Vec3/tests/unit_tests/vec_test.cpp

#include "vec3.h"
#include <cmath>
#include <gtest/gtest.h>
#include <limits>

// Test fixture for Vec3 tests
class Vec3Test : public ::testing::Test {
protected:
  // Test vectors that will be used across multiple tests
  Vec3<int> intVec1, intVec2;
  Vec3<float> floatVec1, floatVec2;
  Vec3<double> doubleVec1, doubleVec2;

  void SetUp() override {
    // Initialize test vectors
    intVec1 = {1, 2, 3};
    intVec2 = {4, 5, 6};

    floatVec1 = {1.5f, 2.5f, 3.5f};
    floatVec2 = {4.5f, 5.5f, 6.5f};

    doubleVec1 = {1.5, 2.5, 3.5};
    doubleVec2 = {4.5, 5.5, 6.5};
  }
};

// Test vector addition
TEST_F(Vec3Test, Addition) {
  // Test integer vectors
  auto intResult = intVec1 + intVec2;
  EXPECT_EQ(intResult.x, 5);
  EXPECT_EQ(intResult.y, 7);
  EXPECT_EQ(intResult.z, 9);

  // Test float vectors
  auto floatResult = floatVec1 + floatVec2;
  EXPECT_FLOAT_EQ(floatResult.x, 6.0f);
  EXPECT_FLOAT_EQ(floatResult.y, 8.0f);
  EXPECT_FLOAT_EQ(floatResult.z, 10.0f);

  // Test double vectors
  auto doubleResult = doubleVec1 + doubleVec2;
  EXPECT_DOUBLE_EQ(doubleResult.x, 6.0);
  EXPECT_DOUBLE_EQ(doubleResult.y, 8.0);
  EXPECT_DOUBLE_EQ(doubleResult.z, 10.0);
}

// Test vector subtraction
TEST_F(Vec3Test, Subtraction) {
  // Test integer vectors
  auto intResult = intVec2 - intVec1;
  EXPECT_EQ(intResult.x, 3);
  EXPECT_EQ(intResult.y, 3);
  EXPECT_EQ(intResult.z, 3);

  // Test float vectors
  auto floatResult = floatVec2 - floatVec1;
  EXPECT_FLOAT_EQ(floatResult.x, 3.0f);
  EXPECT_FLOAT_EQ(floatResult.y, 3.0f);
  EXPECT_FLOAT_EQ(floatResult.z, 3.0f);

  // Test double vectors
  auto doubleResult = doubleVec2 - doubleVec1;
  EXPECT_DOUBLE_EQ(doubleResult.x, 3.0);
  EXPECT_DOUBLE_EQ(doubleResult.y, 3.0);
  EXPECT_DOUBLE_EQ(doubleResult.z, 3.0);
}

// Test vector scaling
TEST_F(Vec3Test, Scale) {
  // Test integer scaling
  Vec3<int> intVecScaled = intVec1;
  intVecScaled.scale(2);
  EXPECT_EQ(intVecScaled.x, 2);
  EXPECT_EQ(intVecScaled.y, 4);
  EXPECT_EQ(intVecScaled.z, 6);

  // Test float scaling
  Vec3<float> floatVecScaled = floatVec1;
  floatVecScaled.scale(2.0f);
  EXPECT_FLOAT_EQ(floatVecScaled.x, 3.0f);
  EXPECT_FLOAT_EQ(floatVecScaled.y, 5.0f);
  EXPECT_FLOAT_EQ(floatVecScaled.z, 7.0f);

  // Test double scaling
  Vec3<double> doubleVecScaled = doubleVec1;
  doubleVecScaled.scale(2.0);
  EXPECT_DOUBLE_EQ(doubleVecScaled.x, 3.0);
  EXPECT_DOUBLE_EQ(doubleVecScaled.y, 5.0);
  EXPECT_DOUBLE_EQ(doubleVecScaled.z, 7.0);

  // Test scaling by zero
  Vec3<float> zeroScaled = floatVec1;
  zeroScaled.scale(0.0f);
  EXPECT_FLOAT_EQ(zeroScaled.x, 0.0f);
  EXPECT_FLOAT_EQ(zeroScaled.y, 0.0f);
  EXPECT_FLOAT_EQ(zeroScaled.z, 0.0f);

  // Test scaling by negative number
  Vec3<int> negScaled = intVec1;
  negScaled.scale(-1);
  EXPECT_EQ(negScaled.x, -1);
  EXPECT_EQ(negScaled.y, -2);
  EXPECT_EQ(negScaled.z, -3);
}

// Test dot product
TEST_F(Vec3Test, DotProduct) {
  // Test integer dot product
  int intDot = intVec1.dot(intVec2);
  EXPECT_EQ(intDot, 32); // 1*4 + 2*5 + 3*6 = 4 + 10 + 18 = 32

  // Test float dot product
  float floatDot = floatVec1.dot(floatVec2);
  EXPECT_FLOAT_EQ(
      floatDot,
      43.25f); // 1.5*4.5 + 2.5*5.5 + 3.5*6.5 = 6.75 + 13.75 + 22.75 = 43.25

