text: /*
   * Copyright (C) 2012-2016 Open Source Robotics Foundation
   *
   * 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 <gtest/gtest.h>
  
  #include "gazebo/math/Helpers.hh"
  #include "gazebo/math/Rand.hh"
  
  using namespace gazebo;
  
  class RandTest : public ::testing::Test { };
  
  //////////////////////////////////////////////////
  TEST_F(RandTest, Rand)
  {
    double d;
    int i;
    // TODO: implement a proper random number generator test
  
    d = gazebo::math::Rand::GetDblUniform(1, 2);
    EXPECT_LE(d, 2);
    EXPECT_GE(d, 1);
  
    i = math::Rand::GetIntUniform(1, 2);
    EXPECT_LE(i, 2);
    EXPECT_GE(i, 1);
  
    i = math::Rand::GetIntNormal(2, 3);
    EXPECT_LE(i, GZ_INT32_MAX);
    EXPECT_GE(i, -GZ_INT32_MAX);
  
    // Test setting the random number seed
    {
      // Set the seed and get two numbers
      math::Rand::SetSeed(1001);
      d = math::Rand::GetDblNormal(2, 3);
      i = math::Rand::GetIntNormal(2, 3);
  
      // Get two more numbers
      double d1 = math::Rand::GetDblNormal(2, 3);
      int i1 = math::Rand::GetIntNormal(2, 3);
  
      // and make sure they're different
      EXPECT_GT(std::abs(d - d1), 0);
      EXPECT_NE(i, i1);
  
      // Reset the seed to the original value
      math::Rand::SetSeed(1001);
  
      // Get two numbers again
      double d2 = math::Rand::GetDblNormal(2, 3);
      int i2 = math::Rand::GetIntNormal(2, 3);
  
      // and make sure they match the first numbers
      EXPECT_DOUBLE_EQ(d, d2);
      EXPECT_EQ(i, i2);
    }
  }
  
  //////////////////////////////////////////////////
  TEST_F(RandTest, SetSeed)
  {
    int N = 10;
    std::vector<int> first;
    std::vector<int> second;
  
    for (int i = 0; i < N; ++i)
    {
      math::Rand::SetSeed(i);
      first.push_back(math::Rand::GetIntUniform(-10, 10));
      second.push_back(math::Rand::GetIntUniform(-10, 10));
    }
  
    for (int i = 0; i < N; ++i)
    {
      math::Rand::SetSeed(i);
      EXPECT_EQ(first[i], math::Rand::GetIntUniform(-10, 10));
      EXPECT_EQ(second[i], math::Rand::GetIntUniform(-10, 10));
    }
  }
  