Implement ultimate selection feature with key binding and UI

src/client/java/com/ottohg/ultcraft/UltcraftClient.java

@@ -38,6 +38,10 @@ public class UltcraftClient implements ClientModInitializer {
 					Ultcraft.LOGGER.info("Ultimate activation requested!");
 				}
 			}
+
+            while (UltimateKeybinding.switchUltimateMenuKey.consumeClick()) {
+                client.setScreen(new com.ottohg.ultcraft.client.UltimateSelectionScreen());
+            }
 		});
 		
 		Ultcraft.LOGGER.info("Ultcraft Client initialized successfully!");

src/client/java/com/ottohg/ultcraft/client/ClientUltimateData.java

@@ -7,8 +7,12 @@ package com.ottohg.ultcraft.client;
 public class ClientUltimateData {
     private static float targetCharge = 0.0f;
     private static float displayedCharge = 0.0f;
+    
+    // Animation state
     private static long lastAnimationTime = 0;
-    private static boolean isAnimatingReset = false;
+    private static boolean isAnimating = false;
+    private static float animationStartCharge = 0.0f;
+    private static float animationTargetCharge = 0.0f;
     private static final float RESET_DURATION = 500.0f; // 0.5 seconds
     
     public static float getCharge() {
@@ -16,17 +20,17 @@ public class ClientUltimateData {
     }
 
     public static float getDisplayCharge() {
-        if (isAnimatingReset) {
+        if (isAnimating) {
             long currentTime = System.currentTimeMillis();
             float timeDelta = currentTime - lastAnimationTime;
             float progress = timeDelta / RESET_DURATION;
             
             if (progress >= 1.0f) {
-                displayedCharge = targetCharge;
+                displayedCharge = animationTargetCharge;
-                isAnimatingReset = false;
+                isAnimating = false;
             } else {
-                // Lerp from 100 to 0
+                // Lerp from start to target
-                displayedCharge = 100.0f * (1.0f - progress);
+                displayedCharge = animationStartCharge + (animationTargetCharge - animationStartCharge) * progress;
             }
         } else {
             displayedCharge = targetCharge;
@@ -37,11 +41,16 @@ public class ClientUltimateData {
     public static void setCharge(float charge) {
         float newCharge = Math.min(charge, 100.0f);
         
-        // Check if we should trigger reset animation (high charge -> low charge)
+        // Check for significant drops that should be animated
-        // Relaxed condition to catch cases where passive charge might have ticked once
+        // 1. Reset: > 90 -> < 10
-        if (targetCharge > 90.0f && newCharge < 10.0f) {
+        // 2. Switch penalty: > 15 -> ~15
-            isAnimatingReset = true;
+        if ((targetCharge > 90.0f && newCharge < 10.0f) || 
+            (targetCharge > 15.1f && Math.abs(newCharge - 15.0f) < 0.1f)) {
+            
+            isAnimating = true;
             lastAnimationTime = System.currentTimeMillis();
+            animationStartCharge = displayedCharge; // Start from current visual position (usually 100 or current)
+            animationTargetCharge = newCharge;
         }
         
         targetCharge = newCharge;

src/client/java/com/ottohg/ultcraft/client/UltimateKeybinding.java

@@ -11,6 +11,7 @@ import org.lwjgl.glfw.GLFW;
  */
 public class UltimateKeybinding {
     public static KeyMapping activateUltimateKey;
+    public static KeyMapping switchUltimateMenuKey;
     public static final KeyMapping.Category ULTIMATE_CATEGORY = KeyMapping.Category.register(Identifier.fromNamespaceAndPath("ultcraft", "ultimate"));
     
     public static void register() {
@@ -20,5 +21,12 @@ public class UltimateKeybinding {
             GLFW.GLFW_KEY_Z, // Default to 'Z' key  
             ULTIMATE_CATEGORY // Category
         ));
+
+        switchUltimateMenuKey = KeyBindingHelper.registerKeyBinding(new KeyMapping(
+            "key.ultcraft.switch_ultimate_menu",
+            InputConstants.Type.KEYSYM,
+            GLFW.GLFW_KEY_H,
+            ULTIMATE_CATEGORY
+        ));
     }
 }

