pokefirered/src/math_util.c

#include "global.h"
#include "math_util.h"

s16 Q_8_8_mul(s16 x, s16 y)
{
    s32 result;

    result = x;
    result *= y;
    result /= 256;
    return result;
}

s16 Q_N_S_mul(u8 s, s16 x, s16 y)
{
    s32 result;

    result = x;
    result *= y;
    result /= (1 << s);
    return result;
}

s32 Q_24_8_mul(s32 x, s32 y)
{
    s64 result;

    result = x;
    result *= y;
    result /= 256;
    return result;
}

s16 Q_8_8_div(s16 x, s16 y)
{
    if (y == 0)
    {
        return 0;
    }
    return (x << 8) / y;
}

s16 Q_N_S_div(u8 s, s16 x, s16 y)
{
    if (y == 0)
    {
        return 0;
    }
    return (x << s) / y;
}

s32 Q_24_8_div(s32 x, s32 y)
{
    s64 _x;

    if (y == 0)
    {
        return 0;
    }
    _x = x;
    _x *= 256;
    return _x / y;
}

s16 Q_8_8_inv(s16 y)
{
    s32 x;

    x = 0x10000;
    return x / y;
}

s16 Q_N_S_inv(u8 s, s16 y)
{
    s32 x;

    x = 0x100 << s;
    return x / y;
}

s32 Q_24_8_inv(s32 y)
{
    s64 x;

    x = 0x10000;
    return x / y;
}

s16 MathUtil_Mul16(s16 x, s16 y)
{
    s32 result;

    result = x;
    result *= y;
    result /= 256;
    return result;
}

s16 MathUtil_Mul16Shift(u8 s, s16 x, s16 y)
{
    s32 result;

    result = x;
    result *= y;
    result /= (1 << s);
    return result;
}

s32 MathUtil_Mul32(s32 x, s32 y)
{
    s64 result;

    result = x;
    result *= y;
    result /= 256;
    return result;
}

s16 MathUtil_Div16(s16 x, s16 y)
{
    if (y == 0)
    {
        return 0;
    }
    return (x << 8) / y;
}

s16 MathUtil_Div16Shift(u8 s, s16 x, s16 y)
{
    if (y == 0)
    {
        return 0;
    }
    return (x << s) / y;
}

s32 MathUtil_Div32(s32 x, s32 y)
{
    s64 _x;

    if (y == 0)
    {
        return 0;
    }
    _x = x;
    _x *= 256;
    return _x / y;
}

s16 MathUtil_Inv16(s16 y)
{
    s32 x;

    x = 0x10000;
    return x / y;
}

s16 MathUtil_Inv16Shift(u8 s, s16 y)
{
    s32 x;

    x = 0x100 << s;
    return x / y;
}

s32 MathUtil_Inv32(s32 y)
{
    s64 x;

    x = 0x10000;
    return x / y;
}

u32 MathUtil_Exponent(u32 x, u32 y)
{
    u32 result = 1;
    for (u32 index = 0; index < y; index++)
        result *= x;

    return result;
}