40 lines
993 B
C++
40 lines
993 B
C++
/*!
|
|
* \file
|
|
*
|
|
* This file contains function prototypes for very fast lookup-table based
|
|
* trigonometric functions.
|
|
*
|
|
* The functions take an argument that is dependent on the lookup-table size
|
|
* (LUT_SIZE). LUT_SIZE corresponds to 2π. Values outside the range
|
|
* [0..LUT_SIZE] are supported and interpreted normally, so just replace 2π
|
|
* with LUT_SIZE and you're done.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <cstdint>
|
|
|
|
#define FASTTRIGON_8BIT(x) ((x) >> (fasttrigon::PRECISION_BITS - 8))
|
|
|
|
namespace fasttrigon {
|
|
static const uint32_t LUT_SIZE = 2048;
|
|
static const uint32_t PRECISION_BITS = 11;
|
|
static const int32_t SCALE = 1023;
|
|
static const uint32_t UNIT_SHIFT = PRECISION_BITS-1;
|
|
|
|
/*!
|
|
* \returns 127 * sin(2π * arg / LUT_SIZE)
|
|
*/
|
|
int32_t fastsin(int32_t arg);
|
|
|
|
/*!
|
|
* \returns 127 * cos(2π * arg / LUT_SIZE)
|
|
*/
|
|
int32_t fastcos(int32_t arg);
|
|
|
|
/*!
|
|
* \returns 127 * tan(2π * arg / LUT_SIZE)
|
|
*/
|
|
int32_t fasttan(int32_t arg);
|
|
}
|