OpenFrontIO/src/client/controllers/HoverHighlightController.ts

/**
 * HoverHighlightController — pushes the cursor's tile-owner to the WebGL
 * view so the territory + border passes can highlight the hovered player.
 *
 * Replaces the hover path inside the renderer's MapInteraction class (which
 * was bound to the WebGL canvas; that canvas has pointer-events: none in the
 * current input architecture so its listeners never fired). All input flows
 * through InputHandler → MouseMoveEvent on the EventBus, so we just listen.
 */

import { EventBus } from "../../core/EventBus";
import { GameView } from "../../core/game/GameView";
import { Controller } from "../Controller";
import { MouseMoveEvent } from "../InputHandler";
import { GameView as WebGLGameView } from "../render/gl";
import { OWNER_MASK } from "../render/gl/utils/TileCodec";
import { TransformHandler } from "../TransformHandler";

export class HoverHighlightController implements Controller {
  private lastOwnerID = 0;

  constructor(
    private game: GameView,
    private eventBus: EventBus,
    private transformHandler: TransformHandler,
    private view: WebGLGameView,
  ) {}

  init() {
    this.eventBus.on(MouseMoveEvent, (e) => this.onMouseMove(e));
  }

  private onMouseMove(e: MouseMoveEvent): void {
    const world = this.transformHandler.screenToWorldCoordinatesFloat(e.x, e.y);
    this.view.setMouseWorldPos(world.x, world.y);

    const cell = this.transformHandler.screenToWorldCoordinates(e.x, e.y);
    let ownerID = 0;
    if (this.game.isValidCoord(cell.x, cell.y)) {
      const ref = this.game.ref(cell.x, cell.y);
      ownerID = this.game.tileState(ref) & OWNER_MASK;
    }
    if (ownerID === this.lastOwnerID) return;
    this.lastOwnerID = ownerID;
    this.view.setHighlightOwner(ownerID);
  }
}