shithub: rgbds

ref: ddb1d0b6aa6fb36081e2cc24176c0e6e77bcbe44
dir: /src/asm/fixpoint.c/

/*
 * This file is part of RGBDS.
 *
 * Copyright (c) 1997-2021, Carsten Sorensen and RGBDS contributors.
 *
 * SPDX-License-Identifier: MIT
 */

// Fixed-point math routines

#include <inttypes.h>
#include <math.h>
#include <stdint.h>
#include <stdio.h>

#include "asm/fixpoint.h"
#include "asm/symbol.h"
#include "asm/warning.h"

#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif

#define fix2double(i)	((double)((i) / fix_PrecisionFactor()))
#define double2fix(d)	((int32_t)round((d) * fix_PrecisionFactor()))

// 2*pi radians == 1 turn
#define turn2rad(f)	((f) * (M_PI * 2))
#define rad2turn(r)	((r) / (M_PI * 2))

uint8_t fixPrecision;

double fix_PrecisionFactor(void)
{
	return pow(2.0, fixPrecision);
}

void fix_Print(int32_t i)
{
	uint32_t u = i;
	char const *sign = "";

	if (i < 0) {
		u = -u;
		sign = "-";
	}

	printf("%s%" PRIu32 ".%05" PRIu32, sign, u >> fixPrecision,
	       ((uint32_t)(fix2double(u) * 100000 + 0.5)) % 100000);
}

int32_t fix_Sin(int32_t i)
{
	return double2fix(sin(turn2rad(fix2double(i))));
}

int32_t fix_Cos(int32_t i)
{
	return double2fix(cos(turn2rad(fix2double(i))));
}

int32_t fix_Tan(int32_t i)
{
	return double2fix(tan(turn2rad(fix2double(i))));
}

int32_t fix_ASin(int32_t i)
{
	return double2fix(rad2turn(asin(fix2double(i))));
}

int32_t fix_ACos(int32_t i)
{
	return double2fix(rad2turn(acos(fix2double(i))));
}

int32_t fix_ATan(int32_t i)
{
	return double2fix(rad2turn(atan(fix2double(i))));
}

int32_t fix_ATan2(int32_t i, int32_t j)
{
	return double2fix(rad2turn(atan2(fix2double(i), fix2double(j))));
}

int32_t fix_Mul(int32_t i, int32_t j)
{
	return double2fix(fix2double(i) * fix2double(j));
}

int32_t fix_Div(int32_t i, int32_t j)
{
	return double2fix(fix2double(i) / fix2double(j));
}

int32_t fix_Mod(int32_t i, int32_t j)
{
	return double2fix(fmod(fix2double(i), fix2double(j)));
}

int32_t fix_Pow(int32_t i, int32_t j)
{
	return double2fix(pow(fix2double(i), fix2double(j)));
}

int32_t fix_Log(int32_t i, int32_t j)
{
	return double2fix(log(fix2double(i)) / log(fix2double(j)));
}

int32_t fix_Round(int32_t i)
{
	return double2fix(round(fix2double(i)));
}

int32_t fix_Ceil(int32_t i)
{
	return double2fix(ceil(fix2double(i)));
}

int32_t fix_Floor(int32_t i)
{
	return double2fix(floor(fix2double(i)));
}