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#ifndef __CGLA_H
#define __CGLA_H

#ifndef OLD_C_HEADERS
#include <cmath>
#include <climits>
#include <cassert>
#else
#include <math.h>
#include <limits.h>
#include <assert.h>
#endif

#include <algorithm>

#ifndef M_PI
#define M_PI 3.14159265358979323846
#define M_PI_2 1.57079632679489661923
#endif

namespace CGLA {

        /** Numerical constant representing something large.
                        value is a bit arbitrary */
        const double BIG=10e+30;

        /** Numerical constant represents something extremely small.
                        value is a bit arbitrary */
        const double MINUTE=10e-30;

        /** Numerical constant represents something very small.
                        value is a bit arbitrary */
        const double TINY=3e-7;
        
        /** Numerical constant represents something small.
                        value is a bit arbitrary */
        const double SMALL=10e-2;

        const double SQRT3=sqrt(3.0);

        /// Useful enum that represents coordiante axes.
        enum Axis {XAXIS=0,YAXIS=1,ZAXIS=2};

        template<class Scalar>
        Scalar s_min(Scalar a, Scalar b)
        {
                return a<b ? a : b;
        }

        template<class Scalar>
        Scalar s_max(Scalar a, Scalar b)
        {
                return a>b ? a : b;
        }

        ///Template for a function that squares the argument.
        template <class Scalar>
        inline Scalar sqr(Scalar x) {///
                return x*x;}
        
        /// Scalaremplate for a function that returns the cube of the argument.
        template <class Scalar>
        inline Scalar qbe(Scalar x) {///
                return x*x*x;}

        template <class Scalar>
        inline bool is_zero(Scalar x)   {return (x > -MINUTE && x < MINUTE);}

        template <class Scalar>
        inline bool is_tiny(Scalar x)   {return (x > -TINY && x < TINY);}

        /** What power of 2 ?. if x is the argument, find the largest 
                        y so that 2^y <= x */
        inline int two_to_what_power(int x) 
        {
                if (x<1) 
                        return -1;
                int i = 0;
                while (x != 1) {x>>=1;i++;}
                return i;
        }

#ifdef __sgi
        inline int round(float x) {return int(rint(x));}
#else
        inline int round(float x) {return int(x+0.5);}
#endif

        template<class T>
        inline T sign(T x) {return x>=T(0) ? 1 : -1;}


        template<class T>
        inline T int_pow(T x, int k) 
        {
                T y = static_cast<T>(1);
                for(int i=0;i<k;++i)
                        y *= x;
                return y;
        }

        
}

#endif