Add redstone relay block

 - Move redstone methods out of the IAPIEnvironment, and into a new
   RedstoneAccess. We similarly move the implementation from Environment
   into a new RedstoneState class.

   The interface is possibly a little redundant (interfaces with a
   single implementation are always a little suspect), but it's nice to
   keep the consumer/producer interfaces separate.

 - Abstract most redstone API methods into a separate shared class, that
   can be used by both the rs API and the new redstone relay.

 - Add the new redstone relay block.

The docs are probably a little lacking here, but I really struggled to
write anything which wasn't just "look, it's the same as the redstone
API".

doc/events/redstone.md

@@ -8,7 +8,7 @@ SPDX-FileCopyrightText: 2021 The CC: Tweaked Developers
 SPDX-License-Identifier: MPL-2.0
 -->
 
-The [`event!redstone`] event is fired whenever any redstone inputs on the computer change.
+The [`event!redstone`] event is fired whenever any redstone inputs on the computer or [relay][`redstone_relay`] change.
 
 ## Return values
 1. [`string`]: The event name.
@@ -21,3 +21,7 @@ while true do
   print("A redstone input has changed!")
 end
 ```
+
+## See also
+ - [The `redstone` API on computers][`module!redstone`]
+ - [The `redstone_relay` peripheral][`redstone_relay`]

gradle/libs.versions.toml

@@ -56,7 +56,7 @@ junit = "5.10.1"
 jmh = "1.37"
 
 # Build tools
-cctJavadoc = "1.8.2"
+cctJavadoc = "1.8.3"
 checkstyle = "10.14.1"
 curseForgeGradle = "1.0.14"
 errorProne-core = "2.27.0"

projects/common/src/main/java/dan200/computercraft/data/BlockModelProvider.java

@@ -97,6 +97,8 @@ public static void addBlockModels(BlockModelGenerators generators) {
 
         registerCable(generators);
 
+        registerRedstoneControl(generators);
+
         registerTurtleUpgrade(generators, "block/turtle_crafting_table", "block/turtle_crafty_face");
         registerTurtleUpgrade(generators, "block/turtle_speaker", "block/turtle_speaker_face");
         registerTurtleModem(generators, "block/turtle_modem_normal", "block/wireless_modem_normal_face");
@@ -355,6 +357,18 @@ private static void registerCable(BlockModelGenerators generators) {
         generators.blockStateOutput.accept(generator);
     }
 
+    private static void registerRedstoneControl(BlockModelGenerators generators) {
+        var redstoneControl = ModRegistry.Blocks.REDSTONE_RELAY.get();
+        var model = ModelTemplates.CUBE_ORIENTABLE_TOP_BOTTOM.create(
+            redstoneControl, TextureMapping.orientableCube(redstoneControl), generators.modelOutput
+        );
+        generators.blockStateOutput.accept(
+            MultiVariantGenerator.multiVariant(redstoneControl, Variant.variant().with(VariantProperties.MODEL, model))
+                .with(createHorizontalFacingDispatch())
+        );
+    }
+
+
     private static final BooleanProperty[] CABLE_DIRECTIONS = { CableBlock.DOWN, CableBlock.UP, CableBlock.NORTH, CableBlock.SOUTH, CableBlock.WEST, CableBlock.EAST };
     private static final boolean[] BOOLEANS = new boolean[]{ false, true };
 

projects/common/src/main/java/dan200/computercraft/data/LanguageProvider.java

@@ -80,6 +80,7 @@ private void addTranslations() {
         add(ModRegistry.Items.WIRED_MODEM.get(), "Wired Modem");
         add(ModRegistry.Items.CABLE.get(), "Networking Cable");
         add(ModRegistry.Items.WIRED_MODEM_FULL.get(), "Wired Modem");
+        add(ModRegistry.Items.REDSTONE_RELAY.get(), "Redstone Relay");
 
         add(ModRegistry.Items.TURTLE_NORMAL.get(), "Turtle");
         add(ModRegistry.Blocks.TURTLE_NORMAL.get().getDescriptionId() + ".upgraded", "%s Turtle");

projects/common/src/main/java/dan200/computercraft/data/LootTableProvider.java

@@ -51,6 +51,7 @@ private static void registerBlocks(BiConsumer<ResourceLocation, LootTable.Builde
         selfDrop(add, ModRegistry.Blocks.WIRED_MODEM_FULL);
         selfDrop(add, ModRegistry.Blocks.WIRELESS_MODEM_NORMAL);
         selfDrop(add, ModRegistry.Blocks.WIRELESS_MODEM_ADVANCED);
+        selfDrop(add, ModRegistry.Blocks.REDSTONE_RELAY);
 
         computerDrop(add, ModRegistry.Blocks.COMPUTER_NORMAL);
         computerDrop(add, ModRegistry.Blocks.COMPUTER_ADVANCED);