src/client/java/com/ottohg/ultcraft/client/UltimateSelectionScreen.java

@@ -0,0 +1,46 @@
+package com.ottohg.ultcraft.client;
+
+import com.ottohg.ultcraft.UltimateType;
+import com.ottohg.ultcraft.network.UltimateSwitchPacket;
+import net.fabricmc.fabric.api.client.networking.v1.ClientPlayNetworking;
+import net.minecraft.client.gui.GuiGraphics;
+import net.minecraft.client.gui.components.Button;
+import net.minecraft.client.gui.screens.Screen;
+import net.minecraft.network.chat.Component;
+
+public class UltimateSelectionScreen extends Screen {
+    public UltimateSelectionScreen() {
+        super(Component.literal("Select Ultimate"));
+    }
+
+    @Override
+    protected void init() {
+        super.init();
+
+        int centerX = this.width / 2;
+        int centerY = this.height / 2;
+
+        this.addRenderableWidget(Button.builder(UltimateType.ARMED_AND_DANGEROUS.getDisplayName(), button -> {
+            selectUltimate(UltimateType.ARMED_AND_DANGEROUS);
+        })
+        .bounds(centerX - 100, centerY - 25, 200, 20).build());
+
+        this.addRenderableWidget(Button.builder(UltimateType.LIKE_A_RABBIT.getDisplayName(), button -> {
+            selectUltimate(UltimateType.LIKE_A_RABBIT);
+        })
+        .bounds(centerX - 100, centerY + 5, 200, 20).build());
+    }
+
+    private void selectUltimate(UltimateType type) {
+        ClientPlayNetworking.send(new UltimateSwitchPacket(type.getId()));
+        this.onClose();
+    }
+
+    @Override
+    public void render(GuiGraphics guiGraphics, int mouseX, int mouseY, float partialTick) {
+        // Draw semi-transparent background manually to avoid overlapping blur issues
+        guiGraphics.fill(0, 0, this.width, this.height, 0x90000000);
+        guiGraphics.drawCenteredString(this.font, this.title, this.width / 2, this.height / 2 - 50, 0xFFFFFF);
+        super.render(guiGraphics, mouseX, mouseY, partialTick);
+    }
+}

src/main/java/com/ottohg/ultcraft/Ultcraft.java

@@ -1,6 +1,7 @@
 package com.ottohg.ultcraft;
 
 import com.ottohg.ultcraft.network.UltimateActivatePacket;
+import com.ottohg.ultcraft.network.UltimateSwitchPacket;
 import net.fabricmc.api.ModInitializer;
 import net.fabricmc.fabric.api.event.lifecycle.v1.ServerTickEvents;
 import net.fabricmc.fabric.api.networking.v1.PayloadTypeRegistry;
@@ -20,10 +21,12 @@ public class Ultcraft implements ModInitializer {
 		
 		// Register network packets
 		PayloadTypeRegistry.playC2S().register(UltimateActivatePacket.TYPE, UltimateActivatePacket.CODEC);
+		PayloadTypeRegistry.playC2S().register(UltimateSwitchPacket.TYPE, UltimateSwitchPacket.CODEC);
 		PayloadTypeRegistry.playS2C().register(com.ottohg.ultcraft.network.UltimateSyncPacket.TYPE, 
 			com.ottohg.ultcraft.network.UltimateSyncPacket.CODEC);
 		
 		UltimateActivatePacket.register();
+		ServerPlayNetworking.registerGlobalReceiver(UltimateSwitchPacket.TYPE, UltimateSwitchPacket::handle);
 		
 		// Register server tick event for passive charging
 		ServerTickEvents.END_SERVER_TICK.register(server -> {

src/main/java/com/ottohg/ultcraft/UltimateData.java

@@ -21,6 +21,7 @@ import java.util.UUID;
 public class UltimateData {
     private static final Map<UUID, Float> ultimateCharges = new HashMap<>();
     private static final Map<UUID, Long> lastTickTimes = new HashMap<>();
+    private static final Map<UUID, UltimateType> selectedUltimates = new HashMap<>();
     
     // Constants
     private static final float PASSIVE_CHARGE_PER_MINUTE = 100.0f / 15.0f; // 100% over 15 minutes
@@ -77,7 +78,10 @@ public class UltimateData {
             return false;
         }
         
-        // Apply effects: Strength 2 and Regeneration 2 for 5 seconds
+        UltimateType type = getUltimateType(player.getUUID());
+        
+        if (type == UltimateType.ARMED_AND_DANGEROUS) {
+            // Apply effects: Strength 2 and Regeneration 2 for 10 seconds
             Holder<MobEffect> strength = BuiltInRegistries.MOB_EFFECT.wrapAsHolder(
                 BuiltInRegistries.MOB_EFFECT.getValue(Identifier.fromNamespaceAndPath("minecraft", "strength"))
             );
@@ -87,17 +91,52 @@ public class UltimateData {
             
             player.addEffect(new MobEffectInstance(strength, 200, 1));
             player.addEffect(new MobEffectInstance(regeneration, 200, 1));
+        } else if (type == UltimateType.LIKE_A_RABBIT) {
+            // Swiftness 2 and Jump Boost 2 for 15 seconds
+            Holder<MobEffect> speed = BuiltInRegistries.MOB_EFFECT.wrapAsHolder(
+                BuiltInRegistries.MOB_EFFECT.getValue(Identifier.fromNamespaceAndPath("minecraft", "speed"))
+            );
+            Holder<MobEffect> jumpBoost = BuiltInRegistries.MOB_EFFECT.wrapAsHolder(
+                BuiltInRegistries.MOB_EFFECT.getValue(Identifier.fromNamespaceAndPath("minecraft", "jump_boost"))
+            );
+             
+             player.addEffect(new MobEffectInstance(speed, 300, 1));
+             player.addEffect(new MobEffectInstance(jumpBoost, 300, 1));
+        }
         
