/*
 * Copyright 2005 Sandia Corporation.
 * Under the terms of Contract DE-AC04-94AL85000, there is a non-exclusive
 * license for use of this work by or on behalf of the
 * U.S. Government. Redistribution and use in source and binary forms, with
 * or without modification, are permitted provided that this Notice and any
 * statement of authorship are reproduced on all copies.
 */
#include "vtkMath.h"
#include "vtkMathConfigure.h"

#include <limits>

#ifndef ABS
#define ABS(x) ((x) < 0 ? -(x) : (x))
#endif

template<class A>
bool fuzzyCompare1DWeak(A a, A b)
{
  return ABS(a - b) < .0001;
}

template<class A>
bool fuzzyCompare1D(A a, A b)
{
  return ABS(a - b) < std::numeric_limits<A>::epsilon();
}

template<class A>
bool fuzzyCompare2D(A a[2], A b[2])
{
  return fuzzyCompare1D(a[0], b[0]) &&
         fuzzyCompare1D(a[1], b[1]);
}

template<class A>
bool fuzzyCompare3D(A a[3], A b[3])
{
  return fuzzyCompare1D(a[0], b[0]) &&
         fuzzyCompare1D(a[1], b[1]) &&
         fuzzyCompare1D(a[2], b[2]);
}

//=============================================================================
// Helpful class for storing and using color triples.
class Triple {
public:
  Triple() {};
  Triple(double a, double b, double c) {
    data[0] = a; data[1] = b; data[2] = c;
  }
  const double *operator()() const { return data; }
  double *operator()() { return data; }
  const double &operator[](int i) const { return data[i]; }
  double &operator[](int i) { return data[i]; }
  bool operator==(const Triple &triple) const {
    return *this == triple.data;
  }
  bool operator==(const double *triple) const {
    return (   (this->data[0] - triple[0] <= 0.01*ABS(data[0])+0.02)
            && (this->data[0] - triple[0] >= -0.01*ABS(data[0])-0.02)
            && (this->data[1] - triple[1] <= 0.01*ABS(data[1])+0.02)
            && (this->data[1] - triple[1] >= -0.01*ABS(data[1])-0.02)
            && (this->data[2] - triple[2] <= 0.01*ABS(data[2])+0.02)
            && (this->data[2] - triple[2] >= -0.01*ABS(data[2])-0.02) );
  }
  bool operator!=(const Triple &triple) const {
    return *this != triple.data;
  }
  bool operator!=(const double *triple) const {
    return !(*this == triple);
  }
private:
  double data[3];
};

static ostream &operator<<(ostream &os, const Triple t)
{
  os << t[0] << ", " << t[1] << ", " << t[2];
  return os;
}

//=============================================================================
// Function for comparing colors.  Each value should be equivalent in the
// respective color space.
static int TestColorConvert(const Triple &rgb, const Triple &hsv,
                            const Triple &xyz, const Triple &lab);

// Function for comparing special doubles like Inf and NaN.
#define TestSpecialDoubles(value, inftest, nantest) \
  TestSpecialDoublesReal(value, #value, inftest, nantest)
static int TestSpecialDoublesReal(double value, const char *name,
                                  bool inftest, bool nantest);

int TestMath(int,char *[])
{
  // Test ProjectVector float
  {
  std::cout << "Testing ProjectVector float" << std::endl;
  float a[3] = {2,-5,0};
  float b[3] = {5,1,0};
  float projection[3];
  float correct[3] = {25.f/26.f, 5.f/26.f, 0.f};
  vtkMath::ProjectVector(a,b,projection);
  if(!fuzzyCompare3D(projection,correct))
    {
    std::cerr << "ProjectVector failed! Should be (25./26., 5./26., 0) but it is ("
                  <<projection[0] << " " << projection[1] << " " << projection[2] << ")" << std::endl;
    return EXIT_FAILURE;
    }
  }

