ecs-observable/examples/tetris/components.ts

import { defineComponent } from "../../src/component";
import type { World } from "../../src/index";
import {
  randomPiece,
  collides,
  lockPiece,
  clearLines,
  scoreForLines,
  BOARD_W,
} from "./game";

// ── Component definitions ────────────────────────────

/** The playfield grid (20 rows × 10 cols). 0 = empty, non-zero = color index. */
export const Board = defineComponent("board", {
  grid: Array.from({ length: 20 }, () => new Uint8Array(10)) as Uint8Array[],
});

// ── Active piece ─────────────────────────────────────
export const Piece = defineComponent("piece", {
  shape: [] as number[][],
  color: 1,
  x: 3,
  y: 0,
});

// ── Score / state ────────────────────────────────────
export const Score = defineComponent("score", {
  points: 0,
  lines: 0,
  level: 1,
});

export const GameOver = defineComponent("gameOver", {});
export const Paused = defineComponent("paused", {});

// ── Timing ───────────────────────────────────────────
export const TickTimer = defineComponent("tickTimer", {
  accumulator: 0,
  interval: 800, // ms between gravity ticks
});

// ── Piece helpers ────────────────────────────────────

export function createPieceHelpers(world: World) {
  return {
    spawnPiece(): void {
      const p = randomPiece();
      world.addSingleton(Piece, {
        shape: p.shape,
        color: p.color,
        x: Math.floor((BOARD_W - p.shape[0].length) / 2),
        y: 0,
      });
    },

    lockAndSpawn(): void {
      const piece = world.getSingleton(Piece);
      const board = world.getSingleton(Board);

      lockPiece(board.grid, piece.shape, piece.color, piece.x, piece.y);
      world.removeSingleton(Piece);

      const cleared = clearLines(board.grid);
      if (cleared > 0) {
        const score = world.getSingleton(Score);
        score.lines += cleared;
        score.points += scoreForLines(cleared, score.level);
        score.level = Math.floor(score.lines / 10) + 1;
        const timer = world.getSingleton(TickTimer);
        timer.interval = Math.max(100, 800 - (score.level - 1) * 70);
      }

      this.spawnPiece();

      const newPiece = world.getSingleton(Piece);
      if (collides(board.grid, newPiece.shape, newPiece.x, newPiece.y)) {
        world.removeSingleton(Piece);
        world.addSingleton(GameOver);
      }
    },
  };
}