Ejemplo n.º 1
0
  /** 创建多边形物体 */
  private void createBody() {
    // 定义物体的形状是多边形形状
    PolygonShape shape = new PolygonShape();
    shape.set(vecs, edge);

    // 设置多边形物体的一些固定的物理属性
    FixtureDef fd = new FixtureDef();
    fd.shape = shape;
    // 固定设置参数
    fd.density = 5.0f; // 密度
    fd.friction = 0.3f; // 摩擦系数
    fd.restitution = restitution; // 恢复系数

    BodyDef bd = new BodyDef();
    bd.position.set(x, y);
    bd.type = BodyType.DYNAMIC;
    bd.angle = angle;
    bd.allowSleep = true;
    bd.setAwake(true);

    // 根据bodyDef创建物体到世界中
    body = world.createBody(bd);
    // 设置好物体的固定属性
    body.createFixture(fd);
  }
  @Test
  public void testIsWoundCorrectly() {
    PolygonShape shape = new PolygonShape();

    Vec2 lineVertices[] = new Vec2[] {new Vec2(-1.0f, -1.0f), new Vec2(1.0f, 1.0f)};
    shape.set(lineVertices, lineVertices.length);
    assertFalse(GeometryVerifier.IsWoundCorrectly(shape));

    Vec2 boxVertices[] =
        new Vec2[] {
          new Vec2(0.25f, 0.25f),
          new Vec2(-0.25f, 0.25f),
          new Vec2(-0.25f, -0.25f),
          new Vec2(0.25f, -0.25f)
        };
    shape.set(boxVertices, boxVertices.length);
    assertTrue(GeometryVerifier.IsWoundCorrectly(shape));

    Vec2 miswoundBoxVertices[] =
        new Vec2[] {
          new Vec2(0.25f, -0.25f),
          new Vec2(-0.25f, -0.25f),
          new Vec2(-0.25f, 0.25f),
          new Vec2(0.25f, 0.25f)
        };
    shape.set(miswoundBoxVertices, miswoundBoxVertices.length);
    assertFalse(GeometryVerifier.IsWoundCorrectly(shape));

    Vec2 potatoVertices[] =
        new Vec2[] {
          new Vec2(4.0f, 4.0f),
          new Vec2(5.0f, 3.0f),
          new Vec2(4.0f, 1.0f),
          new Vec2(2.0f, 2.0f),
          new Vec2(3.0f, 3.0f),
          new Vec2(2.0f, 5.0f)
        };
    shape.set(potatoVertices, potatoVertices.length);
    assertFalse(GeometryVerifier.IsWoundCorrectly(shape));
  }
 /**
  * Create a convex hull from the given array of points. The count must be in the range [3,
  * Settings.maxPolygonVertices].
  *
  * @warning the points may be re-ordered, even if they form a convex polygon
  * @warning collinear points are handled but not removed. Collinear points may lead to poor
  *     stacking behavior.
  */
 public final void set(final Vec2[] vertices, final int count) {
   set(vertices, count, null, null);
 }
Ejemplo n.º 4
0
  /**
   * Rozbije objekt. Upravi objekt world tak, ze vymaze triesteny objekt a nahradi ho fragmentami na
   * zaklade nastaveneho materialu a clenskych premennych.
   *
   * @param dt casova dlzka framu
   */
  public void smash(float dt) {
    if (contact == null) { // riesi sa staticky prvok, ktory ma priliz maly obsah
      b1.setType(BodyType.DYNAMIC);
      return;
    }

    World w = b1.m_world;
    Shape s = f1.m_shape;
    Polygon p = f1.m_polygon;

    if (p == null) {
      switch (s.m_type) {
        case POLYGON:
          PolygonShape ps = (PolygonShape) s;
          Vec2[] vertices = ps.m_vertices;
          p = new Polygon();
          for (int i = 0; i < ps.m_count; ++i) {
            p.add(vertices[ps.m_count - i - 1]);
          }
          break;
        case CIRCLE:
          CircleShape cs = (CircleShape) s;
          p = new Polygon();
          float radius = cs.m_radius;

          double u = Math.PI * 2 / CIRCLEVERTICES;
          radius =
              (float) Math.sqrt(u / Math.sin(u))
                  * radius; // upravim radius tak, aby bola zachovana velkost obsahu

          Vec2 center = cs.m_p;
          for (int i = 0; i < CIRCLEVERTICES; ++i) {
            double j = u * i; // uhol
            float sin = (float) Math.sin(j);
            float cos = (float) Math.cos(j);
            Vec2 v = new Vec2(sin, cos).mulLocal(radius).addLocal(center);
            p.add(v);
          }
          break;
        default:
          throw new RuntimeException("Dany typ tvaru nepodporuje stiepenie");
      }
    }

    float mConst = f1.m_material.m_rigidity / normalImpulse; // sila v zavislosti na pevnosti telesa

