// * This file is part of the COLOBOT source code
// * Copyright (C) 2012, Polish Portal of Colobot (PPC)
// *
// * This program is free software: you can redistribute it and/or modify
// * it under the terms of the GNU General Public License as published by
// * the Free Software Foundation, either version 3 of the License, or
// * (at your option) any later version.
// *
// * This program is distributed in the hope that it will be useful,
// * but WITHOUT ANY WARRANTY; without even the implied warranty of
// * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// * GNU General Public License for more details.
// *
// * You should have received a copy of the GNU General Public License
// * along with this program. If not, see  http://www.gnu.org/licenses/.

/*
  Unit tests for Vector struct

  Test data was randomly generated and the expected results
  calculated using GNU Octave.
 */

#include "math/func.h"
#include "math/vector.h"

#include "gtest/gtest.h"


const float TEST_TOLERANCE = 1e-6;


TEST(VectorTest, LengthTest)
{
    Math::Vector vec(-1.288447945923275, 0.681452565308134, -0.633761098985957);
    const float expectedLength = 1.58938001708428;

    EXPECT_TRUE(Math::IsEqual(vec.Length(), expectedLength, TEST_TOLERANCE));
}

TEST(VectorTest, NormalizeTest)
{
    Math::Vector vec(1.848877241804398, -0.157262961268577, -1.963031403332377);
    const Math::Vector expectedNormalized(0.6844609421393856, -0.0582193085618106, -0.7267212194481797);

    vec.Normalize();

    EXPECT_TRUE(Math::VectorsEqual(vec, expectedNormalized, TEST_TOLERANCE));
}

TEST(VectorTest, DotTest)
{
    Math::Vector vecA(0.8202190530968309, 0.0130926060162780, 0.2411914183883510);
    Math::Vector vecB(-0.0524083951404069, 1.5564932716738220, -0.8971342631500536);

    float expectedDot = -0.238988896477326;

    EXPECT_TRUE(Math::IsEqual(Math::DotProduct(vecA, vecB), expectedDot, TEST_TOLERANCE));
}

TEST(VectorTest, CrossTest)
{
    Math::Vector vecA(1.37380499798567, 1.18054518384682, 1.95166361293121);
    Math::Vector vecB(0.891657855926886, 0.447591335394532, -0.901604070087823);

    Math::Vector expectedCross(-1.937932065431669, 2.978844370287636, -0.437739173833581);
    Math::Vector expectedReverseCross = -expectedCross;

    EXPECT_TRUE(Math::VectorsEqual(vecA.CrossMultiply(vecB), expectedCross, TEST_TOLERANCE));

    EXPECT_TRUE(Math::VectorsEqual(vecB.CrossMultiply(vecA), expectedReverseCross, TEST_TOLERANCE));
}