frac.h

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/*
 * Copyright (C) 2018 Eistec AB
 *
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */
 
#ifndef FRAC_H
#define FRAC_H
 
#include <stdint.h>
 
#ifdef __cplusplus
extern "C" {
#endif
 
typedef struct {
    uint32_t frac; 
    uint8_t shift; 
} frac_t;
 
uint32_t gcd32(uint32_t u, uint32_t v);
 
void frac_init(frac_t *frac, uint32_t num, uint32_t den);
 
static inline uint32_t frac_scale(const frac_t *frac, uint32_t x)
{
    uint32_t scaled = ((uint64_t)frac->frac * x) >> frac->shift;
    return scaled;
}
 
#ifdef __cplusplus
}
#endif
#endif /* FRAC_H */