    boolean fixA = f1 == contact.m_fixtureA; // true, ak f2 je v objekte contact ako m_fixtureA
    float oldAngularVelocity =
        fixA ? contact.m_angularVelocity_bodyA : contact.m_angularVelocity_bodyB;
    Vec2 oldLinearVelocity = fixA ? contact.m_linearVelocity_bodyA : contact.m_linearVelocity_bodyB;
    b1.setAngularVelocity(
        (b1.m_angularVelocity - oldAngularVelocity) * mConst + oldAngularVelocity);
    b1.setLinearVelocity(
        b1.m_linearVelocity.sub(oldLinearVelocity).mulLocal(mConst).addLocal(oldLinearVelocity));
    if (!w.isFractured(f2)
        && b2.m_type == BodyType.DYNAMIC
        && !b2.m_fractureTransformUpdate) { // ak sa druhy objekt nerozbija, tak sa jej nahodia
      // povodne hodnoty (TREBA MODIFIKOVAT POHYB OBJEKTU,
      // KTORY SPOSOBUJE ROZPAD)
      oldAngularVelocity =
          !fixA ? contact.m_angularVelocity_bodyA : contact.m_angularVelocity_bodyB;
      oldLinearVelocity = !fixA ? contact.m_linearVelocity_bodyA : contact.m_linearVelocity_bodyB;
      b2.setAngularVelocity(
          (b2.m_angularVelocity - oldAngularVelocity) * mConst + oldAngularVelocity);
      b2.setLinearVelocity(
          b2.m_linearVelocity.sub(oldLinearVelocity).mulLocal(mConst).addLocal(oldLinearVelocity));
      b2.setTransform(
          b2.m_xf0.p.add(b2.m_linearVelocity.mul(dt)),
          b2.m_xf0.q.getAngle()); // osetruje jbox2d od posuvania telesa pri rieseni kolizie
      b2.m_fractureTransformUpdate = true;
    }

    Vec2 localPoint = Transform.mulTrans(b1.m_xf, point);
    Vec2 b1Vec = b1.getLinearVelocityFromWorldPoint(point);
    Vec2 b2Vec = b2.getLinearVelocityFromWorldPoint(point);
    Vec2 localVector = b2Vec.subLocal(b1Vec);

    localVector.mulLocal(dt);
    Polygon[] fragment;
    try {
      fragment = m.split(p, localPoint, localVector, normalImpulse); // rodeli to
    } catch (RuntimeException ex) {
      return;
    }

    if (fragment.length == 1) { // nerozbilo to na ziadne fragmenty
      return;
    }

    // definuje tela fragmentov - tie maju vsetky rovnaku definiciu (preberaju parametre z povodneho
    // objektu)
    BodyDef bodyDef = new BodyDef();
    bodyDef.position.set(b1.m_xf.p); // pozicia
    bodyDef.angle = b1.m_xf.q.getAngle(); // otocenie
    bodyDef.fixedRotation = b1.isFixedRotation();
    bodyDef.angularDamping = b1.m_angularDamping;
    bodyDef.allowSleep = b1.isSleepingAllowed();

    FixtureDef fd = new FixtureDef();
    fd.friction = f1.m_friction; // trenie
    fd.restitution = f1.m_restitution; // odrazivost
    fd.isSensor = f1.m_isSensor;
    fd.density = f1.m_density;

    // odstrani fragmentacne predmety/cele teleso
    ArrayList<Fixture> fixtures = new ArrayList<>();
    if (f1.m_polygon != null) {
      for (Fixture f = b1.m_fixtureList; f != null; f = f.m_next) {
        if (f.m_polygon == f1.m_polygon) {
          fixtures.add(f);
        }
      }
    } else {
      fixtures.add(f1);
    }

    for (Fixture f : fixtures) {
      b1.destroyFixture(f);
    }

    if (b1.m_fixtureCount == 0) {
      w.destroyBody(b1);
    }

    // prida fragmenty do simulacie
    MyList<Body> newbodies = new MyList<>();
    for (Polygon pg : fragment) { // vytvori tela, prida fixtury, poriesi konvexnu dekompoziciu
      if (pg.isCorrect()) {
        if (pg instanceof Fragment) {
          Polygon[] convex = pg.convexDecomposition();
          bodyDef.type = BodyType.DYNAMIC;
          for (Polygon pgx : convex) {
            Body f_body = w.createBody(bodyDef);
            pgx.flip();
            PolygonShape ps = new PolygonShape();
            ps.set(pgx.getArray(), pgx.size());
            fd.shape = ps;
            fd.polygon = null;
            fd.material = f1.m_material.m_fragments; // rekurzivne stiepenie

            f_body.createFixture(fd);
            f_body.setAngularVelocity(b1.m_angularVelocity);
            f_body.setLinearVelocity(b1.getLinearVelocityFromLocalPoint(f_body.getLocalCenter()));
            newbodies.add(f_body);
          }

        } else {
          fd.material = f1.m_material.m_fragments; // rekurzivne stiepenie
          bodyDef.type = b1.getType();
          Body f_body = w.createBody(bodyDef);
          PolygonFixture pf = new PolygonFixture(pg);

          f_body.createFixture(pf, fd);
          f_body.setLinearVelocity(b1.getLinearVelocityFromLocalPoint(f_body.getLocalCenter()));
          f_body.setAngularVelocity(b1.m_angularVelocity);
          newbodies.add(f_body);
        }
      }
    }

    // zavola sa funkcia z fraction listeneru (pokial je nadefinovany)
    FractureListener fl = w.getContactManager().m_fractureListener;
    if (fl != null) {
      fl.action(m, normalImpulse, newbodies);
    }
  }