Math

Mathematics and Trigonometric. More...

Collaboration diagram for Math:

Modules
	Math 2d
	2D Mathematics
	Math 3d
	3D Mathematics
	2D Vector Path
	Vectorial 2D Path manipulation.

Macros
#define	FIX_ONE
#define	INT2FIX(v)
#define	FLT2FIX(v)
#define	FIX2INT(v)
#define	FIX2FLT(v)
#define	FIX_EPSILON
#define	FIX_MAX
#define	FIX_MIN
#define	GF_PI2
#define	GF_PI
#define	GF_2PI
#define	gf_invfix(_a)
#define	gf_mulfix(_a, _b)
#define	gf_muldiv(_a, _b, _c)
#define	gf_divfix(_a, _b)
#define	gf_sqrt(_a)
#define	gf_ceil(_a)
#define	gf_floor(_a)
#define	gf_cos(_a)
#define	gf_sin(_a)
#define	gf_tan(_a)
#define	gf_atan2(_y, _x)
#define	gf_acos(_a)
#define	gf_asin(_a)

Typedefs
typedef Float	Fixed

Functions
Fixed	gf_angle_diff (Fixed a, Fixed b)
u32	gf_get_bit_size (u32 MaxVal)
	Field bit-size. More...
u32	gf_get_next_pow2 (u32 val)
	Get power of 2. More...

Detailed Description

This section documents the math and trigo functions used in the GPAC framework. GPAC can be compiled with fixed-point support, representing float values on a 16.16 signed integer, which implies a developer must take care of float computations when using GPAC.
A developer should not need to know in which mode the framework has been compiled as long as (s)he uses the math functions of GPAC which work in both float and fixed-point mode.
Using fixed-point version is decided at compilation time and cannot be changed. The feature is signaled through the GPAC_FIXED_POINT macro: when defined, GPAC has been compiled in fixed-point mode

Macro Definition Documentation

FIX_ONE

#define FIX_ONE

Fixed unit value

INT2FIX

#define INT2FIX

(

v

)

Conversion from integer to fixed

FLT2FIX

#define FLT2FIX

(

v

)

Conversion from float to fixed

FIX2INT

#define FIX2INT

(

v

)

Conversion from fixed to integer

FIX2FLT

#define FIX2FLT

(

v

)

Conversion from fixed to float

FIX_EPSILON

#define FIX_EPSILON

Epsilon Fixed (positive value closest to 0)

FIX_MAX

#define FIX_MAX

Maximum Fixed (maximum representable fixed value)

FIX_MIN

#define FIX_MIN

Minimum Fixed (minimum representable fixed value)

GF_PI2

#define GF_PI2

PI/2 expressed as Fixed

GF_PI

#define GF_PI

PI expressed as Fixed

GF_2PI

#define GF_2PI

2*PI expressed as Fixed

gf_invfix

#define gf_invfix

(

_a

)

1/_a, expressed as fixed number

gf_mulfix

#define gf_mulfix	(		_a,
			_b
	)

_a*_b, expressed as fixed number

gf_muldiv

#define gf_muldiv	(		_a,
			_b,
			_c
	)

_a*_b/_c, expressed as fixed number

gf_divfix

#define gf_divfix	(		_a,
			_b
	)

_a/_b, expressed as fixed number

gf_sqrt

#define gf_sqrt

(

_a

)

sqrt(_a), expressed as fixed number

gf_ceil

#define gf_ceil

(

_a

)

ceil(_a), expressed as fixed number

gf_floor

#define gf_floor

(

_a

)

floor(_a), expressed as fixed number

gf_cos

#define gf_cos

(

_a

)

cos(_a), expressed as fixed number

gf_sin

#define gf_sin

(

_a

)

sin(_a), expressed as fixed number

gf_tan

#define gf_tan

(

_a

)

tan(_a), expressed as fixed number

gf_atan2

#define gf_atan2	(		_y,
			_x
	)

atan2(_y,_x), expressed as fixed number

gf_acos

#define gf_acos

(

_a

)

acos(_a), expressed as fixed number

gf_asin

#define gf_asin

(

_a

)

asin(_a), expressed as fixed number

Typedef Documentation

Fixed

typedef Float Fixed

Fixed is 32bit float number

Note

This documentation has been generated for a float version of the GPAC framework.

Function Documentation

gf_angle_diff()

Fixed gf_angle_diff	(	Fixed	a,
		Fixed	b
	)

compute the difference between two angles, with a result in [-PI, PI]

Parameters

a	first angle
b	first angle

Returns

angle difference

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gf_get_bit_size()

u32 gf_get_bit_size

(

u32

MaxVal

)

Gets the number of bits needed to represent the value.

Parameters

MaxVal

Maximum value to be represented.

Returns

number of bits required to represent the value.

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gf_get_next_pow2()

u32 gf_get_next_pow2

(

u32

val

)

Gets the closest power of 2 greater or equal to the value.

Parameters

val	value to be used.

Returns

requested power of 2.

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