implement debuff system; add DebuffEffect interface and apply slow de…

…buff in lion-prey interaction

games/hungry-lion/GENAICODE_INSTRUCTIONS.md

@@ -237,4 +237,22 @@ When implementing ambush state and mechanics:
    - Balance risk/reward of ambush state
    - Consider prey behavior modifications
 
-Remember: Documentation is as important as code. Every code change should be reflected in the project's documentation to maintain clarity and facilitate future development.
+Remember: Documentation is as important as code. Every code change should be reflected in the project's documentation to maintain clarity and facilitate future development.
+### Debuff Mechanics Pattern
+When implementing temporary effects on entities (debuffs):
+
+1. Debuff Definition:
+   - Use the `DebuffEffect` interface to define temporary effects
+   - Include start time and duration properties
+   - Consider the effect type and strength
+
+2. Application Guidelines:
+   - Apply debuffs through interaction definitions
+   - Set appropriate duration based on game balance
+   - Consider frame-rate independence for timing
+
+3. Processing and Cleanup:
+   - Check and process debuffs in entity update
+   - Apply effects consistently across all entity types
+   - Automatically clear expired debuffs
+   - Reset affected properties when debuff expires

games/hungry-lion/GENAICODE_TRACKER.md

@@ -103,6 +103,11 @@
             *   ✅ Implemented health reduction when touched by lion
             *   ✅ Added force application towards lion
             *   ✅ Implemented conversion to carrion when health reaches 0
+            *   ✅ Implemented Debuff System
+                *   ✅ Added generic DebuffEffect interface
+                *   ✅ Implemented velocity reduction during debuff
+                *   ✅ Added debuff application in lion-prey interaction
+                *   ✅ Added automatic debuff cleanup
         *   ✅ Natural Prey Movement Behavior
             *   ✅ Added idle states where prey sometimes stand still
             *   ✅ Implemented social behaviors where prey sometimes follow others

games/hungry-lion/src/screens/play/game-world/entities/entities-types.ts

@@ -16,6 +16,12 @@ export interface Entity {
   forces: Vector2D[];
   velocity: Vector2D;
   stateMachine?: [StateType, StateData];
+  debuff?: DebuffEffect;
+}
+
+export interface DebuffEffect {
+  startTime: number;
+  duration: number;
 }
 
 export interface LionEntity extends Entity {
@@ -54,4 +60,4 @@ export interface CarrionEntity extends Entity {
 export type Entities = {
   entities: Map<EntityId, Entity>;
   nextEntityId: EntityId;
-};
+};

games/hungry-lion/src/screens/play/game-world/entities/entity-update.ts

@@ -17,6 +17,16 @@ export function entityUpdate(entity: Entity, updateContext: UpdateContext) {
   );
   entity.forces.push(accelerationForce);
 
+  // Handle debuff effect
+  if (entity.debuff) {
+    const debuffElapsed = updateContext.gameState.time - entity.debuff.startTime;
+    if (debuffElapsed < entity.debuff.duration) {
+      entity.velocity = vectorScale(entity.velocity, 0.5); // Reduce velocity by 50% while debuffed
+    } else {
+      entity.debuff = undefined; // Clear expired debuff
+    }
+  }
+
   entity.velocity = vectorAdd(entity.velocity, entity.forces.reduce(vectorAdd, { x: 0, y: 0 }));
   // TODO: Introduce angular velocity
   entity.direction = entity.targetDirection;

games/hungry-lion/src/screens/play/game-world/interactions/definitions/lion-prey-interaction.ts

@@ -18,12 +18,18 @@ export const LION_PREY_INTERACTION: InteractionDefinition = {
     return distance < 30; // Same as maxDistance for consistency
   },
 
-  perform: (source, target) => {
+  perform: (source, target, updateContext) => {
     const prey = target as PreyEntity;
 
     // Reduce prey health
     prey.health = Math.max(prey.health - HEALTH_DECREMENT, 0);
 
+    // Apply slow debuff
+    prey.debuff = {
+      startTime: updateContext.gameState.time,
+      duration: 500, // 500ms slow duration
+    };
+
     // Apply force towards lion
     const direction = vectorNormalize(vectorSubtract(source.position, prey.position));
     const force = vectorScale(direction, FORCE_STRENGTH);