projects/common/src/main/java/dan200/computercraft/data/RecipeProvider.java

@@ -461,6 +461,17 @@ private void basicRecipes(Consumer<FinishedRecipe> add) {
             .requires(ingredients.string())
             .unlockedBy("has_printer", inventoryChange(ModRegistry.Blocks.PRINTER.get()))
             .save(RecipeWrapper.wrap(ModRegistry.RecipeSerializers.IMPOSTOR_SHAPELESS.get(), add));
+
+        ShapedRecipeBuilder
+            .shaped(RecipeCategory.REDSTONE, ModRegistry.Blocks.REDSTONE_RELAY.get())
+            .pattern("SRS")
+            .pattern("RCR")
+            .pattern("SRS")
+            .define('S', Items.STONE)
+            .define('R', ingredients.redstone())
+            .define('C', ModRegistry.Blocks.CABLE.get())
+            .unlockedBy("has_cable", inventoryChange(ModRegistry.Blocks.CABLE.get()))
+            .save(add);
     }
 
     private static DyeColor ofColour(Colour colour) {

projects/common/src/main/java/dan200/computercraft/data/TagProvider.java

@@ -78,9 +78,12 @@ public static void blockTags(TagConsumer<Block> tags) {
             ModRegistry.Blocks.WIRELESS_MODEM_NORMAL.get(),
             ModRegistry.Blocks.WIRELESS_MODEM_ADVANCED.get(),
             ModRegistry.Blocks.WIRED_MODEM_FULL.get(),
-            ModRegistry.Blocks.CABLE.get()
+            ModRegistry.Blocks.CABLE.get(),
+            ModRegistry.Blocks.REDSTONE_RELAY.get()
         );
 
+        tags.tag(BlockTags.MINEABLE_WITH_AXE).add(ModRegistry.Blocks.LECTERN.get());
+
         tags.tag(BlockTags.WITHER_IMMUNE).add(ModRegistry.Blocks.COMPUTER_COMMAND.get());
 
         tags.tag(ExternalModTags.Blocks.CREATE_BRITTLE).add(

projects/common/src/main/java/dan200/computercraft/shared/ModRegistry.java

@@ -62,6 +62,8 @@
 import dan200.computercraft.shared.peripheral.printer.PrinterBlock;
 import dan200.computercraft.shared.peripheral.printer.PrinterBlockEntity;
 import dan200.computercraft.shared.peripheral.printer.PrinterMenu;
+import dan200.computercraft.shared.peripheral.redstone.RedstoneRelayBlock;
+import dan200.computercraft.shared.peripheral.redstone.RedstoneRelayBlockEntity;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerBlock;
 import dan200.computercraft.shared.peripheral.speaker.SpeakerBlockEntity;
 import dan200.computercraft.shared.platform.PlatformHelper;
@@ -132,7 +134,7 @@ private static BlockBehaviour.Properties properties() {
             return BlockBehaviour.Properties.of().strength(2);
         }
 
-        private static BlockBehaviour.Properties computerProperties() {
+        private static BlockBehaviour.Properties redstoneConductor() {
             // Computers shouldn't conduct redstone through them, so set isRedstoneConductor to false. This still allows
             // redstone to connect to computers though as it's a signal source.
             return properties().isRedstoneConductor((block, level, blockPos) -> false);
@@ -147,11 +149,11 @@ private static BlockBehaviour.Properties modemProperties() {
         }
 
         public static final RegistryEntry<ComputerBlock<ComputerBlockEntity>> COMPUTER_NORMAL = REGISTRY.register("computer_normal",
-            () -> new ComputerBlock<>(computerProperties().mapColor(MapColor.STONE), BlockEntities.COMPUTER_NORMAL));
+            () -> new ComputerBlock<>(redstoneConductor().mapColor(MapColor.STONE), BlockEntities.COMPUTER_NORMAL));
         public static final RegistryEntry<ComputerBlock<ComputerBlockEntity>> COMPUTER_ADVANCED = REGISTRY.register("computer_advanced",
-            () -> new ComputerBlock<>(computerProperties().mapColor(MapColor.GOLD), BlockEntities.COMPUTER_ADVANCED));
+            () -> new ComputerBlock<>(redstoneConductor().mapColor(MapColor.GOLD), BlockEntities.COMPUTER_ADVANCED));
         public static final RegistryEntry<ComputerBlock<ComputerBlockEntity>> COMPUTER_COMMAND = REGISTRY.register("computer_command",
-            () -> new CommandComputerBlock<>(computerProperties().strength(-1, 6000000.0F), BlockEntities.COMPUTER_COMMAND));
+            () -> new CommandComputerBlock<>(redstoneConductor().strength(-1, 6000000.0F), BlockEntities.COMPUTER_COMMAND));
 
         public static final RegistryEntry<TurtleBlock> TURTLE_NORMAL = REGISTRY.register("turtle_normal",
             () -> new TurtleBlock(turtleProperties().mapColor(MapColor.STONE), BlockEntities.TURTLE_NORMAL));
