// Magic Software, Inc.
// http://www.magic-software.com
// Copyright (c) 2000, 2001.  All Rights Reserved
//
// Source code from Magic Software is supplied under the terms of a license
// agreement and may not be copied or disclosed except in accordance with the
// terms of that agreement.  The various license agreements may be found at
// the Magic Software web site.  This file is subject to the license
//
// FREE SOURCE CODE
// http://www.magic-software.com/License/free.pdf

#ifndef MGCMATH_H
#define MGCMATH_H

#include "MagicFMLibType.h"
#include "MgcRTLib.h"



namespace Mgc {

    typedef double Real;

class MAGICFM Math
{
public:
    // Return -1 if the input is negative, 0 if the input is zero, and +1
    // if the input is positive.
    static int Sign (int iValue);
    static Real Sign (Real fValue);

    // Just computes fValue*fValue.
    static Real Sqr (Real fValue);

    // Generate a random number in [0,1).  The random number generator may
    // be seeded by a first call to UnitRandom with a positive seed.
    static Real UnitRandom (Real fSeed = 0.0f);

    // Generate a random number in [-1,1).  The random number generator may
    // be seeded by a first call to SymmetricRandom with a positive seed.
    static Real SymmetricRandom (Real fSeed = 0.0f);

    // Generate a random number in [min,max).  The random number generator may
    // be seeded by a first call to IntervalRandom with a positive seed.
    static Real IntervalRandom (Real fMin, Real fMax, Real fSeed = 0.0f);

    // Fast evaluation of sin(angle) by polynomial approximations.  The angle
    // must be in [0,pi/2].  The maximum absolute error is about 1.7e-04 for
    // FastSin0 and about 2.3e-09 for FastSin1.  The speed up is about 2 for
    // FastSin0 and about 1.5 for FastSin1.
    static Real FastSin0 (Real fAngle);
    static Real FastSin1 (Real fAngle);

    // Fast evaluation of cos(angle) by polynomial approximations.  The angle
    // must be in [0,pi/2].  The maximum absolute error is about 1.2e-03 for
    // FastCos0 and about 2.3e-09 for FastCos1.  The speed up is about 2 for
    // FastCos0 and about 1.5 for FastCos1.
    static Real FastCos0 (Real fAngle);
    static Real FastCos1 (Real fAngle);

    // Fast evaluation of tan(angle) by polynomial approximations.  The angle
    // must be in [0,pi/4].  The maximum absolute error is about 8.1e-04 for
    // FastTan0 and about 1.9e-08 for FastTan1.  The speed up is about 2.5 for
    // FastTan0 and about 1.75 for FastTan1.
    static Real FastTan0 (Real fAngle);
    static Real FastTan1 (Real fAngle);

    // Fast evaluation of asin(value) by a sqrt times a polynomial.  The value
    // must be in [0,1].  The maximum absolute error is about 6.8e-05 and the
    // speed up is about 2.5.
    static Real FastInvSin (Real fValue);

    // Fast evaluation of acos(value) by a sqrt times a polynomial.  The value
    // must be in [0,1].  The maximum absolute error is about 6.8e-05 and the
    // speed up is about 2.5.
    static Real FastInvCos (Real fValue);

    // Fast evaluation of atan(value) by polynomial approximations.  The value
    // must be in [-1,1].  The maximum absolute error is about 1.2e-05 for
    // FastInvTan0 and about 1.43-08 for FastInvTan1.  The speed up is about
    // 2.2 for FastInvTan0 and about 1.5 for FastInvTan1.
    static Real FastInvTan0 (Real fValue);
    static Real FastInvTan1 (Real fValue);

    // Wrappers for acos and asin, but the input value is clamped to [-1,1]
    // to avoid silent returns of NaN.
    static Real ACos (Real fValue);
    static Real ASin (Real fValue);

    // Wrapper for 1/sqrt to allow a fast implementation to replace it at a
    // later date.
    static Real InvSqrt (Real fValue);

    // Wrappers to hide 'double foo(double)' versus 'float foof(float)'.
    static Real ATan (Real fValue);
    static Real ATan2 (Real fY, Real fX);
    static Real Ceil (Real fValue);
    static Real Cos (Real fValue);
    static Real Exp (Real fValue);
    static Real FAbs (Real fValue);
    static Real Floor (Real fValue);
    static Real Log (Real fValue);
    static Real Pow (Real kBase, Real kExponent);
    static Real Sin (Real fValue);
    static Real Sqrt (Real fValue);

    // common constants
    static const Real MAX_REAL;
    static const Real PI;
    static const Real TWO_PI;
    static const Real HALF_PI;
    static const Real INV_TWO_PI;
    static const Real DEG_TO_RAD;
    static const Real RAD_TO_DEG;
};

#include "MgcMath.inl"

} // namespace Mgc

#endif