  // Test ProjectVector2D float
  {
  std::cout << "Testing ProjectVector2D float" << std::endl;
  float a[2] = {2,-5};
  float b[2] = {5,1};
  float projection[2];
  float correct[3] = {25.f/26.f, 5.f/26.f};
  vtkMath::ProjectVector2D(a,b,projection);
  if(!fuzzyCompare2D(projection,correct))
    {
    std::cerr << "ProjectVector failed! Should be (25./26., 5./26.) but it is ("
                  <<projection[0] << " " << projection[1] << ")" << std::endl;
    return EXIT_FAILURE;
    }
  }

  // Test ProjectVector double
  {
  std::cout << "Testing ProjectVector double" << std::endl;
  double a[3] = {2,-5,0};
  double b[3] = {5,1,0};
  double projection[3];
  double correct[3] = {25./26., 5./26., 0};
  vtkMath::ProjectVector(a,b,projection);
  if(!fuzzyCompare3D(projection,correct))
    {
    std::cerr << "ProjectVector failed! Should be (25./26., 5./26., 0) but it is ("
                  <<projection[0] << " " << projection[1] << " " << projection[2] << ")" << std::endl;
    return EXIT_FAILURE;
    }
  }

  // Test ProjectVector2D double
  {
  std::cout << "Testing ProjectVector2D double" << std::endl;
  double a[2] = {2,-5};
  double b[2] = {5,1};
  double projection[2];
  double correct[3] = {25./26., 5./26.};
  vtkMath::ProjectVector2D(a,b,projection);
  if(!fuzzyCompare2D(projection,correct))
    {
    std::cerr << "ProjectVector failed! Should be (25./26., 5./26.) but it is ("
                  <<projection[0] << " " << projection[1] << ")" << std::endl;
    return EXIT_FAILURE;
    }
  }

  // Tests for AngleBetweenVectors()
  {
  std::cout << "Testing AngleBetweenVectors" << std::endl;
  std::cout << "  * vector along x-axis, vector along y-axis" << std::endl;
  double v1[3] = { 2.0, 0.0, 0.0 };
  double v2[3] = { 0.0, 5.0, 0.0 };
  double expected = vtkMath::RadiansFromDegrees(90.0);
  double angle = vtkMath::AngleBetweenVectors(v1, v2);
  if (!fuzzyCompare1D(angle, expected))
    {
    vtkGenericWarningMacro("AngleBetweenVectors(2,0,0 , 0,5,0) = " << expected << "  != " << angle);
    return EXIT_FAILURE;
    }

  std::cout << "  * 0,0,0 vector, vector along y-axis" << std::endl;
  v1[0] = 0.0;
  expected = 0.0;
  angle = vtkMath::AngleBetweenVectors(v1, v2);
  if (!fuzzyCompare1D(angle, expected))
    {
    vtkGenericWarningMacro("AngleBetweenVectors(0,0,0 , 0,5,0) = " << expected << "  != " << angle);
    return EXIT_FAILURE;
    }

  std::cout << "  * 0,0,0 vector, 0,0,0 vector" << std::endl;
  v2[1] = 0.0;
  angle = vtkMath::AngleBetweenVectors(v1, v2);
  if (!fuzzyCompare1D(angle, expected))
    {
    vtkGenericWarningMacro("AngleBetweenVectors(0,0,0 , 0,0,0) = " << expected << "  != " << angle);
    return EXIT_FAILURE;
    }

  std::cout << "  * z unit vector, negative z vector" << std::endl;
  v1[2] = 1.0;
  v2[2] = -3.0;
  expected = vtkMath::RadiansFromDegrees(180.0);
  angle = vtkMath::AngleBetweenVectors(v1, v2);
  if (!fuzzyCompare1D(angle, expected))
    {
    vtkGenericWarningMacro("AngleBetweenVectors(z unit , neg z) = " << expected << "  != " << angle);
    return EXIT_FAILURE;
    }
  angle = vtkMath::AngleBetweenVectors(v2, v1);
  if (!fuzzyCompare1D(angle, expected))
    {
    vtkGenericWarningMacro("AngleBetweenVectors(neg z , z unit) = " << expected << "  != " << angle);
    return EXIT_FAILURE;
    }