  // Test double dot product
  double doubleDot = doubleVec1.dot(doubleVec2);
  EXPECT_DOUBLE_EQ(doubleDot, 43.25); // Same calculation as float

  // Test dot product with self (should equal squared length)
  int selfDot = intVec1.dot(intVec1);
  EXPECT_EQ(selfDot, 14); // 1*1 + 2*2 + 3*3 = 1 + 4 + 9 = 14

  // Test dot product with zero vector
  Vec3<int> zeroVec = {0, 0, 0};
  EXPECT_EQ(intVec1.dot(zeroVec), 0);
}

// Test cross product
TEST_F(Vec3Test, CrossProduct) {
  // Test integer cross product
  auto intCross = intVec1.cross(intVec2);
  EXPECT_EQ(intCross.x, -3); // (2*6 - 3*5) = 12 - 15 = -3
  EXPECT_EQ(intCross.y, 6);  // (3*4 - 1*6) = 12 - 6 = 6
  EXPECT_EQ(intCross.z, -3); // (1*5 - 2*4) = 5 - 8 = -3

  // Test float cross product
  auto floatCross = floatVec1.cross(floatVec2);
  EXPECT_FLOAT_EQ(floatCross.x,
                  -3.0f); // (2.5*6.5 - 3.5*5.5) = 16.25 - 19.25 = -3
  EXPECT_FLOAT_EQ(floatCross.y,
                  6.0f); // (3.5*4.5 - 1.5*6.5) = 15.75 - 9.75 = 6
  EXPECT_FLOAT_EQ(floatCross.z,
                  -3.0f); // (1.5*5.5 - 2.5*4.5) = 8.25 - 11.25 = -3

  // Test double cross product
  auto doubleCross = doubleVec1.cross(doubleVec2);
  EXPECT_DOUBLE_EQ(doubleCross.x, -3.0);
  EXPECT_DOUBLE_EQ(doubleCross.y, 6.0);
  EXPECT_DOUBLE_EQ(doubleCross.z, -3.0);

  // Test cross product with self (should be zero)
  auto selfCross = intVec1.cross(intVec1);
  EXPECT_EQ(selfCross.x, 0);
  EXPECT_EQ(selfCross.y, 0);
  EXPECT_EQ(selfCross.z, 0);

  // Test cross product of standard basis vectors (i × j = k)
  Vec3<int> i = {1, 0, 0};
  Vec3<int> j = {0, 1, 0};
  Vec3<int> k = {0, 0, 1};

  auto i_cross_j = i.cross(j);
  EXPECT_EQ(i_cross_j.x, 0);
  EXPECT_EQ(i_cross_j.y, 0);
  EXPECT_EQ(i_cross_j.z, 1);

  auto j_cross_k = j.cross(k);
  EXPECT_EQ(j_cross_k.x, 1);
  EXPECT_EQ(j_cross_k.y, 0);
  EXPECT_EQ(j_cross_k.z, 0);

  auto k_cross_i = k.cross(i);
  EXPECT_EQ(k_cross_i.x, 0);
  EXPECT_EQ(k_cross_i.y, 1);
  EXPECT_EQ(k_cross_i.z, 0);
}

// Test with edge cases
TEST_F(Vec3Test, EdgeCases) {
  // Test with max values
  Vec3<int> maxVec = {std::numeric_limits<int>::max(),
                      std::numeric_limits<int>::max(),
                      std::numeric_limits<int>::max()};

  // Addition with max values may overflow, but we want to test the operation
  // works
  auto maxAddition = maxVec + intVec1;

  // Test with min values
  Vec3<int> minVec = {std::numeric_limits<int>::min(),
                      std::numeric_limits<int>::min(),
                      std::numeric_limits<int>::min()};

  // Subtraction with min values may underflow, but we want to test the
  // operation works
  auto minSubtraction = minVec - intVec1;

  // Test with mixed values
  Vec3<double> mixedVec1 = {0.0, -1.0, std::numeric_limits<double>::infinity()};
  Vec3<double> mixedVec2 = {-0.0, 1.0,
                            -std::numeric_limits<double>::infinity()};

  auto mixedAddition = mixedVec1 + mixedVec2;
  // 0.0 + (-0.0) = 0.0
  EXPECT_DOUBLE_EQ(mixedAddition.x, 0.0);
  // -1.0 + 1.0 = 0.0
  EXPECT_DOUBLE_EQ(mixedAddition.y, 0.0);
  // inf + (-inf) = NaN
  EXPECT_TRUE(std::isnan(mixedAddition.z));

  // Test with NaN
  Vec3<double> nanVec = {std::numeric_limits<double>::quiet_NaN(),
                         std::numeric_limits<double>::quiet_NaN(),
                         std::numeric_limits<double>::quiet_NaN()};

  // Any operation with NaN should result in NaN
  auto nanResult = doubleVec1 + nanVec;
  EXPECT_TRUE(std::isnan(nanResult.x));
  EXPECT_TRUE(std::isnan(nanResult.y));
  EXPECT_TRUE(std::isnan(nanResult.z));
}

// Main function that runs the tests
int main(int argc, char **argv) {
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}