math

Mathematics and Trigonometric functions. More...

Collaboration diagram for math:

Modules
	math2d
	2D Mathematics functions
	math3d
	3D Mathematics functions

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 developper should not need to know in which mode the framework has been compiled as long as 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 following macros:

• GPAC_FIXED_POINT: when defined, GPAC has been compiled in fixed-point mode
• GPAC_NO_FIXED_POINT: when defined, GPAC has been compiled in regular (float) mode

Macro Definition Documentation

#define FIX_ONE

Fixed unit value

#define INT2FIX

(

v

)

Conversion from integer to fixed

#define FLT2FIX

(

v

)

Conversion from float to fixed

#define FIX2INT

(

v

)

Conversion from fixed to integer

#define FIX2FLT

(

v

)

Conversion from fixed to float

#define FIX_EPSILON

Epsilon Fixed (positive value closest to 0)

#define FIX_MAX

Maximum Fixed (maximum representable fixed value)

#define FIX_MIN

Minimum Fixed (minimum representable fixed value)

#define GF_PI2

PI/2 expressed as Fixed

#define GF_PI

PI expressed as Fixed

#define GF_2PI

2*PI expressed as Fixed

#define gf_invfix

(

_a

)

1/_a, expressed as fixed number

#define gf_mulfix	(		_a,
			_b
	)

_a*_b, expressed as fixed number

#define gf_muldiv	(		_a,
			_b,
			_c
	)

_a*_b/_c, expressed as fixed number

#define gf_divfix	(		_a,
			_b
	)

_a/_b, expressed as fixed number

#define gf_sqrt

(

_a

)

sqrt(_a), expressed as fixed number

#define gf_ceil

(

_a

)

ceil(_a), expressed as fixed number

#define gf_floor

(

_a

)

floor(_a), expressed as fixed number

#define gf_cos

(

_a

)

cos(_a), expressed as fixed number

#define gf_sin

(

_a

)

sin(_a), expressed as fixed number

#define gf_tan

(

_a

)

tan(_a), expressed as fixed number

#define gf_atan2	(		_y,
			_x
	)

atan2(_y,_x), expressed as fixed number

#define gf_acos

(

_a

)

acos(_a), expressed as fixed number

#define gf_asin

(

_a

)

asin(_a), expressed as fixed number

Typedef Documentation

typedef Float Fixed

Fixed is 32bit float number

Note

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

Function Documentation

Fixed gf_angle_diff	(	Fixed	a,
		Fixed	b
	)

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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.

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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