/*
* This file is part of the DXX-Rebirth project <https://www.dxx-rebirth.com/>.
* It is copyright by its individual contributors, as recorded in the
* project's Git history. See COPYING.txt at the top level for license
* terms and a link to the Git history.
*/
/* Maths.h library header file */
#pragma once
#include <cstdint>
#include <stdlib.h>
#include "pstypes.h"
#define D_RAND_MAX 32767
#ifdef __cplusplus
#include <cstddef>
#include "dxxsconf.h"
#include "dsx-ns.h"
#include <array>
namespace dcx {
void d_srand (unsigned int seed);
__attribute_warn_unused_result
int d_rand (); // Random number function which returns in the range 0-0x7FFF
//=============================== FIXED POINT ===============================
typedef int64_t fix64; //64 bits int, for timers
typedef int32_t fix; //16 bits int, 16 bits frac
typedef int16_t fixang; //angles
typedef struct quadint // integer 64 bit, previously called "quad"
{
union {
struct {
uint32_t low;
int32_t high;
};
int64_t q;
};
}
quadint;
//Convert an int to a fix/fix64 and back
static constexpr fix i2f(const int &i)
{
return i << 16;
}
static constexpr int f2i(const fix &f)
{
return f >> 16;
}
//Convert fix to float and float to fix
static constexpr float f2fl(const fix &f)
{
return static_cast<float>(f) / static_cast<float>(65536.0);
}
static constexpr double f2db(const fix &f)
{
return static_cast<double>(f) / 65536.0;
}
static constexpr fix fl2f(const float &f)
{
return static_cast<fix>(f * 65536);
}
//Some handy constants
#define f0_0 0
#define f1_0 0x10000
#define f2_0 0x20000
#define f3_0 0x30000
#define f10_0 0xa0000
#define f0_5 0x8000
#define f0_1 0x199a
//Get the int part of a fix, with rounding
static constexpr int f2ir(const fix &f)
{
return (f + f0_5) >> 16;
}
#define F0_0 f0_0
#define F1_0 f1_0
#define F2_0 f2_0
#define F3_0 f3_0
#define F10_0 f10_0
#define F0_5 f0_5
#define F0_1 f0_1
//multiply two fixes, return a fix(64)
__attribute_warn_unused_result
fix64 fixmul64 (fix a, fix b);
/* On x86/amd64 for Windows/Linux, truncating fix64->fix is free. */
__attribute_warn_unused_result
static inline fix fixmul(fix a, fix b)
{
return static_cast<fix>(fixmul64(a, b));
}
//divide two fixes, return a fix
__attribute_warn_unused_result
fix fixdiv (fix a, fix b);
//multiply two fixes, then divide by a third, return a fix
__attribute_warn_unused_result
fix fixmuldiv (fix a, fix b, fix c);
//multiply two fixes, and add 64-bit product to a quadint
static inline void fixmulaccum (quadint * q, const fix &a, const fix &b)
{
q->q += static_cast<int64_t>(a) * static_cast<int64_t>(b);
}
//extract a fix from a quadint product
__attribute_warn_unused_result
static inline fix fixquadadjust (const quadint *q)
{
return static_cast<fix>(q->q >> 16);
}
//negate a quadint
static inline void fixquadnegate (quadint * q)
{
q->q = -q->q;
}
//computes the square root of a long, returning a short
__attribute_warn_unused_result
ushort long_sqrt (int32_t a);
//computes the square root of a quadint, returning a long
__attribute_warn_unused_result
uint32_t quad_sqrt (quadint);
//computes the square root of a fix, returning a fix
__attribute_warn_unused_result
fix fix_sqrt (fix a);
struct fix_sincos_result
{
fix sin, cos;
};
__attribute_warn_unused_result
fix_sincos_result fix_sincos(fix);
//compute sine and cosine of an angle, filling in the variables
//either of the pointers can be NULL
__attribute_warn_unused_result
fix fix_sin(fix a);
__attribute_warn_unused_result
fix fix_cos(fix a);
__attribute_warn_unused_result
fix fix_fastsin(fix a); //no interpolation
//compute inverse sine & cosine
__attribute_warn_unused_result
fixang fix_asin (fix v);
__attribute_warn_unused_result
fixang fix_acos (fix v);
//given cos & sin of an angle, return that angle.
//parms need not be normalized, that is, the ratio of the parms cos/sin must
//equal the ratio of the actual cos & sin for the result angle, but the parms
//need not be the actual cos & sin.
//NOTE: this is different from the standard C atan2, since it is left-handed.
__attribute_warn_unused_result
fixang fix_atan2 (fix cos, fix sin);
__attribute_warn_unused_result
int checkmuldiv(fix *r,fix a,fix b,fix c);
extern const std::array<ubyte, 256> guess_table;
extern const std::array<int16_t, 256> sincos_table;
extern const std::array<ushort, 258> asin_table;
extern const std::array<ushort, 258> acos_table;
static inline void clamp_fix_lh(fix& f, const fix& low, const fix& high)
{
if (f < low)
f = low;
else if (high < f)
f = high;
}
static inline void clamp_fix_symmetric(fix& f, const fix& bound)
{
clamp_fix_lh(f, -bound, bound);
}
}
#endif