  std::cout << "  * z unit vector, 4,4,4" << std::endl;
  v2[0] = 4.0;
  v2[1] = 4.0;
  v2[2] = 4.0;
  expected = 0.9553166181245093; // vtkMath::RadiansFromDegrees(54.735610317245346);
  angle = vtkMath::AngleBetweenVectors(v1, v2);
  if (!fuzzyCompare1D(angle, expected))
    {
    vtkGenericWarningMacro("AngleBetweenVectors(z unit , 4,4,4) = " << expected << "  != " << angle);
    return EXIT_FAILURE;
    }

  std::cout << "  * y unit vector, 4,4,4" << std::endl;
  v1[0] = 0.0;
  v1[1] = 1.0;
  v1[2] = 0.0;
  angle = vtkMath::AngleBetweenVectors(v1, v2);
  if (!fuzzyCompare1D(angle, expected))
    {
    vtkGenericWarningMacro("AngleBetweenVectors(y unit , 4,4,4) = " << expected << "  != " << angle);
    return EXIT_FAILURE;
    }

  std::cout << "  * x unit vector, 4,4,4" << std::endl;
  v1[0] = 1.0;
  v1[1] = 0.0;
  v1[2] = 0.0;
  angle = vtkMath::AngleBetweenVectors(v1, v2);
  if (!fuzzyCompare1D(angle, expected))
    {
    vtkGenericWarningMacro("AngleBetweenVectors(x unit , 4,4,4) = " << expected << "  != " << angle);
    return EXIT_FAILURE;
    }
  }

  // Tests for GaussianAmplitude(double,double)
  {
  double gaussianAmplitude = vtkMath::GaussianAmplitude(1.0, 0);
  if (!fuzzyCompare1DWeak(gaussianAmplitude, 0.39894))
    {
    vtkGenericWarningMacro("GaussianAmplitude(1,0) = 0.39894 " <<" != " << gaussianAmplitude);
    return EXIT_FAILURE;
    }
  }

  {
  double gaussianAmplitude = vtkMath::GaussianAmplitude(2.0, 0);
  if (!fuzzyCompare1DWeak(gaussianAmplitude, 0.28209))
    {
    vtkGenericWarningMacro("GaussianAmplitude(2,0) = 0.28209 " <<" != " << gaussianAmplitude);
    return EXIT_FAILURE;
    }
  }

  {
  double gaussianAmplitude = vtkMath::GaussianAmplitude(1.0, 1.0);
  if (!fuzzyCompare1DWeak(gaussianAmplitude, 0.24197))
    {
    vtkGenericWarningMacro("GaussianAmplitude(1,2) = 0.24197 " <<" != " << gaussianAmplitude);
    return EXIT_FAILURE;
    }
  }

  // Tests for GaussianAmplitude(double,double,double)

  {
  double gaussianAmplitude = vtkMath::GaussianAmplitude(0, 1.0, 1.0);
  if (!fuzzyCompare1DWeak(gaussianAmplitude, 0.24197))
    {
    vtkGenericWarningMacro("GaussianAmplitude(0,1,1) = 0.24197 " <<" != " << gaussianAmplitude);
    return EXIT_FAILURE;
    }
  }

  {
  double gaussianAmplitude = vtkMath::GaussianAmplitude(1.0, 1.0, 2.0);
  if (!fuzzyCompare1DWeak(gaussianAmplitude, 0.24197))
    {
    vtkGenericWarningMacro("GaussianAmplitude(1,1,2) = 0.24197 " <<" != " << gaussianAmplitude);
    return EXIT_FAILURE;
    }
  }

  // Tests for GaussianWeight(double,double)
  {
  double gaussianWeight = vtkMath::GaussianWeight(1.0, 0);
  if (!fuzzyCompare1DWeak(gaussianWeight, 1.0))
    {
    vtkGenericWarningMacro("GaussianWeight(1,0) = 1.0 " <<" != " << gaussianWeight);
    return EXIT_FAILURE;
    }
  }

