File sstep_math.c

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• #include "sstep_math.h"
• #include <stdbool.h>
• #include <stddef.h>
• #include "sstep_defs.h"
• #include "sstep_sin_table.h"

Public Static Functions

Type	Name
uint32_t	bit_length (uint64_t v) Number of significant bits of v (0 for 0); binary search, 6 steps.
sstep_real_t	quarter_sin (uint32_t pos) sin(pos) for 0 <= pos < 90 deg (pos in 2^-32 turn), interpolated.
uint64_t	ratio_round (uint64_t n, uint64_t d, uint32_t s) round(n * 2^s / d); the caller guarantees n * 2^s < 2^63.

Macros

Type	Name
define	FRAC_BITS (QUADRANT\_BITS - [**SSTEP\_CFG\_SINE\_TABLE\_BITS**](group__sstep__config.md#define-sstep_cfg_sine_table_bits)) Bits of the angle below the table index (interpolation fraction).
define	QUADRANT_BITS 30U Bits of an angle inside one quadrant.
define	QUADRANT_MASK 0x3FFFFFFFU Mask of the angle inside one quadrant.
define	RATIO64_LIMIT ((int64\_t)0x4000000000000000) Operand limit of sstep_gain_from_ratio64() : 2^62.

Public Static Functions Documentation

function bit_length

Number of significant bits of v (0 for 0); binary search, 6 steps.

static uint32_t bit_length (
    uint64_t v
) 

---

function quarter_sin

sin(pos) for 0 <= pos < 90 deg (pos in 2^-32 turn), interpolated.

static sstep_real_t quarter_sin (
    uint32_t pos
) 

The index is at most N - 1, so idx + 1 is inside the table (N + 1 entries).

---

function ratio_round

round(n * 2^s / d); the caller guarantees n * 2^s < 2^63.

static uint64_t ratio_round (
    uint64_t n,
    uint64_t d,
    uint32_t s
) 

---

Macro Definition Documentation

define FRAC_BITS

Bits of the angle below the table index (interpolation fraction).

#define FRAC_BITS `(QUADRANT_BITS - SSTEP_CFG_SINE_TABLE_BITS )`

---

define QUADRANT_BITS

Bits of an angle inside one quadrant.

#define QUADRANT_BITS `30U`

---

define QUADRANT_MASK

Mask of the angle inside one quadrant.

#define QUADRANT_MASK `0x3FFFFFFFU`

---

define RATIO64_LIMIT

Operand limit of sstep_gain_from_ratio64() : 2^62.

#define RATIO64_LIMIT `((int64_t)0x4000000000000000)`

---

---

The documentation for this class was generated from the following file src/sstep_math.c