Basic NFC Modem functionality for Pocket Computer

projects/common-api/src/main/java/dan200/computercraft/api/ComputerCraftAPI.java

@@ -22,6 +22,7 @@
 import net.minecraft.core.BlockPos;
 import net.minecraft.core.Direction;
 import net.minecraft.server.MinecraftServer;
+import net.minecraft.world.entity.Entity;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
 
@@ -161,6 +162,17 @@ public static PacketNetwork getWirelessNetwork(MinecraftServer server) {
         return getInstance().getWirelessNetwork(server);
     }
 
+    /**
+     * Attempt to get the NFC network for a player.
+     *
+     * @param server The current Minecraft server.
+     * @param entity The entity whose NFC network should be obtained.
+     * @return The NFC network, or {@code null} if it could not be fetched.
+     */
+    public static PacketNetwork getNfcNetwork(MinecraftServer server, Entity entity) {
+        return getInstance().getNfcNetwork(server, entity);
+    }
+
     /**
      * Register a custom {@link ILuaAPI}, which may be added onto all computers without requiring a peripheral.
      * <p>

projects/common-api/src/main/java/dan200/computercraft/api/network/PacketNetwork.java

@@ -53,4 +53,19 @@ public interface PacketNetwork {
      * @see PacketReceiver#receiveDifferentDimension(Packet)
      */
     void transmitInterdimensional(Packet packet);
+
+    static void tryTransmit(PacketReceiver receiver, Packet packet, double range, boolean interdimensional) {
+        var sender = packet.sender();
+        if (receiver.getLevel() == sender.getLevel()) {
+            var receiveRange = Math.max(range, receiver.getRange()); // Ensure range is symmetrical
+            var distanceSq = receiver.getPosition().distanceToSqr(sender.getPosition());
+            if (interdimensional || receiver.isInterdimensional() || distanceSq <= receiveRange * receiveRange) {
+                receiver.receiveSameDimension(packet, Math.sqrt(distanceSq));
+            }
+        } else {
+            if (interdimensional || receiver.isInterdimensional()) {
+                receiver.receiveDifferentDimension(packet);
+            }
+        }
+    }
 }

projects/common-api/src/main/java/dan200/computercraft/api/pocket/IPocketAccess.java

@@ -47,22 +47,40 @@ public interface IPocketAccess {
     void setColour(int colour);
 
     /**
-     * Get the colour of this pocket computer's light as a RGB number.
+     * Get the primary colour of this pocket computer's light as a RGB number.
      *
-     * @return The colour this light is. This will be a RGB colour between {@code 0x000000} and {@code 0xFFFFFF} or
+     * @return The primary colour this light is. This will be a RGB colour between {@code 0x000000} and {@code 0xFFFFFF} or
      * -1 if it has no colour.
-     * @see #setLight(int)
+     * @see #setLightPrimary(int)
      */
-    int getLight();
+    int getLightPrimary();
 
     /**
-     * Set the colour of the pocket computer's light to a RGB number.
+     * Set the primary colour of the pocket computer's light to a RGB number.
      *
-     * @param colour The colour this modem's light will be changed to. This should be a RGB colour between
+     * @param colour The primary colour this modem's light will be changed to. This should be a RGB colour between
      *               {@code 0x000000} and {@code 0xFFFFFF} or -1 to reset to the default colour.
-     * @see #getLight()
+     * @see #getLightPrimary()
      */
-    void setLight(int colour);
+    void setLightPrimary(int colour);
+
+    /**
+     * Get the secondary colour of this pocket computer's light as a RGB number.
+     *
+     * @return The secondary colour this light is. This will be a RGB colour between {@code 0x000000} and {@code 0xFFFFFF} or
+     * -1 if it has no colour.
+     * @see #setLightSecondary(int)
+     */
+    int getLightSecondary();
+
+    /**
+     * Set the secondary colour of the pocket computer's light to a RGB number.
+     *
+     * @param colour The secondary colour this modem's light will be changed to. This should be a RGB colour between
+     *               {@code 0x000000} and {@code 0xFFFFFF} or -1 to reset to the default colour.
+     * @see #getLightSecondary()
+     */
+    void setLightSecondary(int colour);
 
     /**
      * Get the upgrade-specific NBT.

projects/common-api/src/main/java/dan200/computercraft/impl/ComputerCraftAPIService.java

@@ -24,6 +24,7 @@
 import net.minecraft.core.Registry;
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.server.MinecraftServer;
+import net.minecraft.world.entity.Entity;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
 import org.jetbrains.annotations.ApiStatus;
@@ -61,6 +62,8 @@ static ComputerCraftAPIService get() {
 
     PacketNetwork getWirelessNetwork(MinecraftServer server);
 
+    PacketNetwork getNfcNetwork(MinecraftServer server, Entity entity);
+
     void registerAPIFactory(ILuaAPIFactory factory);
 
