pokeplatinum/include/math_util.h

#ifndef POKEPLATINUM_MATH_UTIL_H
#define POKEPLATINUM_MATH_UTIL_H

#include <nitro/fx/fx.h>

#include "constants/heap.h"

#define LCRNG_MULTIPLIER 1103515245L
#define LCRNG_INCREMENT  24691
#define LCRNG_DIVISOR    65536L

// Does almost the same as FX_DEG_TO_IDX but takes integers as input instead of fx32
// Use if FX_DEG_TO_IDX(FX32_CONST(degrees)) doesn't match
#define DEG_TO_IDX(degrees) (((degrees) * 0xFFFF) / 360)

enum AffineTransformationMatrixMode {
    AFFINE_MODE_NORMAL = 0,
    AFFINE_MODE_MAX_256,
    AFFINE_MODE_MAX_360,
};

typedef struct Vec2F32 {
    f32 x;
    f32 y;
} Vec2F32;

typedef struct Point2D {
    s16 x;
    s16 y;
} Point2D;

fx32 CalcSineDegrees(u16 degrees);
fx32 CalcCosineDegrees(u16 degrees);
fx32 CalcSineDegrees_Wraparound(u16 degrees);
fx32 CalcCosineDegrees_Wraparound(u16 degrees);
u16 CalcAngleRotationIdx(u16 degrees);
u16 CalcAngleRotationIdx_Wraparound(u16 degrees);
fx32 CalcSineDegrees_FX32(fx32 degrees);
fx32 CalcCosineDegrees_FX32(fx32 degrees);

u32 LCRNG_GetSeed(void);
void LCRNG_SetSeed(u32 seed);
u16 LCRNG_Next(void);
u32 ARNG_Next(u32 seed);
void MTRNG_SetSeed(u32 seed);
u32 MTRNG_Next(void);

void CreateAffineTransformationMatrix(MtxFx22 *matrix, u16 degrees, fx32 xScale, fx32 yScale, u8 mode);

/*
 * Computes an approximation of the (signed) arc length spanned by the (signed)
 * angle from (x0, y0) to (x1, y1) on a circle of radius length((x0, y0)). The
 * last argument was most likely intended to be the radius, but went unused in
 * the final version.
 */
s32 ApproximateArcLength(s32 x0, s32 y0, s32 x1, s32 y1, u32 unused_radius);
s32 CalcRadialAngle(u16 radius, s32 distance);

u32 SumBytes(const void *data, u32 size);
void EncodeData(void *data, u32 size, u32 seed);
void DecodeData(void *data, u32 size, u32 seed);
u16 CalcCRC16Checksum(const void *data, u32 dataLen);
void InitCRC16Table(enum HeapID heapID);

#endif // POKEPLATINUM_MATH_UTIL_H