diff options
Diffstat (limited to 'random_fl.c')
| -rw-r--r-- | random_fl.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/random_fl.c b/random_fl.c new file mode 100644 index 0000000..33c88d3 --- /dev/null +++ b/random_fl.c @@ -0,0 +1,129 @@ +/* + (c) 2002:cxc@web.fm + randomix: various PRNG's + code taken from: http://remus.rutgers.edu/%7Erhoads/Code/code.html + let's check it out + */ + +#include <m_pd.h> +#include <stdlib.h> +#include <math.h> + +#define SMALLEST_RANGE .0001 + +#ifndef RAND_MAX +#define RAND_MAX 2147483647 +#endif + +static int makeseed(void); +static int rand_random_fl(int); + +static int makeseed(void) +{ + static unsigned int random1_nextseed = 1489853723; + random1_nextseed = random1_nextseed * 435898247 + 938284287; + return (random1_nextseed & 0x7fffffff); +} + +static int rand_random_fl(seed) { + int q; + double state; + + /* The following parameters are recommended settings based on research + uncomment the one you want. */ + + double a = 1389796, m = RAND_MAX; + /* static double a = 950975, m = 2147483647; */ + /* static double a = 3467255, m = 21474836472; */ + /* static double a = 657618, m = 4294967291; */ + /* static double a = 93167, m = 4294967291; */ + /* static double a = 1345659, m = 4294967291; */ + + state = seed; + state *= a; + q = state / m; + state -= q*m; + return state; +} + +/* -------------------------- random_fl ------------------------------ */ +/* An improved (faster) implementation of the Linear Congruential Generator. Has parameters for 6 separate */ +/* linear congruence formulas. These formulas are different than those above because the previous formulas won't work */ +/* correctly in this implementation. Also, this method only works if your floating point mantissa has at least 53 bits. */ + +/* linear congruential generator. Generator x[n+1] = a * x[n] mod m */ +/* works if your floating pt. mantissa has at least 53 bits. + faster than other versions */ + +static t_class *random_fl_class; + +typedef struct _random_fl +{ + t_object x_obj; + t_float x_f; // lower limit + t_float x_g; // upper limit + unsigned int x_state; // current seed +} t_random_fl; + +static void *random_fl_new(t_floatarg f, t_floatarg g) +{ + t_random_fl *x = (t_random_fl *)pd_new(random_fl_class); + x->x_f = (f) ? f : 0; + x->x_g = (g) ? g : RAND_MAX; + //post("cxc/randomix.c: lolim: %f - %f, uplim: %f - %f", x->x_f, f, x->x_g, g); + x->x_state = makeseed(); + inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("fl1")); + inlet_new(&x->x_obj, &x->x_obj.ob_pd, &s_float, gensym("fl2")); + outlet_new(&x->x_obj, &s_float); + return (x); +} + +void random_fl_bang(t_random_fl *x) +{ + int n = x->x_f; + int q; + double nval; + double m; + + m = RAND_MAX; + x->x_state = rand_random_fl(x->x_state); + nval = ((x->x_state / m) * (double)(x->x_g - x->x_f) + (double)x->x_f); + outlet_float(x->x_obj.ob_outlet, nval); +} + +void random_fl_low(t_random_fl *x, t_floatarg f) +{ + if(f >= x->x_g) { + post("cxc/randomix.c: lower larger than upper, setting to upper - %f = %f", + SMALLEST_RANGE, + x->x_g - SMALLEST_RANGE); + x->x_f = x->x_g - SMALLEST_RANGE; + } else x->x_f = f; +} + +void random_fl_upp(t_random_fl *x, t_floatarg f) +{ + if(f <= x->x_f) { + post("cxc/randomix.c: upper smaller than lower, setting to lower + %f = %f", + SMALLEST_RANGE, + x->x_f + SMALLEST_RANGE); + x->x_g = x->x_f + SMALLEST_RANGE; + } else x->x_g = f; +} + +static void random_fl_seed(t_random_fl *x, float f, float glob) +{ + x->x_state = f; +} + +void random_fl_setup(void) +{ + random_fl_class = class_new(gensym("random_fl"), (t_newmethod)random_fl_new, 0, + sizeof(t_random_fl), 0, A_DEFFLOAT, A_DEFFLOAT, 0); + class_addbang(random_fl_class, random_fl_bang); + class_addmethod(random_fl_class, (t_method)random_fl_low, gensym("fl1"), A_FLOAT, 0); + class_addmethod(random_fl_class, (t_method)random_fl_upp, gensym("fl2"), A_FLOAT, 0); + + class_addmethod(random_fl_class, (t_method)random_fl_seed, + gensym("seed"), A_FLOAT, 0); +} |