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

	Point functions

	Rect functions

	Vector functions

Variables
int	POINT::x

int	POINT::y

int	RECT::left

int	RECT::top

int	RECT::right

int	RECT::bottom

FIXED	VECTOR::x

FIXED	VECTOR::y

FIXED	VECTOR::z

Boundary response macros
INLINE FIXED	int2fx (int d)
	Convert an integer to fixed-point.

INLINE FIXED	float2fx (float f)
	Convert a float to fixed-point.

INLINE u32	fx2uint (FIXED fx)
	Convert a FIXED point value to an unsigned integer (orly?).

INLINE u32	fx2ufrac (FIXED fx)
	Get the unsigned fractional part of a fixed point value (orly?).

INLINE int	fx2int (FIXED fx)
	Convert a FIXED point value to an signed integer.

INLINE float	fx2float (FIXED fx)
	Convert a fixed point value to floating point.

INLINE FIXED	fxadd (FIXED fa, FIXED fb)
	Add two fixed point values.

INLINE FIXED	fxsub (FIXED fa, FIXED fb)
	Subtract two fixed point values.

INLINE FIXED	fxmul (FIXED fa, FIXED fb)
	Multiply two fixed point values.

INLINE FIXED	fxdiv (FIXED fa, FIXED fb)
	Divide two fixed point values.

INLINE FIXED	fxmul64 (FIXED fa, FIXED fb)
	Multiply two fixed point values using 64bit math.

INLINE FIXED	fxdiv64 (FIXED fa, FIXED fb)
	Divide two fixed point values using 64bit math.

#define	FIX_SHIFT 8
	Range check.

#define	FIX_SCALE ( 1<<FIX_SHIFT )
	Range check.

#define	FIX_MASK ( FIX_SCALE-1 )
	Range check.

#define	FIX_SCALEF ( (float)FIX_SCALE )
	Range check.

#define	FIX_SCALEF_INV ( 1.0/FIX_SCALEF )
	Range check.

#define	FIX_ONE FIX_SCALE
	Range check.

#define	FX_RECIPROCAL(a, fp) ( ((1<<(fp))+(a)-1)/(a) )
	Get the fixed point reciprocal of a, in fp fractional bits.

#define	FX_RECIMUL(x, a, fp) ( ((x)*((1<<(fp))+(a)-1)/(a))>>(fp) )
	Perform the division x/ a by reciprocal multiplication.

Detailed Description

Macro Definition Documentation

◆ FX_RECIMUL

#define FX_RECIMUL	(	x,
		a,
		fp
	)	( ((x)*((1<<(fp))+(a)-1)/(a))>>(fp) )

Perform the division x/ a by reciprocal multiplication.

Division is slow, but you can approximate division by a constant by multiplying with its reciprocal: x/a vs x*(1/a). This routine gives the reciprocal of a as a fixed point number with fp fractional bits.

Parameters

a	Value to take the reciprocal of.
fp	Number of fixed point bits

Note

The routine does do a division, but the compiler will optimize it to a single constant ... if both a and fp are constants!

Rules for safe reciprocal division, using n = 2^fp and m = (n+a-1)/a (i.e., rounding up)

Maximum safe numerator x: x < n/(m*a-n)
Minimum n for known x: n > x*(a-1)

◆ FX_RECIPROCAL

#define FX_RECIPROCAL	(	a,
		fp
	)	( ((1<<(fp))+(a)-1)/(a) )

Get the fixed point reciprocal of a, in fp fractional bits.

Parameters

a	Value to take the reciprocal of.
fp	Number of fixed point bits

Note: The routine does do a division, but the compiler will optimize it to a single constant ... if both a and fp are constants!

See also: FX_RECIMUL

Modules

Variables

Boundary response macros

Detailed Description

Macro Definition Documentation

◆ FX_RECIMUL

◆ FX_RECIPROCAL