@@ -179,6 +181,9 @@ private static BlockBehaviour.Properties modemProperties() {
         public static final RegistryEntry<CustomLecternBlock> LECTERN = REGISTRY.register("lectern", () -> new CustomLecternBlock(
             BlockBehaviour.Properties.of().mapColor(MapColor.WOOD).instrument(NoteBlockInstrument.BASS).strength(2.5F).sound(SoundType.WOOD).ignitedByLava()
         ));
+
+        public static final RegistryEntry<RedstoneRelayBlock> REDSTONE_RELAY = REGISTRY.register("redstone_relay",
+            () -> new RedstoneRelayBlock(redstoneConductor().mapColor(MapColor.STONE)));
     }
 
     public static class BlockEntities {
@@ -222,6 +227,8 @@ private static <T extends BlockEntity> RegistryEntry<BlockEntityType<T>> ofBlock
             ofBlock(Blocks.WIRELESS_MODEM_ADVANCED, (p, s) -> new WirelessModemBlockEntity(BlockEntities.WIRELESS_MODEM_ADVANCED.get(), p, s, true));
 
         public static final RegistryEntry<BlockEntityType<CustomLecternBlockEntity>> LECTERN = ofBlock(Blocks.LECTERN, CustomLecternBlockEntity::new);
+
+        public static final RegistryEntry<BlockEntityType<RedstoneRelayBlockEntity>> REDSTONE_RELAY = ofBlock(Blocks.REDSTONE_RELAY, RedstoneRelayBlockEntity::new);
     }
 
     public static final class Items {
@@ -267,6 +274,7 @@ private static <B extends Block, I extends Item> RegistryEntry<I> ofBlock(Regist
         public static final RegistryEntry<BlockItem> WIRELESS_MODEM_NORMAL = ofBlock(Blocks.WIRELESS_MODEM_NORMAL, BlockItem::new);
         public static final RegistryEntry<BlockItem> WIRELESS_MODEM_ADVANCED = ofBlock(Blocks.WIRELESS_MODEM_ADVANCED, BlockItem::new);
         public static final RegistryEntry<BlockItem> WIRED_MODEM_FULL = ofBlock(Blocks.WIRED_MODEM_FULL, BlockItem::new);
+        public static final RegistryEntry<BlockItem> REDSTONE_RELAY = ofBlock(Blocks.REDSTONE_RELAY, BlockItem::new);
 
         public static final RegistryEntry<CableBlockItem.Cable> CABLE = REGISTRY.register("cable",
             () -> new CableBlockItem.Cable(Blocks.CABLE.get(), properties()));
@@ -415,6 +423,7 @@ static class CreativeTabs {
                 out.accept(Items.CABLE.get());
                 out.accept(Items.WIRED_MODEM.get());
                 out.accept(Items.WIRED_MODEM_FULL.get());
+                out.accept(Items.REDSTONE_RELAY.get());
 
                 out.accept(Items.MONITOR_NORMAL.get());
                 out.accept(Items.MONITOR_ADVANCED.get());

projects/common/src/main/java/dan200/computercraft/shared/computer/blocks/AbstractComputerBlockEntity.java

@@ -127,7 +127,7 @@ protected void serverTick() {
         // Update the block state if needed.
         updateBlockState(computer.getState());
 
-        var changes = computer.pollAndResetChanges();
+        var changes = computer.pollRedstoneChanges();
         if (changes != 0) {
             for (var direction : DirectionUtil.FACINGS) {
                 if ((changes & (1 << remapToLocalSide(direction).ordinal())) != 0) updateRedstoneTo(direction);
@@ -195,8 +195,10 @@ private void updateRedstoneInput(ServerComputer computer, Direction dir, BlockPo
         var offsetSide = dir.getOpposite();
         var localDir = remapToLocalSide(dir);
 
-        computer.setRedstoneInput(localDir, RedstoneUtil.getRedstoneInput(getLevel(), targetPos, dir));
-        computer.setBundledRedstoneInput(localDir, BundledRedstone.getOutput(getLevel(), targetPos, offsetSide));
+        computer.setRedstoneInput(localDir,
+            RedstoneUtil.getRedstoneInput(getLevel(), targetPos, dir),
+            BundledRedstone.getOutput(getLevel(), targetPos, offsetSide)
+        );
     }
 
     /**

projects/common/src/main/java/dan200/computercraft/shared/computer/core/ServerComputer.java

@@ -134,8 +134,8 @@ boolean hasTimedOut() {
      *
      * @return What sides on the computer have changed.
      */
-    public int pollAndResetChanges() {
-        return computer.pollAndResetChanges();
+    public int pollRedstoneChanges() {
+        return computer.pollRedstoneChanges();
     }
 
     public UUID register() {
@@ -222,19 +222,15 @@ public void queueEvent(String event, @Nullable Object[] arguments) {
     }
 
     public int getRedstoneOutput(ComputerSide side) {