     WiredNode createWiredNodeForElement(WiredElement element);

projects/common/src/client/java/dan200/computercraft/client/FrameInfo.java

@@ -24,6 +24,10 @@ public static long getRenderFrame() {
         return renderFrame;
     }
 
+    public static int getTick() {
+        return tick;
+    }
+
     public static void onTick() {
         tick++;
     }

projects/common/src/client/java/dan200/computercraft/client/platform/ClientNetworkContextImpl.java

@@ -67,9 +67,9 @@ public void handlePlayRecord(BlockPos pos, @Nullable SoundEvent sound, @Nullable
     }
 
     @Override
-    public void handlePocketComputerData(int instanceId, ComputerState state, int lightState, TerminalState terminal) {
+    public void handlePocketComputerData(int instanceId, ComputerState state, int primaryLightState, int secondaryLightState, TerminalState terminal) {
         var computer = ClientPocketComputers.get(instanceId, terminal.colour);
-        computer.setState(state, lightState);
+        computer.setState(state, primaryLightState, secondaryLightState);
         if (terminal.hasTerminal()) computer.setTerminal(terminal);
     }
 

projects/common/src/client/java/dan200/computercraft/client/pocket/PocketComputerData.java

@@ -4,6 +4,7 @@
 
 package dan200.computercraft.client.pocket;
 
+import dan200.computercraft.client.FrameInfo;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.computer.core.ComputerState;
 import dan200.computercraft.shared.computer.terminal.NetworkedTerminal;
@@ -24,14 +25,42 @@
 public class PocketComputerData {
     private final NetworkedTerminal terminal;
     private ComputerState state = ComputerState.OFF;
-    private int lightColour = -1;
+    private int primaryLightColour = -1;
+    private int secondaryLightColour = -1;
 
     public PocketComputerData(boolean colour) {
         terminal = new NetworkedTerminal(Config.pocketTermWidth, Config.pocketTermHeight, colour);
     }
 
     public int getLightState() {
-        return state != ComputerState.OFF ? lightColour : -1;
+        if (state != ComputerState.OFF) {
+            if (secondaryLightColour == -1) {
+                return primaryLightColour;
+            } else if (primaryLightColour == -1) {
+                return secondaryLightColour;
+            } else {
+                double weight = (Math.sin(((double)(FrameInfo.getTick() % 41) / 40) * Math.PI * 2) + 1) / 2;
+                return blend(primaryLightColour, secondaryLightColour, weight);
+            }
+        }
+        return -1;
+    }
+
+    private static int blend(int a, int b, double weight) {
+        int[][] rgb = {
+            { a >> 16, b >> 16 },
+            { (a & 0x00ff00) >> 8, (b & 0x00ff00) >> 8 },
+            { a & 0x0000ff, b & 0x0000ff },
+        };
+        int[] channels = new int[3];
+        for (int i = 0; i < 3; i++) {
+            channels[i] = (int)Math.sqrt(Math.pow(rgb[i][0], 2) * weight + Math.pow(rgb[i][1], 2) * (1 - weight));
+        }
+        int color = 0;
+        for (int channel : channels) {
+            color = (color << 8) + channel;
+        }
+        return color;
     }
 
     public Terminal getTerminal() {
@@ -42,9 +71,10 @@ public ComputerState getState() {
         return state;
     }
 
-    public void setState(ComputerState state, int lightColour) {
+    public void setState(ComputerState state, int primaryLightColour, int secondaryLightColor) {
         this.state = state;
-        this.lightColour = lightColour;
+        this.primaryLightColour = primaryLightColour;
+        this.secondaryLightColour = secondaryLightColor;
     }
 
     public void setTerminal(TerminalState state) {

projects/common/src/main/java/dan200/computercraft/impl/AbstractComputerCraftAPI.java

@@ -32,6 +32,7 @@
 import net.minecraft.resources.ResourceKey;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.server.MinecraftServer;
+import net.minecraft.world.entity.Entity;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.level.Level;
 
@@ -100,6 +101,11 @@ public final PacketNetwork getWirelessNetwork(MinecraftServer server) {
         return ServerContext.get(server).wirelessNetwork();
     }
 
+    @Override
+    public final PacketNetwork getNfcNetwork(MinecraftServer server, Entity entity) {
+        return ServerContext.get(server).nfcNetwork(entity);
+    }
+
     @Override
     public final void registerAPIFactory(ILuaAPIFactory factory) {
         ApiFactories.register(factory);

