Useful math functions. More...

#include "gctypes.h"

Data Structures
struct	Point
	Struct containing the coordinates of a point. More...

Macros
#define	M_PI 3.14159265358f

#define	M_2PI 6.28318530718f

#define	M_PI_OVER_2 1.57079632679f

#define	M_PI_OVER_3 1.047197551f

#define	M_PI_OVER_4 0.785398163f

#define	M_PI_OVER_6 0.523598776f

#define	DEG_TO_RAD(x) ((x) * 0.01745329251f)

#define	RAD_TO_DEG(x) ((x) * 57.2957795131f)

#define	SIGN(x) ((x) < 0 ? -1 : 1)

Functions
float	exp (float x)
	`e` to the power `x` More...

float	log (float x)
	natural log More...

float	fabs (float x)
	Absolute value of `x`. More...

float	recipSqrt (float x)
	`1 / sqrt(x)` More...

float	floor (float x)
	Round down value. More...

float	ceil (float x)
	Round up value. More...

s32	imax (s32 a, s32 b)
	Maximum of two integers. More...

s32	imin (s32 a, s32 b)
	Minimum of two integers. More...

float	fmax (float a, float b)
	Maximum of two floating-point values. More...

float	fmin (float a, float b)
	Minimum of two floating-point values. More...

int	imod (int a, int b)
	Mod operator for integers. More...

float	fmod (float a, float b)
	Mod operator for floats. More...

s32	ipow (s16 base, u8 exp)
	`base` raised to the power of `exp` More...

float	fpow (float base, u8 exp)
	`base` raised to the power of `exp` More...

float	sqrt (float x)
	Square root of `x`. More...

float	sin (float x)
	Sine of `x`, expressed in degrees. More...

float	cos (float x)
	Cosine of `x`, expressed in degrees. More...

float	tan (float x)
	Tangent of `x`, expressed in degrees. More...

float	asin (float x)
	Arc sine of `x`. More...

float	acos (float x)
	Arc cosine of `x`. More...

float	atan (float x)
	Arc tangent of `x`. More...

float	atan2 (float y, float x)
	Compute arc tangent with two parameters. More...

float	magnitude (Point pt)
	Magnitude of point. More...

float	distance (Point a, Point b)
	Distance between two points. More...

float	angle (Point a, Point b)
	Angle between two points. More...

Detailed Description

Useful math functions.

Data Structure Documentation

struct Point

Struct containing the coordinates of a point.

Data Fields
float	x	X-coordinate of point
float	y	Y-coordinate of point

Macro Definition Documentation

#define M_PI 3.14159265358f

approximate value of pi

#define M_2PI 6.28318530718f

approximate value of 2 * pi

#define M_PI_OVER_2 1.57079632679f

approximate value of pi / 2

#define M_PI_OVER_3 1.047197551f

approximate value of pi / 3

#define M_PI_OVER_4 0.785398163f

approximate value of pi / 4

#define M_PI_OVER_6 0.523598776f

approximate value of pi / 6

#define DEG_TO_RAD ( x ) ((x) * 0.01745329251f)

degree to radian conversion

#define RAD_TO_DEG ( x ) ((x) * 57.2957795131f)

radian to degree conversion

#define SIGN ( x ) ((x) < 0 ? -1 : 1)

sign of value

Function Documentation

float exp ( float x )

e to the power x

Parameters

x	- floating-point value

Returns: e raised the power x

float log ( float x )

natural log

Parameters

x	- floating-point value, must be positive

Returns: the natural log of x

float fabs ( float x )

Absolute value of x.

Parameters

x	- floating-point value

Returns: The absolute value of x.

float recipSqrt ( float x )

1 / sqrt(x)

Parameters

x	- floating-point value

Returns: the reciprical square root of x

float floor ( float x )

Round down value.

Rounds x downward, returning the largest integral value that is not greater than @ x

Parameters

x	- floating-point value

Returns: The value of x rounded downward (as a floating-point value)

See also: http://www.cplusplus.com/reference/cmath/floor/

float ceil ( float x )

Round up value.

