PickupItemSystem.java

package com.hypixel.hytale.server.core.modules.entity.item;

import com.hypixel.hytale.component.ArchetypeChunk;
import com.hypixel.hytale.component.CommandBuffer;
import com.hypixel.hytale.component.ComponentType;
import com.hypixel.hytale.component.Ref;
import com.hypixel.hytale.component.RemoveReason;
import com.hypixel.hytale.component.Store;
import com.hypixel.hytale.component.query.Query;
import com.hypixel.hytale.component.system.tick.EntityTickingSystem;
import com.hypixel.hytale.math.vector.Vector3d;
import com.hypixel.hytale.server.core.modules.entity.component.ModelComponent;
import com.hypixel.hytale.server.core.modules.entity.component.TransformComponent;
import com.hypixel.hytale.server.core.universe.world.storage.EntityStore;
import javax.annotation.Nonnull;

public class PickupItemSystem extends EntityTickingSystem<EntityStore> {
   private static final float EYE_HEIGHT_SCALE = 5.0F;
   @Nonnull
   private final ComponentType<EntityStore, PickupItemComponent> pickupItemComponentType;
   @Nonnull
   private final ComponentType<EntityStore, TransformComponent> transformComponentType;
   @Nonnull
   private final Query<EntityStore> query;

   public PickupItemSystem(@Nonnull ComponentType<EntityStore, PickupItemComponent> pickupItemComponentType, @Nonnull ComponentType<EntityStore, TransformComponent> transformComponentType) {
      this.pickupItemComponentType = pickupItemComponentType;
      this.transformComponentType = transformComponentType;
      this.query = Query.<EntityStore>and(pickupItemComponentType, transformComponentType);
   }

   public void tick(float dt, int index, @Nonnull ArchetypeChunk<EntityStore> archetypeChunk, @Nonnull Store<EntityStore> store, @Nonnull CommandBuffer<EntityStore> commandBuffer) {
      PickupItemComponent pickupItemComponent = (PickupItemComponent)archetypeChunk.getComponent(index, this.pickupItemComponentType);

      assert pickupItemComponent != null;

      if (pickupItemComponent.hasFinished()) {
         commandBuffer.removeEntity(archetypeChunk.getReferenceTo(index), RemoveReason.REMOVE);
      } else {
         Ref<EntityStore> targetRef = pickupItemComponent.getTargetRef();
         if (targetRef != null && targetRef.isValid()) {
            TransformComponent transformComponent = (TransformComponent)archetypeChunk.getComponent(index, this.transformComponentType);

            assert transformComponent != null;

            Vector3d position = transformComponent.getPosition();
            TransformComponent targetTransformComponent = (TransformComponent)commandBuffer.getComponent(targetRef, this.transformComponentType);

            assert targetTransformComponent != null;

            Vector3d targetPosition = targetTransformComponent.getPosition().clone();
            ModelComponent targetModelComponent = (ModelComponent)commandBuffer.getComponent(targetRef, ModelComponent.getComponentType());
            if (targetModelComponent != null) {
               float targetModelEyeHeight = targetModelComponent.getModel().getEyeHeight(targetRef, commandBuffer);
               targetPosition.add(0.0, (double)(targetModelEyeHeight / 5.0F), 0.0);
            }

            if (updateMovement(pickupItemComponent, position, targetPosition, dt)) {
               pickupItemComponent.setFinished(true);
            }

         } else {
            commandBuffer.removeEntity(archetypeChunk.getReferenceTo(index), RemoveReason.REMOVE);
         }
      }
   }

   private static boolean updateMovement(@Nonnull PickupItemComponent pickupItemComponent, @Nonnull Vector3d current, @Nonnull Vector3d target, float dt) {
      float remainingTime = pickupItemComponent.getLifeTime();
      float originalLifeTime = pickupItemComponent.getOriginalLifeTime();
      float progress = 1.0F - remainingTime / originalLifeTime;
      if (progress >= 1.0F) {
         current.assign(target);
         return true;
      } else {
         current.assign(Vector3d.lerp(pickupItemComponent.getStartPosition(), target, (double)progress));
         pickupItemComponent.decreaseLifetime(dt);
         return false;
      }
   }

   @Nonnull
   public Query<EntityStore> getQuery() {
      return this.query;
   }
}