const HEIGHT = 10;

​

let GRID_SIZE;

​

let entities = [

  {

    type: "player",

    x: 0,

    y: 0,

    dir: { x: 0, y: 0 },

    velocity: 0,

    canMove: true,

  },

   {

    type: "player",

    x: 0,

    y: 1,

    dir: { x: 0, y: 0 },

    velocity: 0,

    canMove: true,

  },

  {

    type: "player",

    x: 1,

    y: 0,

    dir: { x: 0, y: 0 },

    velocity: 0,

    canMove: true,

  },

  {

    type: "player",

    x: 2,

    y: 0,

    dir: { x: 0, y: 0 },

    velocity: 0,

    canMove: true,

  },

  {

    type: "player",

    x: 2,

    y: 1,

    dir: { x: 0, y: 0 },

    velocity: 0,

    canMove: true,

  },

  // { type: "box", x: 1, y: 0, dir: { x: 0, y: 0 }, velocity: 0, canMove: true },

  // { type: "box", x: 2, y: 0, dir: { x: 0, y: 0 }, velocity: 0, canMove: true },

  { type: "box", x: 3, y: 0, dir: { x: 0, y: 0 }, velocity: 0, canMove: true },

  // { type: "box", x: 1, y: 1, dir: { x: 0, y: 0 }, velocity: 0, canMove: true },

  { type: "box", x: 1, y: 2, dir: { x: 0, y: 0 }, velocity: 0, canMove: true },

  { type: "box", x: 1, y: 3, dir: { x: 0, y: 0 }, velocity: 0, canMove: true },

  { type: "wall", x: 3, y: 3, dir: { x: 0, y: 0 }, velocity: 0, canMove: false },

];

​

function setup() {

  createCanvas(400, 400);

​

  GRID_SIZE = floor(min(width / WIDTH, height / HEIGHT));

}

​

function draw() {

  background(220);

  // if (keyIsPressed && keyIsDown(SHIFT)) input(key);

  for (let i = 0; i < entities.length; i++) {

    const entity = entities[i];

    const { x, y } = entity;

    const pos = getDrawPos(x, y);

​

    switch (entity.type) {

      case "player":

        fill("white");

        rect(pos.x, pos.y, GRID_SIZE, GRID_SIZE);

        break;

      case "box":

        fill("orange");

        rect(pos.x, pos.y, GRID_SIZE, GRID_SIZE);

        break;

      case "wall":

        fill("black");

        rect(pos.x, pos.y, GRID_SIZE, GRID_SIZE);

        break;

    }

    textSize(GRID_SIZE);

    fill('black');

    text(i, pos.x + GRID_SIZE / 2 - textWidth(i) / 2, pos.y + GRID_SIZE / 2 + textSize() / 2.5);

  }

}

​

function getDrawPos(x, y) {

  return {

    x: x * GRID_SIZE,

    y: y * GRID_SIZE,

  };

}

​

function keyPressed(evt) {

  // console.log(evt);

  input(evt.key);

}

​

function input(key) {

  // console.log(key);

​

  switch (key) {

    case "ArrowRight":

      step({ type: "playerMove", delta: { x: 1, y: 0 } });

      break;

    case "ArrowLeft":

      step({ type: "playerMove", delta: { x: -1, y: 0 } });

      break;

    case "ArrowUp":

      step({ type: "playerMove", delta: { x: 0, y: -1 } });

      break;

    case "ArrowDown":

      step({ type: "playerMove", delta: { x: 0, y: 1 } });

      break;

  }

}

​

function step(action) {

  const new_entities = structuredClone(entities);

  // console.log(new_entities);

  switch (action.type) {

    case "playerMove":

      const { delta } = action;

      const players = new_entities.filter((entity) => entity.type === "player");

      players.forEach((player) => {

        player.dir = delta;

        player.velocity = keyIsDown(SHIFT) ? 3 : 1;

      });

      break;

  }

​

  let i = 0;

  for (; i < 1000; i++) {

    //printEntities(new_entities);

    if (!resolveEntities(new_entities)) return;

    if (isResolved(new_entities)) {

      // console.log("resolved!");

      break;

    }

  }

  // console.log("resolved", isResolved(new_entities), "steps", i, new_entities);

  entities = new_entities;

}

​

function resolveEntities(entities) {

  for (const entity of entities) {

    const { dir, velocity } = entity;

    if (velocity > 0) {

      entity.x += entity.dir.x;

      entity.y += entity.dir.y;

      entity.velocity--;

​

      entity.x = mod(entity.x, WIDTH);

      entity.y = mod(entity.y, HEIGHT);

​

      for (const entity2 of entities) {

        if (entity === entity2) continue;

        if (entity.x === entity2.x && entity.y === entity2.y) {

          if (!entity2.canMove) return false;

​

          entity2.velocity = 1;

          entity2.dir.x = entity.dir.x;

          entity2.dir.y = entity.dir.y;

        }

      }

    }

  }

​

  return true;

}

​

function isResolved(entities) {

  return entities.every((entity) => entity.velocity === 0);

}

​

function printEntities(entities) {

  for (const entity of entities) {

    console.log(JSON.stringify(entity));

  }

  console.log();

}

​

function mod(v, n) {

  return ((v % n) + n) % n;

}

​