inline funcs instead of macros for fixed-point

This commit is contained in:
2024-10-15 19:41:29 +01:00
parent 3e379acd5e
commit 27d564ab49

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@@ -1,31 +1,95 @@
#include <stdint.h>
#ifndef FIXED_POINT_H
#define FIXED_POINT_H
typedef struct
{
int32_t raw;
} fp32_t;
/* Fixed Point Arithmetic bit count constants */
#define NUM_INT_BITS 11
#define NUM_FRAC_BITS 20
#define NUM_INT_BITS (31 - NUM_FRAC_BITS)
#define CONVERSION_CONST (1 << NUM_FRAC_BITS) /* f = 2^q, (2^20) */
/* Fixed Point Arithmetic conversion operations */
/* Converts an integer n to a fixed point number */
#define INT_TO_FP(n) ((n) * (CONVERSION_CONST))
inline fp32_t
int_to_fp (int32_t n)
{
return { n * CONVERSION_CONST };
}
/* Handles conversion of fixed point to integer. First version truncates, second one rounds */
#define FLOOR_FP_TO_INT(x) ((x) / (CONVERSION_CONST))
#define ROUNDING_FP_TO_INT(x) ((x) >= 0 ? ((x) + ((CONVERSION_CONST) / 2)) : ((x) - ((CONVERSION_CONST) / 2)))
inline int32_t
fp_floor (fp32_t x)
{
return { x.raw / CONVERSION_CONST };
}
/* Fixed Point Arithmetic addition operations */
#define FP_ADD(x, y) ((x) + (y))
#define FP_SUBTRACT(x, y) ((x) - (y))
/* Addition and Subtraction but between a fixed point and an integer */
#define FP_ADD_INT(x, n) ((x) + ((n) * (CONVERSION_CONST)))
#define FP_SUBTRACT_INT(x, n) ((x) - ((n) * (CONVERSION_CONST)))
inline int32_t
fp_round (fp32_t x)
{
if (x.raw >= 0)
return (x.raw + CONVERSION_CONST / 2) / CONVERSION_CONST;
else
return (x.raw - CONVERSION_CONST / 2) / CONVERSION_CONST;
}
/* Fixed Point Arithmetic multiplication operations */
#define FP_MULTIPLY(x, y) ((int64_t)(x)) * (y) / (CONVERSION_CONST)
#define FP_DIVIDE(x, y) ((int64_t)(x)) * (CONVERSION_CONST) / (y)
/* Multiplication and division but between a fixed point and an integer */
#define FP_MULTIPLY_INT(x, n) ((x) * (n))
#define FP_DIVIDE_INT(x, n) ((x) / (n))
/* Add two fixed points */
inline fp32_t
fp_add (fp32_t x, fp32_t y)
{
return { x.raw + y.raw };
}
/* Subtract two fixed points */
inline fp32_t
fp_sub (fp32_t x, fp32_t y)
{
return { x.raw - y.raw };
}
/* Add fixed point to integer */
inline fp32_t
fp_add_int (fp32_t x, int32_t n)
{
return { x.raw + n * CONVERSION_CONST };
}
/* Subtract integer from fixed point */
inline fp32_t
fp_sub_int (fp32_t x, int32_t n)
{
return { x.raw - n * CONVERSION_CONST };
}
/* Multiple two fixed points */
inline fp32_t
fp_mul (fp32_t x, fp32_t y)
{
return { ((int64_t)x.raw) * y.raw / CONVERSION_CONST };
}
/* Divide two fixed points */
inline fp32_t
fp_div (fp32_t x, fp32_t y)
{
return { ((int64_t)x.raw) * CONVERSION_CONST / y.raw };
}
/* Multiply fixed point and integer */
inline fp32_t
fp_mul_int (fp32_t x, int32_t n)
{
return { x.raw * n };
}
/* Divide fixed point by integer */
inline fp32_t
fp_div_int (fp32_t x, int32_t n)
{
return { x.raw / n };
}
#endif //FIXED_POINT_H