raze-gles/source/common/thirdparty/math/cmath.h
2020-04-12 08:30:39 +02:00

149 lines
No EOL
3 KiB
C++

#ifndef __CMATH_H
#define __CMATH_H
#include "xs_Float.h"
#define USE_CUSTOM_MATH // we want repreducably reliable results, even at the cost of performance
#define USE_FAST_MATH // use faster table-based sin and cos variants with limited precision (sufficient for Doom gameplay)
extern"C"
{
double c_asin(double);
double c_acos(double);
double c_atan(double);
double c_atan2(double, double);
double c_sin(double);
double c_cos(double);
double c_tan(double);
double c_cot(double);
double c_sqrt(double);
double c_sinh(double);
double c_cosh(double);
double c_tanh(double);
double c_exp(double);
double c_log(double);
double c_log10(double);
double c_pow(double, double);
}
// This uses a sine table with linear interpolation
// For in-game calculations this is precise enough
// and this code is more than 10x faster than the
// Cephes sin and cos function.
struct FFastTrig
{
static const int TBLPERIOD = 8192;
static const int BITSHIFT = 19;
static const int REMAINDER = (1 << BITSHIFT) - 1;
float sinetable[2049];
double sinq1(unsigned);
public:
FFastTrig();
double sin(unsigned);
double cos(unsigned);
};
extern FFastTrig fasttrig;
// This must use xs_Float to guarantee proper integer wraparound.
#define DEG2BAM(f) ((unsigned)xs_CRoundToInt((f) * (0x40000000/90.)))
#define RAD2BAM(f) ((unsigned)xs_CRoundToInt((f) * (0x80000000/3.14159265358979323846)))
inline double fastcosdeg(double v)
{
return fasttrig.cos(DEG2BAM(v));
}
inline double fastsindeg(double v)
{
return fasttrig.sin(DEG2BAM(v));
}
inline double fastcos(double v)
{
return fasttrig.cos(RAD2BAM(v));
}
inline double fastsin(double v)
{
return fasttrig.sin(RAD2BAM(v));
}
// these are supposed to be local to this file.
#undef DEG2BAM
#undef RAD2BAM
inline double sindeg(double v)
{
#ifdef USE_CUSTOM_MATH
return c_sin(v * (3.14159265358979323846 / 180.));
#else
return sin(v * (3.14159265358979323846 / 180.));
#endif
}
inline double cosdeg(double v)
{
#ifdef USE_CUSTOM_MATH
return c_cos(v * (3.14159265358979323846 / 180.));
#else
return cos(v * (3.14159265358979323846 / 180.));
#endif
}
#ifndef USE_CUSTOM_MATH
#define g_asin asin
#define g_acos acos
#define g_atan atan
#define g_atan2 atan2
#define g_sin sin
#define g_cos cos
#define g_sindeg sindeg
#define g_cosdeg cosdeg
#define g_tan tan
#define g_cot cot
#define g_sqrt sqrt
#define g_sinh sinh
#define g_cosh cosh
#define g_tanh tanh
#define g_exp exp
#define g_log log
#define g_log10 log10
#define g_pow pow
#else
#define g_asin c_asin
#define g_acos c_acos
#define g_atan c_atan
#define g_atan2 c_atan2
#ifndef USE_FAST_MATH
#define g_sindeg sindeg
#define g_cosdeg cosdeg
#define g_sin c_sin
#define g_cos c_cos
#else
#define g_sindeg fastsindeg
#define g_cosdeg fastcosdeg
#define g_sin fastsin
#define g_cos fastcos
#endif
#define g_tan c_tan
#define g_cot c_cot
#define g_sqrt c_sqrt
#define g_sinh c_sinh
#define g_cosh c_cosh
#define g_tanh c_tanh
#define g_exp c_exp
#define g_log c_log
#define g_log10 c_log10
#define g_pow c_pow
#endif
#endif