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2 bj 1 
#ifndef __CGLA_H
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#define __CGLA_H
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#ifndef OLD_C_HEADERS
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#include <cmath>
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#include <climits>
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#include <cassert>
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#else
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#include <math.h>
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#include <limits.h>
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#include <assert.h>
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#endif
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#include <algorithm>
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#ifndef M_PI
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#define M_PI 3.14159265358979323846
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#define M_PI_2 1.57079632679489661923
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#endif
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#define CGLA_INIT_VALUE NAN
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namespace CGLA {
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	/** Numerical constant representing something large.
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			value is a bit arbitrary */
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	const double BIG=10e+30;
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	/** Numerical constant represents something extremely small.
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			value is a bit arbitrary */
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	const double MINUTE=10e-30;
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	/** Numerical constant represents something very small.
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			value is a bit arbitrary */
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	const double TINY=3e-7;
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	/** Numerical constant represents something small.
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			value is a bit arbitrary */
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	const double SMALL=10e-2;
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	const double SQRT3=sqrt(3.0);
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	/// Useful enum that represents coordiante axes.
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	enum Axis {XAXIS=0,YAXIS=1,ZAXIS=2};
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	template<class Scalar>
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	Scalar s_min(Scalar a, Scalar b)
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	{
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		return a<b ? a : b;
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	}
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	template<class Scalar>
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	Scalar s_max(Scalar a, Scalar b)
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	{
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		return a>b ? a : b;
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	}
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	///Template for a function that squares the argument.
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	template <class Scalar>
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	inline Scalar sqr(Scalar x) {///
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		return x*x;}
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	/// Scalaremplate for a function that returns the cube of the argument.
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	template <class Scalar>
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	inline Scalar qbe(Scalar x) {///
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		return x*x*x;}
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	template <class Scalar>
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	inline bool is_zero(Scalar x)	{return (x > -MINUTE && x < MINUTE);}
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	template <class Scalar>
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	inline bool is_tiny(Scalar x)	{return (x > -TINY && x < TINY);}
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	/** What power of 2 ?. if x is the argument, find the largest
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			y so that 2^y <= x */
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	inline int two_to_what_power(int x)
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	{
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		if (x<1)
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			return -1;
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		int i = 0;
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		while (x != 1) {x>>=1;i++;}
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		return i;
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	}
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#ifdef __sgi
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	inline int round(float x) {return int(rint(x));}
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#else
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	inline int round(float x) {return int(x+0.5);}
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#endif
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	template<class T>
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	inline T sign(T x) {return x>=T(0) ? 1 : -1;}
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	template<class T>
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	inline T int_pow(T x, int k)
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	{
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		T y = static_cast<T>(1);
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		for(int i=0;i<k;++i)
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			y *= x;
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		return y;
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	}
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}
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#endif