-        return computer.getEnvironment().getExternalRedstoneOutput(side);
+        return computer.isOn() ? computer.getRedstone().getExternalOutput(side) : 0;
     }
 
-    public void setRedstoneInput(ComputerSide side, int level) {
-        computer.getEnvironment().setRedstoneInput(side, level);
+    public void setRedstoneInput(ComputerSide side, int level, int bundledState) {
+        computer.getRedstone().setInput(side, level, bundledState);
     }
 
     public int getBundledRedstoneOutput(ComputerSide side) {
-        return computer.getEnvironment().getExternalBundledRedstoneOutput(side);
-    }
-
-    public void setBundledRedstoneInput(ComputerSide side, int combination) {
-        computer.getEnvironment().setBundledRedstoneInput(side, combination);
+        return computer.isOn() ? computer.getRedstone().getExternalBundledOutput(side) : 0;
     }
 
     public void setPeripheral(ComputerSide side, @Nullable IPeripheral peripheral) {

projects/common/src/main/java/dan200/computercraft/shared/peripheral/redstone/RedstoneRelayBlock.java

@@ -0,0 +1,84 @@
+// SPDX-FileCopyrightText: 2024 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+package dan200.computercraft.shared.peripheral.redstone;
+
+import dan200.computercraft.shared.common.IBundledRedstoneBlock;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.server.level.ServerLevel;
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.item.context.BlockPlaceContext;
+import net.minecraft.world.level.BlockGetter;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.Block;
+import net.minecraft.world.level.block.EntityBlock;
+import net.minecraft.world.level.block.HorizontalDirectionalBlock;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.block.state.StateDefinition;
+
+import javax.annotation.Nonnull;
+
+/**
+ * The block for redstone relays. This mostly just forwards method calls to the {@linkplain RedstoneRelayBlockEntity
+ * block entity}.
+ */
+public final class RedstoneRelayBlock extends HorizontalDirectionalBlock implements EntityBlock, IBundledRedstoneBlock {
+    public RedstoneRelayBlock(Properties properties) {
+        super(properties);
+        registerDefaultState(defaultBlockState().setValue(FACING, Direction.NORTH));
+    }
+
+    @Override
+    protected void createBlockStateDefinition(StateDefinition.Builder<Block, BlockState> properties) {
+        properties.add(FACING);
+    }
+
+    @Override
+    public BlockState getStateForPlacement(BlockPlaceContext placement) {
+        return defaultBlockState().setValue(FACING, placement.getHorizontalDirection());
+    }
+
+    @Override
+    @Deprecated
+    public void tick(BlockState state, ServerLevel level, BlockPos pos, RandomSource random) {
+        super.tick(state, level, pos, random);
+
+        if (level.getBlockEntity(pos) instanceof RedstoneRelayBlockEntity relay) relay.update();
+    }
+
+    @Override
+    @Deprecated
+    public boolean isSignalSource(@Nonnull BlockState state) {
+        return true;
+    }
+
+    @Override
+    @Deprecated
+    public int getDirectSignal(@Nonnull BlockState state, BlockGetter level, @Nonnull BlockPos pos, @Nonnull Direction incomingSide) {
+        return level.getBlockEntity(pos) instanceof RedstoneRelayBlockEntity relay ? relay.getRedstoneOutput(incomingSide.getOpposite()) : 0;
+    }
+
+    @Override
+    @Deprecated
+    public int getSignal(BlockState state, BlockGetter level, BlockPos pos, Direction direction) {
+        return getDirectSignal(state, level, pos, direction);
+    }
+
+    @Override
+    public int getBundledRedstoneOutput(Level level, BlockPos pos, Direction side) {
+        return level.getBlockEntity(pos) instanceof RedstoneRelayBlockEntity relay ? relay.getBundledRedstoneOutput(side) : 0;
+    }
+
+    @Override
+    @Deprecated
+    public void neighborChanged(@Nonnull BlockState state, @Nonnull Level world, @Nonnull BlockPos pos, @Nonnull Block neighbourBlock, @Nonnull BlockPos neighbourPos, boolean isMoving) {
+        if (world.getBlockEntity(pos) instanceof RedstoneRelayBlockEntity relay) relay.neighborChanged(neighbourPos);
+    }
+
+    @Override
+    public BlockEntity newBlockEntity(BlockPos pos, BlockState state) {
+        return new RedstoneRelayBlockEntity(pos, state);
+    }
+}