  {
  double gaussianWeight = vtkMath::GaussianWeight(2.0, 0);
  if (!fuzzyCompare1DWeak(gaussianWeight, 1.0))
    {
    vtkGenericWarningMacro("GaussianWeight(2,0) = 1.0 " <<" != " << gaussianWeight);
    return EXIT_FAILURE;
    }
  }

  {
  double gaussianWeight = vtkMath::GaussianWeight(1.0, 1.0);
  if (!fuzzyCompare1DWeak(gaussianWeight, 0.60653))
    {
    vtkGenericWarningMacro("GaussianWeight(1,1) = 0.60653 " <<" != " << gaussianWeight);
    return EXIT_FAILURE;
    }
  }

  // Tests for GaussianWeight(double,double,double)

  {
  double gaussianWeight = vtkMath::GaussianWeight(0, 1.0, 1.0);
  if (!fuzzyCompare1DWeak(gaussianWeight, 0.60653))
    {
    vtkGenericWarningMacro("GaussianWeight(0,1,1) = 0.60653 " <<" != " << gaussianWeight);
    return EXIT_FAILURE;
    }
  }

  {
  double gaussianWeight = vtkMath::GaussianWeight(1.0, 1.0, 2.0);
  if (!fuzzyCompare1DWeak(gaussianWeight, 0.60653))
    {
    vtkGenericWarningMacro("GaussianWeight(1,1,2) = 0.60653 " <<" != " << gaussianWeight);
    return EXIT_FAILURE;
    }
  }

  int testIntValue;

  testIntValue = vtkMath::Factorial(5);
  if ( testIntValue != 120 )
    {
    vtkGenericWarningMacro("Factorial(5) = "<<testIntValue<<" != 120");
    return 1;
    }

  testIntValue = vtkMath::Binomial(8,3);
  if ( testIntValue != 56 )
    {
    vtkGenericWarningMacro("Binomial(8,3) = "<<testIntValue<<" != 56");
    return 1;
    }

  testIntValue = vtkMath::Binomial(5,3);
  if ( testIntValue != 10 )
    {
    vtkGenericWarningMacro("Binomial(5,3) = "<<testIntValue<<" != 10");
    return 1;
    }

  // test CeilLog2
  const static vtkTypeUInt64 testCeilLog2Inputs[7] = {
    0ull, 1ull, 31ull, 32ull, 33ull,
    9223372036854775808ull /* 2^63 */, 18446744073709551615ull /* 2^64-1 */};
  const static int testCeilLog2Outputs[7] = {
    0, 0, 5, 5, 6, 63, 64};
  for (int cl2 = 0; cl2 < 7; cl2++)
    {
    int po2v = vtkMath::CeilLog2(testCeilLog2Inputs[cl2]);
    if (po2v != testCeilLog2Outputs[cl2])
      {
      vtkGenericWarningMacro("CeilLog2(" <<
        testCeilLog2Inputs[cl2] << ") = " << po2v << " != " <<
        testCeilLog2Outputs[cl2]);
      return 1;
      }
    }

  // test is-power-of-two
  const static vtkTypeUInt64 isPowerOfTwoInputs[16] = {
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 255, 256, 257,
    9223372036854775808ull /* 2^63 */, 18446744073709551615ull /* 2^64-1 */};
  const static int isPowerOfTwoOutputs[16] = {
    0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0 };
  for (int ip2 = 0; ip2 < 10; ip2++)
    {
    int ip2v = vtkMath::IsPowerOfTwo(isPowerOfTwoInputs[ip2]);
    if (ip2v ^ isPowerOfTwoOutputs[ip2])
      {
      vtkGenericWarningMacro("IsPowerOfTwo(" <<
        isPowerOfTwoInputs[ip2] << ") = " << ip2v << " != " <<
        isPowerOfTwoOutputs[ip2]);
      return 1;
      }
    }

