Display Arm Interaction Points

- placed mechanical arms will show their in/out puts if you look at them while holding a wrench

src/main/java/com/simibubi/create/content/logistics/block/mechanicalArm/ArmInteractionPointHandler.java

@@ -6,6 +6,7 @@ import java.util.Map;
 import java.util.Map.Entry;
 
 import com.simibubi.create.AllBlocks;
+import com.simibubi.create.AllItems;
 import com.simibubi.create.CreateClient;
 import com.simibubi.create.content.logistics.block.mechanicalArm.ArmInteractionPoint.Mode;
 import com.simibubi.create.foundation.networking.AllPackets;
@@ -14,11 +15,15 @@ import net.minecraft.block.BlockState;
 import net.minecraft.client.Minecraft;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.item.ItemStack;
+import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.ActionResultType;
 import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.BlockRayTraceResult;
+import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.util.math.shapes.VoxelShape;
 import net.minecraft.world.World;
 import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.client.event.RenderWorldLastEvent;
 import net.minecraftforge.event.entity.player.PlayerInteractEvent;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.common.Mod.EventBusSubscriber;
@@ -29,6 +34,8 @@ public class ArmInteractionPointHandler {
 	static Map<BlockPos, ArmInteractionPoint> currentSelection = new HashMap<>();
 	static ItemStack currentItem;
 
+	static long lastBlockPos = -1;
+
 	@SubscribeEvent
 	public static void rightClickingBlocksSelectsThem(PlayerInteractEvent.RightClickBlock event) {
 		if (currentItem == null)
@@ -74,21 +81,61 @@ public class ArmInteractionPointHandler {
 
 	public static void tick() {
 		PlayerEntity player = Minecraft.getInstance().player;
-		World world = Minecraft.getInstance().world;
+
 		if (player == null)
 			return;
 
 		ItemStack heldItemMainhand = player.getHeldItemMainhand();
 		if (!AllBlocks.MECHANICAL_ARM.isIn(heldItemMainhand)) {
 			currentItem = null;
-			return;
+		} else {
-		}
 			if (heldItemMainhand != currentItem) {
 				currentSelection.clear();
 				currentItem = heldItemMainhand;
 			}
 
-		for (Iterator<Entry<BlockPos, ArmInteractionPoint>> iterator = currentSelection.entrySet()
+			drawOutlines(currentSelection);
+		}
+
+		checkForWrench(heldItemMainhand);
+	}
+
+	private static void checkForWrench(ItemStack heldItem) {
+		if(!AllItems.WRENCH.isIn(heldItem)) {
+			return;
+		}
+
+		RayTraceResult objectMouseOver = Minecraft.getInstance().objectMouseOver;
+		if (!(objectMouseOver instanceof BlockRayTraceResult)) {
+			return;
+		}
+
+		BlockRayTraceResult result = (BlockRayTraceResult) objectMouseOver;
+		BlockPos pos = result.getPos();
+
+		TileEntity te = Minecraft.getInstance().world.getTileEntity(pos);
+		if (!(te instanceof ArmTileEntity)) {
+			lastBlockPos = -1;
+			currentSelection.clear();
+			return;
+		}
+
+		if (lastBlockPos == -1 || lastBlockPos != pos.toLong()) {
+			currentSelection.clear();
+			ArmTileEntity arm = (ArmTileEntity) te;
+			arm.inputs.forEach(point -> currentSelection.put(point.pos, point));
+			arm.outputs.forEach(point -> currentSelection.put(point.pos, point));
+			lastBlockPos = pos.toLong();
+		}
+
+		if (lastBlockPos != -1) {
+			drawOutlines(currentSelection);
+		}
+	}
+
+	private static void drawOutlines(Map<BlockPos, ArmInteractionPoint> selection) {
+		World world = Minecraft.getInstance().world;
+		for (Iterator<Entry<BlockPos, ArmInteractionPoint>> iterator = selection.entrySet()
 			.iterator(); iterator.hasNext();) {
 			Entry<BlockPos, ArmInteractionPoint> entry = iterator.next();
 			BlockPos pos = entry.getKey();