silphius/app/react-components/ecs.jsx

import {Container} from '@pixi/react';
import {useState} from 'react';

import {RESOLUTION} from '@/constants.js';
import {useEcs, useEcsTick} from '@/context/ecs.js';
import {useMainEntity} from '@/context/main-entity.js';

import Entities from './entities.jsx';
import TargetingGhost from './targeting-ghost.jsx';
import TargetingGrid from './targeting-grid.jsx';
import TileLayer from './tile-layer.jsx';

export default function EcsComponent() {
  const [ecs] = useEcs();
  const [entities, setEntities] = useState({});
  const [mainEntity] = useMainEntity();
  useEcsTick((payload) => {
    const updatedEntities = {...entities};
    for (const id in payload) {
      const update = payload[id];
      if (false === update) {
        delete updatedEntities[id];
      }
      else {
        updatedEntities[id] = ecs.get(id);
        if (update.Emitter?.emit) {
          updatedEntities[id].Emitter.emitting = {
            ...updatedEntities[id].Emitter.emitting,
            ...update.Emitter.emit,
          };
        }
      }
    }
    setEntities(updatedEntities);
  }, [ecs, entities, mainEntity]);
  if (!mainEntity) {
    return false;
  }
  const entity = ecs.get(mainEntity);
  const {Direction, Position, Wielder} = entity;
  const projected = Wielder.activeItem()?.project(Position.tile, Direction.direction)
  const {Camera} = entity;
  const {TileLayers: {layers: [layer]}} = ecs.get(1);
  const [cx, cy] = [
    Math.round(Camera.x - RESOLUTION.x / 2),
    Math.round(Camera.y - RESOLUTION.y / 2),
  ];
  return (
    <Container
      x={-cx}
      y={-cy}
    >
      <TileLayer tileLayer={layer} />
      {projected && (
        <TargetingGrid
          tileLayer={layer}
          x={Position.x}
          y={Position.y}
        />
      )}
      <Entities entities={entities} />
      {projected?.length > 0 && (
        <TargetingGhost
          projected={projected}
          tileLayer={layer}
        />
      )}
    </Container>
  )
}