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

@@ -22,10 +22,12 @@
 import dan200.computercraft.shared.CommonHooks;
 import dan200.computercraft.shared.computer.metrics.GlobalMetrics;
 import dan200.computercraft.shared.config.ConfigSpec;
+import dan200.computercraft.shared.peripheral.modem.wireless.NFCNetworkManager;
 import dan200.computercraft.shared.peripheral.modem.wireless.WirelessNetwork;
 import dan200.computercraft.shared.util.IDAssigner;
 import net.minecraft.SharedConstants;
 import net.minecraft.server.MinecraftServer;
+import net.minecraft.world.entity.Entity;
 import net.minecraft.world.level.storage.LevelResource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -64,6 +66,7 @@ public final class ServerContext {
     private final MainThread mainThread;
     private final IDAssigner idAssigner;
     private final WirelessNetwork wirelessNetwork = new WirelessNetwork();
+    private final NFCNetworkManager nfcNetworkManager = new NFCNetworkManager();
     private final Path storageDir;
 
     private ServerContext(MinecraftServer server) {
@@ -209,6 +212,18 @@ public PacketNetwork wirelessNetwork() {
         return wirelessNetwork;
     }
 
+    /**
+     * Get a player's NFC network.
+     * <p>
+     * Use {@link ComputerCraftAPI#getNfcNetwork(MinecraftServer, Entity)} instead of this method.
+     * @param entity The entity whose NFC network should be obtained.
+     * @return The NFC network.
+     */
+    public PacketNetwork nfcNetwork(Entity entity) {
+        PacketNetwork network = nfcNetworkManager.get(entity);
+        return network == null ? nfcNetworkManager.addNetwork(entity) : network;
+    }
+
     private record Environment(MinecraftServer server) implements GlobalEnvironment {
         @Override
         public @Nullable Mount createResourceMount(String domain, String subPath) {

projects/common/src/main/java/dan200/computercraft/shared/network/client/ClientNetworkContext.java

@@ -30,7 +30,7 @@ public interface ClientNetworkContext {
 
     void handlePlayRecord(BlockPos pos, @Nullable SoundEvent sound, @Nullable String name);
 
-    void handlePocketComputerData(int instanceId, ComputerState state, int lightState, TerminalState terminal);
+    void handlePocketComputerData(int instanceId, ComputerState state, int primaryLightColor, int secondaryLightColor, TerminalState terminal);
 
     void handlePocketComputerDeleted(int instanceId);
 

projects/common/src/main/java/dan200/computercraft/shared/network/client/PocketComputerDataMessage.java

@@ -19,34 +19,38 @@
 public class PocketComputerDataMessage implements NetworkMessage<ClientNetworkContext> {
     private final int instanceId;
     private final ComputerState state;
-    private final int lightState;
+    private final int primaryLightState;
+    private final int secondaryLightState;
     private final TerminalState terminal;
 
     public PocketComputerDataMessage(PocketServerComputer computer, boolean sendTerminal) {
         instanceId = computer.getInstanceID();
         state = computer.getState();
-        lightState = computer.getLight();
+        primaryLightState = computer.getLightPrimary();
+        secondaryLightState = computer.getLightSecondary();
         terminal = sendTerminal ? computer.getTerminalState() : new TerminalState((NetworkedTerminal) null);
     }
 
     public PocketComputerDataMessage(FriendlyByteBuf buf) {
         instanceId = buf.readVarInt();
         state = buf.readEnum(ComputerState.class);
-        lightState = buf.readVarInt();
+        primaryLightState = buf.readVarInt();
+        secondaryLightState = buf.readVarInt();
         terminal = new TerminalState(buf);
     }
 
     @Override
     public void write(FriendlyByteBuf buf) {
         buf.writeVarInt(instanceId);
         buf.writeEnum(state);
-        buf.writeVarInt(lightState);
+        buf.writeVarInt(primaryLightState);
+        buf.writeVarInt(secondaryLightState);
         terminal.write(buf);
     }
 
     @Override
     public void handle(ClientNetworkContext context) {
-        context.handlePocketComputerData(instanceId, state, lightState, terminal);
+        context.handlePocketComputerData(instanceId, state, primaryLightState, secondaryLightState, terminal);
     }
 
     @Override

projects/common/src/main/java/dan200/computercraft/shared/peripheral/modem/wireless/NFCNetworkManager.java

@@ -0,0 +1,30 @@
+// SPDX-FileCopyrightText: 2017 The CC: Tweaked Developers
+//
+// SPDX-License-Identifier: MPL-2.0
+
+package dan200.computercraft.shared.peripheral.modem.wireless;
+
+import net.minecraft.world.entity.Entity;
+
+import javax.annotation.Nullable;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+public class NFCNetworkManager {
+    private final Map<Entity, WirelessNetwork> networks = new ConcurrentHashMap<>();
+
+    public WirelessNetwork addNetwork(Entity entity) {
+        if (!networks.containsKey(entity)) {
+            networks.put(entity, new WirelessNetwork(() -> networks.remove(entity)));
+        }
+        return networks.get(entity);
+    }
+
+    public void removeNetwork(Entity entity) {
+        networks.remove(entity);
+    }
+
+    public @Nullable WirelessNetwork get(Entity entity) {
+        return networks.get(entity);
+    }
+}