Subversion Repositories gelsvn

Rev

Rev 5 | Go to most recent revision | Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 bj 1 
#ifndef __CGLA_H
2 
#define __CGLA_H
3 
 
4 
#ifndef OLD_C_HEADERS
5 
#include <cmath>
6 
#include <climits>
7 
#include <cassert>
8 
#else
9 
#include <math.h>
10 
#include <limits.h>
11 
#include <assert.h>
12 
#endif
13 
 
14 
#include <algorithm>
15 
 
16 
#ifndef M_PI
17 
#define M_PI 3.14159265358979323846
18 
#define M_PI_2 1.57079632679489661923
19 
#endif
20 
 
21 
namespace CGLA {
22 
 
23 
	/** Numerical constant representing something large.
24 
			value is a bit arbitrary */
25 
	const float BIG=10e+30f;
26 
 
27 
	/** Numerical constant represents something extremely small.
28 
			value is a bit arbitrary */
29 
	const float MINUTE=10e-30f;
30 
 
31 
	/** Numerical constant represents something very small.
32 
			value is a bit arbitrary */
33 
	const float TINY=3e-7f;
34 
 
35 
	/** Numerical constant represents something small.
36 
			value is a bit arbitrary */
37 
	const float SMALL=10e-2f;
38 
 
39 
	const float SQRT3=sqrt(3.0f);
40 
 
41 
	/// Useful enum that represents coordiante axes.
42 
	enum Axis {XAXIS=0,YAXIS=1,ZAXIS=2};
43 
 
44 
	template<class Scalar>
45 
	Scalar s_min(Scalar a, Scalar b)
46 
	{
47 
		return a<b ? a : b;
48 
	}
49 
 
50 
	template<class Scalar>
51 
	Scalar s_max(Scalar a, Scalar b)
52 
	{
53 
		return a>b ? a : b;
54 
	}
55 
 
56 
	///Template for a function that squares the argument.
57 
	template <class Scalar>
58 
	inline Scalar sqr(Scalar x) {///
59 
		return x*x;}
60 
 
61 
	/// Scalaremplate for a function that returns the cube of the argument.
62 
	template <class Scalar>
63 
	inline Scalar qbe(Scalar x) {///
64 
		return x*x*x;}
65 
 
66 
	template <class Scalar>
67 
	inline bool is_zero(Scalar x)	{return (x > -MINUTE && x < MINUTE);}
68 
 
69 
	template <class Scalar>
70 
	inline bool is_tiny(Scalar x)	{return (x > -TINY && x < TINY);}
71 
 
72 
	/** What power of 2 ?. if x is the argument, find the largest
73 
			y so that 2^y <= x */
74 
	inline int two_to_what_power(int x)
75 
	{
76 
		if (x<1)
77 
			return -1;
78 
		int i = 0;
79 
		while (x != 1) {x>>=1;i++;}
80 
		return i;
81 
	}
82 
 
83 
#ifdef __sgi
84 
	inline int round(float x) {return int(rint(x));}
85 
#else
86 
	inline int round(float x) {return int(x+0.5);}
87 
#endif
88 
 
89 
	template<class T>
90 
	inline T sign(T x) {return x>=T(0) ? 1 : -1;}
91 
 
92 
 
93 
	template<class T>
94 
	inline T int_pow(T x, int k)
95 
	{
96 
		T y = static_cast<T>(1);
97 
		for(int i=0;i<k;++i)
98 
			y *= x;
99 
		return y;
100 
	}
101 
 
102 
 
103 
}
104 
 
105 
#endif