ch_math_utils.h

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#ifndef CH_MATH_UTILS_H_
#define CH_MATH_UTILS_H_
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include <stdio.h>
#include <math.h>
#include <stdint.h>
 
#define FRACT_BITS 16
 
#define INT2FIXED(x)   ((x) << FRACT_BITS)
#define FLOAT2FIXED(x) ((fixed_t)((x) * (1 << FRACT_BITS)))
 
#define FIXED2INT(x)   ((x) >> FRACT_BITS)
#define FIXED2FLOAT(x) (((float)(x)) / (1 << FRACT_BITS))
 
#define FIXEDDIV(x, y) ((fixed_t)(((uint64_t)(x) << FRACT_BITS) / (y)))
#define FIXEDMUL(x, y) ((fixed_t)(((x) >> (FRACT_BITS / 2)) * ((y) >> (FRACT_BITS / 2))))
 
#define FIXED_PI 0x3243FU
 
#define INV_LOG2_E_Q1DOT31 0x58b90bfcU  // Inverse log base 2 of e, Q1.31 format
 
#define Q31_TO_Q16_SHIFT_BITS 15  // Shift Q31 format by 15 bits to give Q16
#define Q31_TO_Q16_SHIFT_1    10  // Number of bits to shift in first step
#define Q31_TO_Q16_SHIFT_2    (Q31_TO_Q16_SHIFT_BITS - Q31_TO_Q16_SHIFT_1)
// Number of bits to shift in second step
 
typedef uint32_t fixed_t;
 
fixed_t FP_sqrt(fixed_t x);
 
fixed_t FP_log2(fixed_t x);
 
fixed_t FP_log(fixed_t x);
 
int32_t sqrt_int32(int32_t v);
 
#ifdef __cplusplus
}
#endif
 
#endif /* CH_MATH_UTILS_H_ */