Rounds x upward, returning the smallest integral value that is not less than @ x

Parameters

x	- floating-point value

Returns: The value of x rounded upward (as a floating-point value)

See also: http://www.cplusplus.com/reference/cmath/floor/

s32 imax	(	s32	a,
		s32	b
	)

Maximum of two integers.

Parameters

a	- 32-bit `signed` `int`
b	- 32-bit `signed` `int`

Returns: The larger value of a and b

s32 imin	(	s32	a,
		s32	b
	)

Minimum of two integers.

Parameters

a	- 32-bit `signed` `int`
b	- 32-bit `signed` `int`

Returns: The smaller value of a and b

float fmax	(	float	a,
		float	b
	)

Maximum of two floating-point values.

Parameters

a	- floating-point value
b	- floating-point value

Returns: The larger value of a and b

float fmin	(	float	a,
		float	b
	)

Minimum of two floating-point values.

Parameters

a	- floating-point value
b	- floating-point value

Returns: The smaller value of a and b

int imod	(	int	a,
		int	b
	)

Mod operator for integers.

Parameters

a	- `signed` `int`
b	- `signed` `int`

Returns: a mod b

float fmod	(	float	a,
		float	b
	)

Mod operator for floats.

Parameters

a	- floating-point value
b	- floating-point value

Returns: a mod b

s32 ipow	(	s16	base,
		u8	exp
	)

base raised to the power of exp

Parameters

base	- 16-bit `signed` `int`
exp	- 8-bit `signed` `int`

Returns: base raised to the power of exp

float fpow	(	float	base,
		u8	exp
	)

base raised to the power of exp

Parameters

base	- floating-point value
exp	- 8-bit `signed` `int`

Returns: base raised to the power of exp

float sqrt ( float x )

Square root of x.

Parameters

x	- floating-point value

Returns: the square root of x

float sin ( float x )

Sine of x, expressed in degrees.

Parameters

x	- floating-point value in `[0, 360)`

Returns: Sine of x

float cos ( float x )

Cosine of x, expressed in degrees.

Parameters

x	- floating-point value in `[0, 360)`

Returns: Cosine of x

float tan ( float x )

Tangent of x, expressed in degrees.

Parameters

x	- floating-point value in `[0, 360)`

Returns: Tangent of x

float asin ( float x )

Arc sine of x.

Parameters

x	- floating-point value in `[-1, +1]`

Returns: inverse sine of x, expressed in degress in range [0, 90] and [270, 360)

float acos ( float x )

Arc cosine of x.

Parameters

x	- floating-point value in `[-1, +1]`

Returns: inverse cosine of x, expressed in degress in range [0, 180]

float atan ( float x )

Arc tangent of x.

Parameters

x	- floating-point value in `[0, inf)`

Returns: inverse tangent of x, expressed in degress in range [0, 90)

float atan2	(	float	y,
		float	x
	)

Compute arc tangent with two parameters.

Returns the arc tangent of y / x, expressed in degrees. To compute the value, the function takes into accout the sign of both arguments in order to determine the quadrant.

Parameters

y	- floating-point value
x	- floating-point value

Returns: arc tangent of y / x, in interval [0, 360) degrees

See also: http://www.cplusplus.com/reference/cmath/atan2/; http://www.embedded.com/design/other/4216719/Performing-efficient-arctangent-approximation

float magnitude ( Point pt )

Magnitude of point.

Parameters

pt	- Point struct

Returns: The distance of pt from (0,0)

Note: error is within 0.26 degrees

float distance	(	Point	a,
		Point	b
	)

Distance between two points.

Parameters

a	- Point struct
b	- Point struct

Returns: The distance between a and b

float angle	(	Point	a,
		Point	b
	)

Angle between two points.

Parameters

a	- Point struct
b	- Point struct

Returns: The angle between a and b in [0, 360] degrees

Data Structures

Macros

Functions

Detailed Description

Data Structure Documentation

Macro Definition Documentation

Function Documentation