Pink noise from CLI

pink_main.c

/* depend: Tom Merchant's Voss-McCartney pink-noise approximation algorithm:
 * (https://gist.github.com/tom-merchant/5ced03a0638b06138ee7d11c0c209aa4)
 *
 * output is FLOAT_LE (32-bit)
 * Project Crew™ 2/4/2026
 */

#include <stdio.h>
#include <stdlib.h>
#include <curses.h>

#include "pinknoise.c"

int
main(int argc, char *argv[])
{
    pink osc;
    float out[1];
    int ccc, cc, c, d, time = 0;

    if(argc > 1)                        /* arg parsing */
    {
        time = atoi(argv[1]);
        fprintf(stderr, "%i\n", time);
        if(time == 0)
        {
            d = 0;                      /* sets infinite for loop */
            time = 1;
        }else if(time < 0)
        {
            time ^= -1;                 /* flip sign */
            time++;
            d = 1;                      /* regular for loop */
        }else
        {
            d = 1;
        }
    }else
    {
        d = 0;                          /* no args so infinite loop */
        time = 1;
    }
    fprintf(stderr, "%i, %i\n", time, d);

    init_pink_noise_gen(&osc);    
    //out[0] = &osc.out;
    for(ccc = 0; ccc < time; ccc += d)
    {
        for(cc = 0; cc < 100; cc++)
        {
            for(c = 0; c < 441; c++)      /* the Joy of division */
            {
                out[0] = pink_noise_next(&osc);
                /*
                if(out[0] > 0)
                    out[0] -= 0.4;
                else
                    out[0] += 0.4;*/
                fwrite(out, sizeof(float), 1, stdout);
                //if(out[0] >= 1)
                //    printf("%f\n", out[0]);
                //printf("%f\n", osc.out);
            }
        }
    //puts("");
    }
}

pinknoise.c

/*
 * A very simple and very fast implementation of the Voss-McCartney pink-noise approximation algorithm
 * using a middle square weyl PRNG and a look-up table for octave-sequencing
 *
 * LICENSE:
 *
 * Copyright 2020 Thomas Merchant
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated
 * documentation files (the "Software"), to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of
 * the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO
 * THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
 * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE
 *
 */

#include <stdio.h>
#include <stdint.h>
#include <string.h>

typedef struct
middle_square_weyl
{
    uint64_t s;
    uint64_t x;
    uint64_t w;
} middle_square_weyl;

int32_t
next_int(middle_square_weyl* rand)
{
    rand->x *= rand->x;
    rand->x += (rand->w += rand->s);
    return rand->x = (rand->x >> 32u) | (rand->x << 32u);
}

typedef struct
pink_noise_gen
{
    middle_square_weyl rand;
    float out;
    float octave_hold_vals[9];
    uint8_t counter;
} pink;

void
init_pink_noise_gen(pink *osc)
{
    osc->rand.s = 0x2252e7cd98846fdd;
    osc->rand.x = 0;
    osc->rand.w = 0;
    osc->counter = 0;

    memset(osc->octave_hold_vals, 0, 9*4);
    osc->out = 0;
}

uint8_t trailing_zeros[256] = {8,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,7,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,};

float
pink_noise_next(pink *osc)
{
    uint8_t octave = trailing_zeros[osc->counter];

    osc->out -= osc->octave_hold_vals[octave];
    osc->octave_hold_vals[octave] = (float)next_int(&osc->rand) / (float)INT32_MAX;
    osc->octave_hold_vals[octave] /= (float)(10-octave);
    osc->out += osc->octave_hold_vals[octave];

    osc->counter++;

    return osc->out;
}