math.h

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#ifndef BJ_MATH_H
#define BJ_MATH_H
 
#include <math.h>
#include <float.h>

 
#if defined(BJ_API_LONG_DOUBLE)
    typedef long double bj_real;
    #define BJ_F(x) x##L
    #define BJ_EPSILON (LDBL_EPSILON)
#elif defined(BJ_API_FLOAT64)
    typedef double bj_real;
    #define BJ_F(x) x
    #define BJ_EPSILON (DBL_EPSILON)
#else
    typedef float bj_real;
    #define BJ_F(x) x##f
    #define BJ_EPSILON (FLT_EPSILON)
#endif

#define BJ_FI(x) BJ_F(1.0) / BJ_F(x)

#define BJ_FZERO (BJ_F(0.0))



#define BJ_PI_F   (3.14159265358979323846f)
#define BJ_TAU_F  (6.28318530717958647692f)
#define BJ_PI_D   (3.14159265358979323846264338327950288)
#define BJ_TAU_D  (6.28318530717958647692528676655900576)
#define BJ_PI_L   (3.141592653589793238462643383279502884L)
#define BJ_TAU_L  (6.283185307179586476925286766559005768L)
#define BJ_PI     (BJ_F(3.141592653589793238462643383279502884))
#define BJ_TAU    (BJ_F(6.283185307179586476925286766559005768))


 
#define bj_absf       fabsf      
#define bj_acosf      acosf      
#define bj_atan2f     atan2f     
#define bj_copysignf  copysignf  
#define bj_cosf       cosf       
#define bj_expf       expf       
#define bj_floorf     floorf     
#define bj_fmodf      fmodf      
#define bj_logf       logf       
#define bj_maxf       fmaxf      
#define bj_minf       fminf      
#define bj_powf       powf       
#define bj_roundf     roundf     
#define bj_sinf       sinf       
#define bj_sqrtf      sqrtf      
#define bj_tanf       tanf       


 
#define bj_absd       fabs       
#define bj_acosd      acos       
#define bj_atan2d     atan2      
#define bj_copysignd  copysign   
#define bj_cosd       cos        
#define bj_expd       exp        
#define bj_floord     floor      
#define bj_fmodd      fmod       
#define bj_logd       log        
#define bj_maxd       fmax       
#define bj_mind       fmin       
#define bj_powd       pow        
#define bj_roundd     round      
#define bj_sind       sin        
#define bj_sqrtd      sqrt       
#define bj_tand       tan        


 
#define bj_absl       fabsl      
#define bj_acosl      acosl      
#define bj_atan2l     atan2l     
#define bj_copysignl  copysignl  
#define bj_cosl       cosl       
#define bj_expl       expl       
#define bj_floorl     floorl     
#define bj_fmodl      fmodl      
#define bj_logl       logl       
#define bj_maxl       fmaxl      
#define bj_minl       fminl      
#define bj_powl       powl       
#define bj_roundl     roundl     
#define bj_sinl       sinl       
#define bj_sqrtl      sqrtl      
#define bj_tanl       tanl       


 
#if defined(BJ_API_LONG_DOUBLE)
    #define bj_abs       bj_absl
    #define bj_acos      bj_acosl
    #define bj_atan2     bj_atan2l
    #define bj_copysign  bj_copysignl
    #define bj_cos       bj_cosl
    #define bj_exp       bj_expl
    #define bj_floor     bj_floorl
    #define bj_fmod      bj_fmodl
    #define bj_log       bj_logl
    #define bj_max       bj_maxl
    #define bj_min       bj_minl
    #define bj_pow       bj_powl
    #define bj_round     bj_roundl
    #define bj_sin       bj_sinl
    #define bj_sqrt      bj_sqrtl
    #define bj_tan       bj_tanl
#elif defined(BJ_API_FLOAT64)
    #define bj_abs       bj_absd
    #define bj_acos      bj_acosd
    #define bj_atan2     bj_atan2d
    #define bj_copysign  bj_copysignd
    #define bj_cos       bj_cosd
    #define bj_exp       bj_expd
    #define bj_floor     bj_floord
    #define bj_fmod      bj_fmodd
    #define bj_log       bj_logd
    #define bj_max       bj_maxd
    #define bj_min       bj_mind
    #define bj_pow       bj_powd
    #define bj_round     bj_roundd
    #define bj_sin       bj_sind
    #define bj_sqrt      bj_sqrtd
    #define bj_tan       bj_tand
#else
    #define bj_abs       bj_absf      
    #define bj_acos      bj_acosf     
    #define bj_atan2     bj_atan2f    
    #define bj_copysign  bj_copysignf 
    #define bj_cos       bj_cosf      
    #define bj_exp       bj_expf      
    #define bj_floor     bj_floorf    
    #define bj_fmod      bj_fmodf     
    #define bj_log       bj_logf      
    #define bj_max       bj_maxf      
    #define bj_min       bj_minf      
    #define bj_pow       bj_powf      
    #define bj_round     bj_roundf    
    #define bj_sin       bj_sinf      
    #define bj_sqrt      bj_sqrtf     
    #define bj_tan       bj_tanf      
#endif