         // Reset charge
         setCharge(player.getUUID(), 0.0f);
         
-        Ultcraft.LOGGER.info("Player {} activated ultimate!", player.getName().getString());
+        Ultcraft.LOGGER.info("Player {} activated ultimate: {}", player.getName().getString(), type);
         return true;
     }
     
     public static void removePlayer(UUID playerId) {
         ultimateCharges.remove(playerId);
         lastTickTimes.remove(playerId);
+        selectedUltimates.remove(playerId);
+    }
+    
+    public static UltimateType getUltimateType(UUID playerId) {
+        return selectedUltimates.getOrDefault(playerId, UltimateType.ARMED_AND_DANGEROUS);
+    }
+
+    public static void switchUltimate(ServerPlayer player, String ultimateId) {
+        UltimateType newType = UltimateType.fromId(ultimateId);
+        UltimateType currentType = getUltimateType(player.getUUID());
+        
+        if (newType != currentType) {
+            selectedUltimates.put(player.getUUID(), newType);
+            float currentCharge = getCharge(player.getUUID());
+            if (currentCharge > 15.0f) {
+                setCharge(player.getUUID(), 15.0f);
+                // Sync charge immediately
+                ServerPlayNetworking.send(player, new UltimateSyncPacket(15.0f));
+            }
+            // You might want to sync the selected ultimate type to the client here as well, 
+            // but for now, we'll assume the client knows what it selected locally or we rely on charge sync.
+            // If the UI needs to know the server state (e.g. after relog), we'd need another packet.
+        }
     }
 
     public static void saveToNBT(UUID playerId, CompoundTag tag) {

src/main/java/com/ottohg/ultcraft/UltimateType.java

@@ -0,0 +1,33 @@
+package com.ottohg.ultcraft;
+
+import net.minecraft.network.chat.Component;
+
+public enum UltimateType {
+    ARMED_AND_DANGEROUS("Armed and Dangerous", Component.literal("Armed and Dangerous")),
+    LIKE_A_RABBIT("Like a Rabbit", Component.literal("Like a Rabbit"));
+
+    private final String id;
+    private final Component displayName;
+
+    UltimateType(String id, Component displayName) {
+        this.id = id;
+        this.displayName = displayName;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public Component getDisplayName() {
+        return displayName;
+    }
+    
+    public static UltimateType fromId(String id) {
+        for (UltimateType type : values()) {
+            if (type.id.equals(id)) {
+                return type;
+            }
+        }
+        return ARMED_AND_DANGEROUS; // Default
+    }
+}

src/main/java/com/ottohg/ultcraft/network/UltimateSwitchPacket.java

@@ -0,0 +1,30 @@
+package com.ottohg.ultcraft.network;
+
+import com.ottohg.ultcraft.Ultcraft;
+import com.ottohg.ultcraft.UltimateData;
+import io.netty.buffer.ByteBuf;
+import net.minecraft.network.FriendlyByteBuf;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
+import net.minecraft.resources.Identifier;
+
+public record UltimateSwitchPacket(String ultimateId) implements CustomPacketPayload {
+    public static final CustomPacketPayload.Type<UltimateSwitchPacket> TYPE = 
+        new CustomPacketPayload.Type<>(Identifier.fromNamespaceAndPath(Ultcraft.MOD_ID, "switch_ultimate"));
+
+    public static final StreamCodec<FriendlyByteBuf, UltimateSwitchPacket> CODEC = StreamCodec.of(
+        (buf, packet) -> buf.writeUtf(packet.ultimateId),
+        (buf) -> new UltimateSwitchPacket(buf.readUtf())
+    );
+
+    @Override
+    public Type<? extends CustomPacketPayload> type() {
+        return TYPE;
+    }
+    
+    public static void handle(UltimateSwitchPacket packet, net.fabricmc.fabric.api.networking.v1.ServerPlayNetworking.Context context) {
+        context.server().execute(() -> {
+            UltimateData.switchUltimate(context.player(), packet.ultimateId);
+        });
+    }
+}

src/main/resources/assets/ultcraft/lang/en_us.json

@@ -1,4 +1,5 @@
 {
   "key.ultcraft.activate_ultimate": "Activate Ultimate",
+  "key.ultcraft.switch_ultimate_menu": "Switch Ultimate Menu",
   "category.ultcraft.ultimate": "Ultcraft"
 }