Math functions

Data Structures
struct	PA_Point
	Simple point structure. More...

Macros
#define	PA_Cos(angle)   PA_SIN[((angle) + 128)&511]
	Returns the Cos value for an angle. The value goes from -256 to 256... Watch out though : the angle is not in 360 degrees, but in 512 !
#define	PA_Sin(angle)   PA_SIN[((angle))&511]
	Returns the Sin value for an angle. The value goes from -256 to 256... Watch out though : the angle is not in 360 degrees, but in 256 !

Functions
static u32	PA_Rand ()
	Gives a random number, taken from Ham... This is taken from Ham, I have no credit.
static void	PA_InitRand ()
	Auto-seeds the Rand function based on the clock !
static void	PA_SRand (s32 r)
	Set the random's seed. This is taken from Ham, I have no credit. I just made it a little shorter/faster (maybe)
static u32	PA_RandMax (u32 max)
	Gives a random number, between 0 and the given number (included)
static u32	PA_RandMinMax (u32 min, u32 max)
	Gives a random number, between the 2 given numbers (included)
static u64	PA_Distance (s32 x1, s32 y1, s32 x2, s32 y2)
	Calculate the distance (squared) between 2 points.
static u64	PA_TrueDistance (s32 x1, s32 y1, s32 x2, s32 y2)
	Calculate the real distance between 2 points. A lot slower than PA_Distance.
u16	PA_AdjustAngle (u16 angle, s16 anglerot, s32 startx, s32 starty, s32 targetx, s32 targety)
	Adjust an angle, for example to calculate in which direction an object shoudl turn.
static u16	PA_GetAngle (s32 startx, s32 starty, s32 targetx, s32 targety)
	Get the angle, from 0 to 511, formed between the horizontal and the line.
int	PA_mulf32 (int a, int b)
	Multiplies two .12 fixed point integers.
int	PA_divf32 (int a, int b)
	Divides two .12 fixed point integers.
int	PA_modf32 (int a, int b)
	Gets the remainder of the division between two .12 fixed point integers (modulo)
int	PA_sqrtf32 (int a)
	Gets the square root of a .12 fixed point integer.

Detailed Description

Adjust angles, get random values...

Function Documentation

PA_SRand()

void PA_SRand ( s32  r )

inlinestatic

Set the random's seed. This is taken from Ham, I have no credit. I just made it a little shorter/faster (maybe)

Parameters

r	Seed value

PA_RandMax()

static inline u32 PA_RandMax ( u32  max )

inlinestatic

Gives a random number, between 0 and the given number (included)

Parameters

max	Maximum included value

PA_RandMinMax()

static inline u32 PA_RandMinMax ( u32  min, u32  max  )

inlinestatic

Gives a random number, between the 2 given numbers (included)

Parameters

min	Minimum included value
max	Maximum included value

PA_Distance()

static inline u32 PA_Distance ( s32  x1, s32  y1, s32  x2, s32  y2  )

inlinestatic

Calculate the distance (squared) between 2 points.

Parameters

x1	X coordinate of the fist point
y1	Y coordinate of the first point
x2	X coordinate of the second point
y2	Y coordinate of the second point

PA_TrueDistance()

static inline u32 PA_TrueDistance ( s32  x1, s32  y1, s32  x2, s32  y2  )

inlinestatic

Calculate the real distance between 2 points. A lot slower than PA_Distance.

Parameters

x1	X coordinate of the fist point
y1	Y coordinate of the first point
x2	X coordinate of the second point
y2	Y coordinate of the second point

PA_AdjustAngle()

u16 PA_AdjustAngle	(	u16	angle,
		s16	anglerot,
		s32	startx,
		s32	starty,
		s32	targetx,
		s32	targety
	)

Adjust an angle, for example to calculate in which direction an object shoudl turn.

Parameters

angle	Base angle, from 0 to 511
anglerot	For how much to turn...
startx	Initial X position
starty	Initial Y position
targetx	Target X position
targety	Target Y position

PA_GetAngle()

static inline u16 PA_GetAngle ( s32  startx, s32  starty, s32  targetx, s32  targety  )

inlinestatic

Get the angle, from 0 to 511, formed between the horizontal and the line.

Parameters

startx	Initial X position
starty	Initial Y position
targetx	Target X position
targety	Target Y position

PA_mulf32()

int PA_mulf32	(	int	a,
		int	b
	)

Multiplies two .12 fixed point integers.

Parameters

a	First number
b	Second number

PA_divf32()

int PA_divf32	(	int	a,
		int	b
	)

Divides two .12 fixed point integers.

Parameters

a	First number
b	Second number

PA_modf32()

int PA_modf32	(	int	a,
		int	b
	)

Gets the remainder of the division between two .12 fixed point integers (modulo)

Parameters

a	First number
b	Second number

PA_sqrtf32()

int PA_sqrtf32

(

int

a

)

Gets the square root of a .12 fixed point integer.

Parameters

a

Number