static inline bj_real bj_clamp(bj_real x, bj_real lo, bj_real hi) {
    return (x < lo) ? lo : (x > hi) ? hi : x;
}

static inline bj_real bj_step(bj_real edge, bj_real x) {
    return (x < edge) ? BJ_FZERO : BJ_F(1.0);
}

static inline bj_real bj_smoothstep(bj_real e0, bj_real e1, bj_real x) {
    bj_real t = (x - e0) / (e1 - e0);
    t = (t < BJ_FZERO) ? BJ_FZERO : (t > BJ_F(1.0)) ? BJ_F(1.0) : t;
    return t * t * (BJ_F(3.0) - BJ_F(2.0) * t);
}

static inline bj_real bj_fract(bj_real x) {
    return x - bj_floor(x);
}

static inline bj_real bj_mod(bj_real x, bj_real y) {
    bj_real m = bj_fmod(x, y);
    if (m < BJ_FZERO) m += (y < BJ_FZERO) ? -y : y;
    return m;
}



static inline int  bj_real_eq (bj_real a, bj_real b) { return bj_abs(a - b) <= BJ_EPSILON; }

static inline int  bj_real_neq(bj_real a, bj_real b) { return !bj_real_eq(a, b); }

static inline int  bj_real_lt (bj_real a, bj_real b) { return (b - a) >  BJ_EPSILON; }

static inline int  bj_real_gt (bj_real a, bj_real b) { return (a - b) >  BJ_EPSILON; }

static inline int  bj_real_lte(bj_real a, bj_real b) { return !bj_real_gt(a, b); }

static inline int  bj_real_gte(bj_real a, bj_real b) { return !bj_real_lt(a, b); }

static inline int  bj_real_cmp(bj_real a, bj_real b) { return bj_real_lt(a,b) ? -1 : (bj_real_gt(a,b) ? 1 : 0); }



static inline bj_real bj_real_relative_scale(bj_real a, bj_real b) {
    return bj_max(BJ_F(1.0), bj_max(bj_abs(a), bj_abs(b)));
}

static inline int  bj_real_eq_rel (bj_real a, bj_real b) { bj_real s = bj_real_relative_scale(a,b); return bj_abs(a - b) <= (BJ_EPSILON * s); }

static inline int  bj_real_neq_rel(bj_real a, bj_real b) { return !bj_real_eq_rel(a, b); }

static inline int  bj_real_lt_rel (bj_real a, bj_real b) { bj_real s = bj_real_relative_scale(a,b); return (b - a) >  (BJ_EPSILON * s); }

static inline int  bj_real_gt_rel (bj_real a, bj_real b) { bj_real s = bj_real_relative_scale(a,b); return (a - b) >  (BJ_EPSILON * s); }

static inline int  bj_real_lte_rel(bj_real a, bj_real b) { return !bj_real_gt_rel(a, b); }

static inline int  bj_real_gte_rel(bj_real a, bj_real b) { return !bj_real_lt_rel(a, b); }

static inline int  bj_real_cmp_rel(bj_real a, bj_real b) { return bj_real_lt_rel(a,b) ? -1 : (bj_real_gt_rel(a,b) ? 1 : 0); }



static inline int   bj_real_is_zero(bj_real x) { return bj_abs(x) <= BJ_EPSILON; }

static inline int   bj_real_is_zero_scaled(bj_real x, bj_real scale) {
    bj_real s = bj_max(BJ_F(1.0), bj_abs(scale));
    return bj_abs(x) <= (BJ_EPSILON * s);
}

static inline bj_real bj_real_snap_zero(bj_real x) { return bj_real_is_zero(x) ? BJ_FZERO : x; }

static inline bj_real bj_real_snorm_safe(bj_real x, bj_real len) { return bj_real_is_zero(len) ? BJ_FZERO : (x / len); }


 
#endif /* BJ_MATH_H */