  // test nearest-power-of-two
  const static int testPowerOfTwoInputs[10] = {
    0, 1, 31, 32, 33, -1, -8, VTK_INT_MAX, 1073741824, 1073741825 };
  const static int testPowerOfTwoOutputs[10] = {
    1, 1, 32, 32, 64, 1, 1, VTK_INT_MIN, 1073741824, VTK_INT_MIN };
  for (int po2 = 0; po2 < 10; po2++)
    {
    int po2v = vtkMath::NearestPowerOfTwo(testPowerOfTwoInputs[po2]);
    if (po2v != testPowerOfTwoOutputs[po2])
      {
      vtkGenericWarningMacro("NearestPowerOfTwo(" <<
        testPowerOfTwoInputs[po2] << ") = " << po2v << " != " <<
        testPowerOfTwoOutputs[po2]);
      return 1;
      }
    }

  // test Floor and Ceil
  const static double fcInputs[19] = {
    0.0, -VTK_DBL_EPSILON, VTK_DBL_EPSILON,
    1.0, 1-VTK_DBL_EPSILON, 1+VTK_DBL_EPSILON,
    2.0, 2-2*VTK_DBL_EPSILON, 2+2*VTK_DBL_EPSILON,
    -1.0, -1-VTK_DBL_EPSILON, -1+VTK_DBL_EPSILON,
    -2.0, -2-2*VTK_DBL_EPSILON, -2+2*VTK_DBL_EPSILON,
    2147483647.0, 2147483647.0-2147483648.0*VTK_DBL_EPSILON,
    -2147483648.0, -2147483648.0+2147483648.0*VTK_DBL_EPSILON };
  const static int floorOutputs[19] = {
    0, -1, 0,  1, 0, 1,  2, 1, 2,  -1, -2, -1,  -2, -3, -2,
    VTK_INT_MAX, VTK_INT_MAX-1,  VTK_INT_MIN, VTK_INT_MIN };
  const static int ceilOutputs[19] = {
    0, 0, 1,  1, 1, 2,  2, 2, 3,  -1, -1, 0,  -2, -2, -1,
    VTK_INT_MAX, VTK_INT_MAX,  VTK_INT_MIN, VTK_INT_MIN+1 };
  for (int fcc = 0; fcc < 19; fcc++)
    {
    int floorOut = vtkMath::Floor(fcInputs[fcc]);
    int ceilOut = vtkMath::Ceil(fcInputs[fcc]);
    if (floorOut != floorOutputs[fcc])
      {
      vtkGenericWarningMacro("Floor(" <<
        fcInputs[fcc] << ") = " << floorOut << " != " <<
        floorOutputs[fcc]);
      return 1;
      }
    if (ceilOut != ceilOutputs[fcc])
      {
      vtkGenericWarningMacro("Ceil(" <<
        fcInputs[fcc] << ") = " << ceilOut << " != " <<
        ceilOutputs[fcc]);
      return 1;
      }
    }

  // Test add, subtract, scalar multiplication.
  double a[3] = {1.0, 2.0, 3.0};
  double b[3] = {0.0, 1.0, 2.0};
  double c[3];
  double ans1[3] = {1.0, 3.0, 5.0};
  double ans2[3] = {1.0, 1.0, 1.0};
  double ans3[3] = {3.0, 6.0, 9.0};
  float af[3] = {1.0f, 2.0f, 3.0f};
  float bf[3] = {0.0f, 1.0f, 2.0f};
  float cf[3];
  float ans1f[3] = {1.0, 3.0, 5.0};
  float ans2f[3] = {1.0, 1.0, 1.0};
  float ans3f[3] = {3.0, 6.0, 9.0};

