Look-up tables
[Math]

Tonc's internal look-up tables and related routines. More...

Defines
#define	SIN_LUT_SIZE   514
#define	DIV_LUT_SIZE   257
Functions
INLINE s32	lu_sin (uint theta)
	Look-up a sine value (2π = 0x10000).
INLINE s32	lu_cos (uint theta)
	Look-up a cosine value (2π = 0x10000).
INLINE uint	lu_div (uint x)
	Look-up a division value between 0 and 255.
INLINE int	lu_lerp32 (const s32 lut[], uint x, const uint shift)
	Linear interpolator for 32bit LUTs.
INLINE int	lu_lerp16 (const s16 lut[], uint x, const uint shift)
	As lu_lerp32, but for 16bit LUTs.
Variables
s32	div_lut [257]
s16	sin_lut [514]

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Detailed Description

Tonc's internal look-up tables and related routines.

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Define Documentation

#define SIN_LUT_SIZE   514

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Function Documentation

INLINE s32 lu_cos

(

uint

theta

)

Look-up a cosine value (2π = 0x10000).

Parameters:

theta

Angle in [0,FFFFh] range

Returns:

.12f cosine value

INLINE uint lu_div

(

uint

x

)

Look-up a division value between 0 and 255.

Parameters:

x

reciprocal to look up.

Returns:

1/x (.16f)

INLINE int lu_lerp32	(	const s32	lut[],
		uint	x,
		const uint	shift
	)

Linear interpolator for 32bit LUTs.

A lut is essentially the discrete form of a function, f(x). You can get values for non-integer x via (linear) interpolation between f(x) and f(x+1).

Parameters:

	lut	The LUT to interpolate from.
	x	Fixed point number to interpolate at.
	shift	Number of fixed-point bits of x.

INLINE s32 lu_sin

(

uint

theta

)

Look-up a sine value (2π = 0x10000).

Parameters:

theta

Angle in [0,FFFFh] range

Returns:

.12f sine value

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