Ejemplo n.º 1
0
 /**
  * Ray-cast the world for all fixtures in the path of the ray. Your callback controls whether you
  * get the closest point, any point, or n-points. The ray-cast ignores shapes that contain the
  * starting point.
  *
  * @param callback a user implemented callback class.
  * @param point1 the ray starting point
  * @param point2 the ray ending point
  */
 public void raycast(RayCastCallback callback, Vec2 point1, Vec2 point2) {
   wrcwrapper.broadPhase = m_contactManager.m_broadPhase;
   wrcwrapper.callback = callback;
   input.maxFraction = 1.0f;
   input.p1.set(point1);
   input.p2.set(point2);
   m_contactManager.m_broadPhase.raycast(wrcwrapper, input);
 }
Ejemplo n.º 2
0
  @Override
  public void raycast(
      org.jbox2d.callbacks.TreeRayCastCallback callback, org.jbox2d.collision.RayCastInput input) {
    final Vec2 p1 = input.p1;
    final Vec2 p2 = input.p2;
    float p1x = p1.x, p2x = p2.x, p1y = p1.y, p2y = p2.y;
    float vx, vy;
    float rx, ry;
    float absVx, absVy;
    float cx, cy;
    float hx, hy;
    float tempx, tempy;
    r.x = p2x - p1x;
    r.y = p2y - p1y;
    assert ((r.x * r.x + r.y * r.y) > 0f);
    r.normalize();
    rx = r.x;
    ry = r.y;

    // v is perpendicular to the segment.
    vx = -1f * ry;
    vy = 1f * rx;
    absVx = org.jbox2d.common.MathUtils.abs(vx);
    absVy = org.jbox2d.common.MathUtils.abs(vy);

    // Separating axis for segment (Gino, p80).
    // |dot(v, p1 - c)| > dot(|v|, h)

    float maxFraction = input.maxFraction;

    // Build a bounding box for the segment.
    final org.jbox2d.collision.AABB segAABB = aabb;
    // Vec2 t = p1 + maxFraction * (p2 - p1);
    // before inline
    // temp.set(p2).subLocal(p1).mulLocal(maxFraction).addLocal(p1);
    // Vec2.minToOut(p1, temp, segAABB.lowerBound);
    // Vec2.maxToOut(p1, temp, segAABB.upperBound);
    tempx = (p2x - p1x) * maxFraction + p1x;
    tempy = (p2y - p1y) * maxFraction + p1y;
    segAABB.lowerBound.x = p1x < tempx ? p1x : tempx;
    segAABB.lowerBound.y = p1y < tempy ? p1y : tempy;
    segAABB.upperBound.x = p1x > tempx ? p1x : tempx;
    segAABB.upperBound.y = p1y > tempy ? p1y : tempy;
    // end inline

    nodeStackIndex = 0;
    nodeStack[nodeStackIndex++] = m_root;
    while (nodeStackIndex > 0) {
      final DynamicTreeNode node = nodeStack[--nodeStackIndex];
      if (node == null) {
        continue;
      }

      final org.jbox2d.collision.AABB nodeAABB = node.aabb;
      if (!org.jbox2d.collision.AABB.testOverlap(nodeAABB, segAABB)) {
        continue;
      }

      // Separating axis for segment (Gino, p80).
      // |dot(v, p1 - c)| > dot(|v|, h)
      // node.aabb.getCenterToOut(c);
      // node.aabb.getExtentsToOut(h);
      cx = (nodeAABB.lowerBound.x + nodeAABB.upperBound.x) * .5f;
      cy = (nodeAABB.lowerBound.y + nodeAABB.upperBound.y) * .5f;
      hx = (nodeAABB.upperBound.x - nodeAABB.lowerBound.x) * .5f;
      hy = (nodeAABB.upperBound.y - nodeAABB.lowerBound.y) * .5f;
      tempx = p1x - cx;
      tempy = p1y - cy;
      float separation =
          org.jbox2d.common.MathUtils.abs(vx * tempx + vy * tempy) - (absVx * hx + absVy * hy);
      if (separation > 0.0f) {
        continue;
      }

      if (node.child1 == null) {
        subInput.p1.x = p1x;
        subInput.p1.y = p1y;
        subInput.p2.x = p2x;
        subInput.p2.y = p2y;
        subInput.maxFraction = maxFraction;

        float value = callback.raycastCallback(subInput, node.id);

        if (value == 0.0f) {
          // The client has terminated the ray cast.
          return;
        }

        if (value > 0.0f) {
          // Update segment bounding box.
          maxFraction = value;
          // temp.set(p2).subLocal(p1).mulLocal(maxFraction).addLocal(p1);
          // Vec2.minToOut(p1, temp, segAABB.lowerBound);
          // Vec2.maxToOut(p1, temp, segAABB.upperBound);
          tempx = (p2x - p1x) * maxFraction + p1x;
          tempy = (p2y - p1y) * maxFraction + p1y;
          segAABB.lowerBound.x = p1x < tempx ? p1x : tempx;
          segAABB.lowerBound.y = p1y < tempy ? p1y : tempy;
          segAABB.upperBound.x = p1x > tempx ? p1x : tempx;
          segAABB.upperBound.y = p1y > tempy ? p1y : tempy;
        }
      } else {
        if (nodeStack.length - nodeStackIndex - 2 <= 0) {
          DynamicTreeNode[] newBuffer = new DynamicTreeNode[nodeStack.length * 2];
          System.arraycopy(nodeStack, 0, newBuffer, 0, nodeStack.length);
          nodeStack = newBuffer;
        }
        nodeStack[nodeStackIndex++] = node.child1;
        nodeStack[nodeStackIndex++] = node.child2;
      }
    }
  }