text: /*
   * Copyright (C) 2013 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
   * in compliance with the License. You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software distributed under the License
   * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
   * or implied. See the License for the specific language governing permissions and limitations under
   * the License.
   */
  #include "Vector2D.h"
  
  #include <math.h>
  
  Vector2D::Vector2D() :
          mX(0), mY(0) {
  }
  
  Vector2D::Vector2D(float x, float y) :
          mX(x), mY(y) {
  }
  
  Vector2D Vector2D::copy() {
      Vector2D v(mX, mY);
      return v;
  }
  
  void Vector2D::add(const Vector2D& v) {
      mX += v.mX;
      mY += v.mY;
  }
  
  void Vector2D::sub(const Vector2D& v) {
      mX -= v.mX;
      mY -= v.mY;
  }
  
  void Vector2D::scale(float s) {
      mX *= s;
      mY *= s;
  }
  
  float Vector2D::distance(const Vector2D& v) {
      float dx = mX - v.mX;
      float dy = mY - v.mY;
      return (float) sqrt(dx * dx + dy * dy);
  }
  
  void Vector2D::normalize() {
      float m = magnitude();
      if (m > 0) {
          scale(1 / m);
      }
  }
  
  void Vector2D::limit(float max) {
      if (magnitude() > max) {
          normalize();
          scale(max);
      }
  }
  
  float Vector2D::magnitude() {
      return (float) sqrt(mX * mX + mY * mY);
  }
  