  vtkMath::Add(a, b, c);
  if (!fuzzyCompare3D(c, ans1))
    {
    vtkGenericWarningMacro("Double addition failed.");
    return 1;
    }
  vtkMath::Subtract(a, b, c);
  if (!fuzzyCompare3D(c, ans2))
    {
    vtkGenericWarningMacro("Double subtraction failed.");
    return 1;
    }
  vtkMath::MultiplyScalar(a, 3.0);
  if (!fuzzyCompare3D(a, ans3))
    {
    vtkGenericWarningMacro("Double scalar multiplication failed.");
    return 1;
    }
  vtkMath::Add(af, bf, cf);
  if (!fuzzyCompare3D(cf, ans1f))
    {
    vtkGenericWarningMacro("Float addition failed.");
	cout << "Result: { " << cf[0] << ", " << cf[1] << ", " << cf[2] << " }" << endl;
    return 1;
    }
  vtkMath::Subtract(af, bf, cf);
  if (!fuzzyCompare3D(cf, ans2f))
    {
    vtkGenericWarningMacro("Float subtraction failed.");
    return 1;
    }
  vtkMath::MultiplyScalar(af, 3.0f);
  if (!fuzzyCompare3D(af, ans3f))
    {
    vtkGenericWarningMacro("Float scalar multiplication failed.");
    return 1;
    }

  // Test color conversion.
  int colorsPassed = 1;

  colorsPassed &= TestColorConvert(Triple(1.0, 1.0, 1.0),             // RGB
                                   Triple(0.0, 0.0, 1.0),   // HSV (H ambiguous)
                                   Triple(0.9505, 1.000, 1.089),      // XYZ
                                   Triple(100.0, 0.0, 0.0));          // CIELAB

  colorsPassed &= TestColorConvert(Triple(0.5, 0.5, 0.0),             // RGB
                                   Triple(1.0/6.0, 1.0, 0.5),         // HSV
                                   Triple(0.165, 0.199, 0.030),       // XYZ
                                   Triple(51.7, -12.90, 56.54));      // CIELAB

  colorsPassed &= TestColorConvert(Triple(0.25, 0.25, 0.5),           // RGB
                                   Triple(2.0/3.0, 0.5, 0.5),         // HSV
                                   Triple(0.078, 0.063, 0.211),       // XYZ
                                   Triple(30.11, 18.49, -36.18));     // CIELAB

  colorsPassed &= TestColorConvert(Triple(0.0, 0.0, 0.0),             // RGB
                                   Triple(0.0, 0.0, 0.0), // HSV (H&S ambiguous)
                                   Triple(0.0, 0.0, 0.0),             // XYZ
                                   Triple(0.0, 0.0, 0.0));            // CIELAB

  if (!colorsPassed)
    {
    return 1;
    }

  if (!TestSpecialDoubles(0, false, false)) return 1;
  if (!TestSpecialDoubles(5, false, false)) return 1;
  if (!TestSpecialDoubles(vtkMath::Inf(), true, false)) return 1;
  if (!TestSpecialDoubles(vtkMath::NegInf(), true, false)) return 1;
  if (!TestSpecialDoubles(vtkMath::Nan(), false, true)) return 1;

  if (!(0 < vtkMath::Inf()))
    {
    vtkGenericWarningMacro(<< "Odd comparison for infinity.");
    return 1;
    }
  if (!(0 > vtkMath::NegInf()))
    {
    vtkGenericWarningMacro(<< "Odd comparison for negative infinity.");
    return 1;
    }

  return 0;
}

static int TestColorConvert(const Triple &rgb, const Triple &hsv,
                            const Triple &xyz, const Triple &lab)
{
  cout << "Ensuring the following colors are consistent: " << endl;
  cout << "   RGB:      " << rgb << endl;
  cout << "   HSV:      " << hsv << endl;
  cout << "   CIE XYZ:  " << xyz << endl;
  cout << "   CIE-L*ab: " << lab << endl;

  Triple result1;
  double *result2;

#define COMPARE(testname, target, dest) \
  if (target != dest)                              \
    { \
    vtkGenericWarningMacro(<< "Incorrect " #testname " conversion.  Got " \
                           << dest << " expected " << target); \
    return 0; \
    }

