krouzek:matterjs [Kroužek Javascriptu]

Tato stránka je pouze pro čtení. Můžete si pouze prohlédnout zdrojový kód, ale ne ho měnit. Zeptejte se správce, pokud si myslíte, že něco není v pořádku.
  * [[https://brm.io/matter-js/docs/|Dokumentace matter js]]
  * Kód k experimentování, aneb co vygenerovala ChatGPT (na třetí pokus, prompt "Can you create a simple angry birds clone using matter.js?")

<code html>
<!DOCTYPE html>
<html>
<head>
  <title>Angry Birds Clone</title>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/matter-js/0.17.1/matter.min.js"></script>
  <style>
    body { margin: 0; }
    canvas { display: block; }
  </style>
</head>
<body>
  <script>
    // Module aliases
    const { Engine, Render, Runner, Bodies, Mouse, MouseConstraint, World, Constraint, Vector } = Matter;

    // Create an engine
    const engine = Engine.create();
    const world = engine.world;

    // Create a renderer
    const render = Render.create({
      element: document.body,
      engine: engine,
      options: {
        width: 800,
        height: 600,
        wireframes: false,
        background: '#87CEEB'
      }
    });

    // Create ground
    const ground = Bodies.rectangle(400, 590, 810, 60, { isStatic: true });
    World.add(world, ground);

    // Create bird
    const bird = Bodies.circle(150, 300, 20, { density: 0.004 });
    World.add(world, bird);

    // Create slingshot
    let slingshot = Constraint.create({
      pointA: { x: 150, y: 300 },
      bodyB: bird,
      stiffness: 0.05,
      length: 0
    });
    World.add(world, slingshot);

    // Create targets (blocks)
    const createBlock = (x, y) => {
      return Bodies.rectangle(x, y, 40, 40, {
        restitution: 0.8,
        friction: 0.5
      });
    };

    const blocks = [
      createBlock(600, 550),
      createBlock(650, 550),
      createBlock(700, 550),
      createBlock(625, 500),
      createBlock(675, 500),
      createBlock(650, 450)
    ];
    World.add(world, blocks);

    // Add mouse control
    const mouse = Mouse.create(render.canvas);
    const mouseConstraint = MouseConstraint.create(engine, {
      mouse: mouse,
      constraint: {
        stiffness: 0.2,
        render: { visible: false }
      }
    });
    World.add(world, mouseConstraint);

    // Variables to track bird's position and slingshot release
    let isBirdReleased = false;
    let birdStartPosition = { x: 150, y: 300 };

    // Event to handle end drag
    Matter.Events.on(mouseConstraint, 'enddrag', (event) => {
      if (event.body === bird) {
        slingshot.bodyB = null;
        isBirdReleased = true;
      }
    });

    // Reset bird position
    const resetBird = () => {
      Matter.Body.setPosition(bird, birdStartPosition);
      Matter.Body.setVelocity(bird, { x: 0, y: 0 });
      Matter.Body.setAngularVelocity(bird, 0);
      slingshot.bodyB = bird;
      isBirdReleased = false;
    };

    // Apply force to the bird when it is released
    Matter.Events.on(engine, 'afterUpdate', () => {
      if (isBirdReleased) {
        const forceMagnitude = 0.02 * bird.mass;
        const slingshotVector = Vector.sub(slingshot.pointA, bird.position);
        const normalizedVector = Vector.normalise(slingshotVector);
        const force = Vector.mult(normalizedVector, forceMagnitude);
        Matter.Body.applyForce(bird, bird.position, force);
        isBirdReleased = false; // Ensure force is applied only once
      }

      // Check if bird is out of bounds
      if (bird.position.x > 800 || bird.position.y > 600 || bird.position.x < 0 || bird.position.y < 0) {
        resetBird();
      }
    });

    // Run the engine and renderer
    Engine.run(engine);
    Render.run(render);
  </script>
</body>
</html>

</code>