return FMLCommonHandler.instance().getMinecraftServerInstance().getWorld(this.getConnectedDimensionId(side));
+    }
+}

src/main/java/org/dave/compactmachines3/block/BlockMachine.java

@@ -135,7 +135,7 @@ public void neighborChanged(IBlockState state, World world, BlockPos pos, Block
         }
 
         WorldServer machineWorld = DimensionTools.getServerMachineWorld();
-        BlockPos neighborPos = te.getTunnelForSide(facing);
+        BlockPos neighborPos = te.getConnectedBlockPosition(facing);
         if(neighborPos != null && machineWorld.getTileEntity(neighborPos) instanceof TileEntityTunnel) {
             machineWorld.notifyNeighborsOfStateChange(neighborPos, Blockss.tunnel, false);
             te.alreadyNotifiedOnTick = true;

src/main/java/org/dave/compactmachines3/tile/TileEntityMachine.java

@@ -20,13 +20,10 @@
 import net.minecraftforge.common.capabilities.ICapabilityProvider;
 import net.minecraftforge.common.util.Constants;
 import net.minecraftforge.fml.common.FMLCommonHandler;
-import net.minecraftforge.fml.common.network.NetworkRegistry;
-import org.dave.compactmachines3.CompactMachines3;
+import org.dave.compactmachines3.api.IRemoteBlockProvider;
 import org.dave.compactmachines3.block.BlockMachine;
 import org.dave.compactmachines3.integration.CapabilityNullHandlerRegistry;
 import org.dave.compactmachines3.misc.ConfigurationHandler;
-import org.dave.compactmachines3.network.MessageMachineChunk;
-import org.dave.compactmachines3.network.PackageHandler;
 import org.dave.compactmachines3.reference.EnumMachineSize;
 import org.dave.compactmachines3.utility.Logz;
 import org.dave.compactmachines3.world.ChunkLoadingMachines;
@@ -36,9 +33,12 @@
 import org.dave.compactmachines3.world.tools.SpawnTools;
 import org.dave.compactmachines3.world.tools.StructureTools;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.UUID;
 
-public class TileEntityMachine extends TileEntity implements ICapabilityProvider, ITickable {
+public class TileEntityMachine extends TileEntity implements ICapabilityProvider, ITickable, IRemoteBlockProvider {
     public int coords = -1;
     private boolean initialized = false;
     public boolean alreadyNotifiedOnTick = false;
@@ -359,7 +359,13 @@ public RedstoneTunnelData getRedstoneTunnelForSide(EnumFacing side) {
         return WorldSavedDataMachines.INSTANCE.redstoneTunnels.get(this.coords).get(side);
     }
 
-    public BlockPos getTunnelForSide(EnumFacing side) {
+    @Override
+    public int getConnectedDimensionId(EnumFacing side) {
+        return ConfigurationHandler.Settings.dimensionId;
+    }
+
+    @Override
+    public BlockPos getConnectedBlockPosition(EnumFacing side) {
         if(WorldSavedDataMachines.INSTANCE == null || WorldSavedDataMachines.INSTANCE.tunnels == null) {
             return null;
         }
@@ -372,7 +378,7 @@ public BlockPos getTunnelForSide(EnumFacing side) {
     }
 
     public BlockPos getMachineWorldInsetPos(EnumFacing facing) {
-        BlockPos tunnelPos = this.getTunnelForSide(facing);
+        BlockPos tunnelPos = this.getConnectedBlockPosition(facing);
         if(tunnelPos == null) {
             return null;
         }
@@ -478,7 +484,7 @@ public boolean hasCapability(Capability<?> capability, EnumFacing facing) {
             return super.hasCapability(capability, facing);
         }
 
-        BlockPos tunnelPos = this.getTunnelForSide(facing);
+        BlockPos tunnelPos = this.getConnectedBlockPosition(facing);
         if(tunnelPos == null) {
             return false;
         }
@@ -517,7 +523,7 @@ public <T> T getCapability(Capability<T> capability, EnumFacing facing) {
             return super.getCapability(capability, facing);
         }
 
-        BlockPos tunnelPos = this.getTunnelForSide(facing);
+        BlockPos tunnelPos = this.getConnectedBlockPosition(facing);
         if(tunnelPos == null) {
             return null;
         }

src/main/java/org/dave/compactmachines3/tile/TileEntityTunnel.java

@@ -6,13 +6,40 @@
 import net.minecraft.world.WorldServer;
 import net.minecraftforge.common.capabilities.Capability;
 import net.minecraftforge.common.capabilities.ICapabilityProvider;
+import org.dave.compactmachines3.api.IRemoteBlockProvider;
 import org.dave.compactmachines3.integration.CapabilityNullHandlerRegistry;
 import org.dave.compactmachines3.utility.DimensionBlockPos;
 import org.dave.compactmachines3.world.WorldSavedDataMachines;
 import org.dave.compactmachines3.world.tools.DimensionTools;
 import org.dave.compactmachines3.world.tools.StructureTools;
 
-public class TileEntityTunnel extends BaseTileEntityTunnel implements ICapabilityProvider {
+public class TileEntityTunnel extends BaseTileEntityTunnel implements ICapabilityProvider, IRemoteBlockProvider {
+
+    @Override
+    public BlockPos getConnectedBlockPosition(EnumFacing side) {
+        DimensionBlockPos dimpos = WorldSavedDataMachines.INSTANCE.machinePositions.get(StructureTools.getCoordsForPos(this.getPos()));
+        if(dimpos == null) {
+            return null;
+        }
+
+        WorldServer realWorld = DimensionTools.getWorldServerForDimension(dimpos.getDimension());
+        if(realWorld == null || !(realWorld.getTileEntity(dimpos.getBlockPos()) instanceof TileEntityMachine)) {
+            return null;
+        }
+
+        EnumFacing machineSide = this.getMachineSide();
+        return dimpos.getBlockPos().offset(machineSide);
+    }
+
+    @Override
+    public int getConnectedDimensionId(EnumFacing side) {
+        DimensionBlockPos dimpos = WorldSavedDataMachines.INSTANCE.machinePositions.get(StructureTools.getCoordsForPos(this.getPos()));
+        if(dimpos == null) {
+            return 0;
+        }
+
+        return dimpos.getDimension();
+    }
 
     @Override
     public boolean hasCapability(Capability<?> capability, EnumFacing facing) {