  // Test conversion between RGB and HSV.
  vtkMath::RGBToHSV(rgb(), result1());
  COMPARE(RGBToHSV, hsv, result1);
  vtkMath::HSVToRGB(hsv(), result1());
  COMPARE(HSVToRGB, rgb, result1);

  result2 = vtkMath::RGBToHSV(rgb());
  COMPARE(RGBToHSV, hsv, result2);
  result2 = vtkMath::HSVToRGB(hsv());
  COMPARE(HSVToRGB, rgb, result2);

  vtkMath::RGBToHSV(rgb[0], rgb[1], rgb[2],
                    &result1[0], &result1[1], &result1[2]);
  COMPARE(RGBToHSV, hsv, result1);
  vtkMath::HSVToRGB(hsv[0], hsv[1], hsv[2],
                    &result1[0], &result1[1], &result1[2]);
  COMPARE(HSVToRGB, rgb, result1);

  // Test conversion between RGB and XYZ.
  vtkMath::RGBToXYZ(rgb(), result1());
  COMPARE(RGBToXYZ, xyz, result1);
  vtkMath::XYZToRGB(xyz(), result1());
  COMPARE(XYZToRGB, rgb, result1);

  result2 = vtkMath::RGBToXYZ(rgb());
  COMPARE(RGBToXYZ, xyz, result2);
  result2 = vtkMath::XYZToRGB(xyz());
  COMPARE(XYZToRGB, rgb, result2);

  vtkMath::RGBToXYZ(rgb[0], rgb[1], rgb[2],
                    &result1[0], &result1[1], &result1[2]);
  COMPARE(RGBToXYZ, xyz, result1);
  vtkMath::XYZToRGB(xyz[0], xyz[1], xyz[2],
                    &result1[0], &result1[1], &result1[2]);
  COMPARE(XYZToRGB, rgb, result1);

  // Test conversion between Lab and XYZ.
  vtkMath::LabToXYZ(lab(), result1());
  COMPARE(LabToXYZ, xyz, result1);
  vtkMath::XYZToLab(xyz(), result1());
  COMPARE(XYZToLab, lab, result1);

  result2 = vtkMath::LabToXYZ(lab());
  COMPARE(LabToXYZ, xyz, result2);
  result2 = vtkMath::XYZToLab(xyz());
  COMPARE(XYZToLab, lab, result2);

  vtkMath::LabToXYZ(lab[0], lab[1], lab[2],
                    &result1[0], &result1[1], &result1[2]);
  COMPARE(LabToXYZ, xyz, result1);
  vtkMath::XYZToLab(xyz[0], xyz[1], xyz[2],
                    &result1[0], &result1[1], &result1[2]);
  COMPARE(XYZToLab, lab, result1);

  // Test conversion between Lab and RGB.
  vtkMath::LabToRGB(lab(), result1());
  COMPARE(LabToRGB, rgb, result1);
  vtkMath::RGBToLab(rgb(), result1());
  COMPARE(RGBToLab, lab, result1);

  result2 = vtkMath::LabToRGB(lab());
  COMPARE(LabToRGB, rgb, result2);
  result2 = vtkMath::RGBToLab(rgb());
  COMPARE(RGBToLab, lab, result2);

  vtkMath::LabToRGB(lab[0], lab[1], lab[2],
                    &result1[0], &result1[1], &result1[2]);
  COMPARE(LabToRGB, rgb, result1);
  vtkMath::RGBToLab(rgb[0], rgb[1], rgb[2],
                    &result1[0], &result1[1], &result1[2]);
  COMPARE(RGBToLab, lab, result1);

  return 1;
}

static int TestSpecialDoublesReal(double value, const char *name,
                                  bool inftest, bool nantest)
{
  cout << "Testing comparison of " << name << " to non-finite values." << endl;
  cout << "  * IsNan test." << endl;
  if (vtkMath::IsNan(value) != static_cast<int>(nantest))
    {
    cout << value << " failed the IsNan test." << endl;
    return 0;
    }
  cout << "  * IsInf test." << endl;
  if (vtkMath::IsInf(value) != static_cast<int>(inftest))
    {
    cout << value << " failed the IsInf test." << endl;
    return 0;
    }
  cout << "  * Tests passed." << endl;

  return 1;
}
