math.h

一个用于智能手机的多媒体库适合S60 WinCE的跨平台开发库

/*
 *			GPAC - Multimedia Framework C SDK
 *
 *			Copyright (c) Jean Le Feuvre 2000-2005 
 *					All rights reserved
 *
 *  This file is part of GPAC / common tools sub-project
 *
 *  GPAC is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *   
 *  GPAC is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *   
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 
 *
 */

#ifndef _GF_MATH_H_
#define _GF_MATH_H_

#ifdef __cplusplus
extern "C" {
#endif

/*!
 *	\file <gpac/math.h>
 *	\brief math and trigo functions.
 */

#include <gpac/setup.h>
	
/*NOTE: there is a conflict on Win32 VC6 with C++ and gpac headers when including <math.h>*/
#if !defined(__cplusplus) || defined(__SYMBIAN32__)
#include <math.h>
#endif

/*!
 \cond DUMMY_DOXY_SECTION
*/

#ifndef GPAC_FIXED_POINT
/*note: 
		to turn fp on, change to GPAC_FIXED_POINT
		to turn fp off, change to GPAC_NO_FIXED_POINT
	this is needed by configure+sed to modify this file directly
*/
#define GPAC_NO_FIXED_POINT
#endif

/*!
 \endcond
*/


/*!
 *\addtogroup math_grp math
 *\ingroup utils_grp
 *\brief Mathematics and Trigonometric functions
 *
 *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.\n
 *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.\n
 *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
 *	@{
 */


/*****************************************************************************************
			FIXED-POINT SUPPORT - HARDCODED FOR 16.16 representation
	the software rasterizer also use a 16.16 representation even in non-fixed version
******************************************************************************************/

#ifdef GPAC_FIXED_POINT

/*!
 *Fixed 16.16 number
 *\hideinitializer
 \note This documentation has been generated for a fixed-point version of the GPAC framework.
 */
typedef s32 Fixed;
#define FIX_ONE			0x10000L
#define INT2FIX(v)		((Fixed)( ((s32) (v) ) << 16))
#define FLT2FIX(v)		((Fixed) ((v) * FIX_ONE))
#define FIX2INT(v)		((s32)(((v)+((FIX_ONE>>1)))>>16))
#define FIX2FLT(v)		((Float)( ((Float)(v)) / ((Float) FIX_ONE)))
#define FIX_EPSILON		2
#define FIX_MAX			0x7FFFFFFF
#define FIX_MIN			-FIX_MAX
#define GF_PI2		102944
#define GF_PI		205887
#define GF_2PI		411774

/*!\return 1/a, expressed as fixed number*/
Fixed gf_invfix(Fixed a);
/*!\return a*b, expressed as fixed number*/
Fixed gf_mulfix(Fixed a, Fixed b);
/*!\return a*b/c, expressed as fixed number*/
Fixed gf_muldiv(Fixed a, Fixed b, Fixed c);
/*!\return a/b, expressed as fixed number*/
Fixed gf_divfix(Fixed a, Fixed b);
/*!\return sqrt(a), expressed as fixed number*/
Fixed gf_sqrt(Fixed x);
/*!\return ceil(a), expressed as fixed number*/
Fixed gf_ceil(Fixed a);
/*!\return floor(a), expressed as fixed number*/
Fixed gf_floor(Fixed a);
/*!\return cos(a), expressed as fixed number*/
Fixed gf_cos(Fixed angle);
/*!\return sin(a), expressed as fixed number*/
Fixed gf_sin(Fixed angle);
/*!\return tan(a), expressed as fixed number*/
Fixed gf_tan(Fixed angle);
/*!\return acos(a), expressed as fixed number*/
Fixed gf_acos(Fixed angle);
/*!\return asin(a), expressed as fixed number*/
Fixed gf_asin(Fixed angle);
/*!\return atan(y, x), expressed as fixed number*/
Fixed gf_atan2(Fixed y, Fixed x);

#else


/*!Fixed is 32bit float number
 \note This documentation has been generated for a float version of the GPAC framework.
*/
typedef Float Fixed;
#define FIX_ONE			1.0f
#define INT2FIX(v)		((Float) (v))
#define FLT2FIX(v)		((Float) (v))
#define FIX2INT(v)		((s32)(v))
#define FIX2FLT(v)		((Float) (v))
#define FIX_EPSILON		GF_EPSILON_FLOAT
#define FIX_MAX			GF_MAX_FLOAT
#define FIX_MIN			-GF_MAX_FLOAT
#define GF_PI2		1.5707963267949f
#define GF_PI		3.1415926535898f
#define GF_2PI		6.2831853071796f

/*!\hideinitializer 1/_a, expressed as fixed number*/
#define gf_invfix(_a)	(FIX_ONE/(_a))
/*!\hideinitializer _a*_b, expressed as fixed number*/
#define gf_mulfix(_a, _b)		((_a)*(_b))
/*!\hideinitializer _a*_b/_c, expressed as fixed number*/
#define gf_muldiv(_a, _b, _c)	((_c) ? (_a)*(_b)/(_c) : GF_MAX_FLOAT)
/*!\hideinitializer _a/_b, expressed as fixed number*/
#define gf_divfix(_a, _b)		((_b) ? (_a)/(_b) : GF_MAX_FLOAT)
/*!\hideinitializer sqrt(_a), expressed as fixed number*/
#define gf_sqrt(_a) ((Float) sqrt(_a))
/*!\hideinitializer ceil(_a), expressed as fixed number*/
#define gf_ceil(_a) ((Float) ceil(_a))
/*!\hideinitializer floor(_a), expressed as fixed number*/
#define gf_floor(_a) ((Float) floor(_a))
/*!\hideinitializer cos(_a), expressed as fixed number*/
#define gf_cos(_a) ((Float) cos(_a))
/*!\hideinitializer sin(_a), expressed as fixed number*/
#define gf_sin(_a) ((Float) sin(_a))
/*!\hideinitializer tan(_a), expressed as fixed number*/
#define gf_tan(_a) ((Float) tan(_a))
/*!\hideinitializer atan2(_y,_x), expressed as fixed number*/
#define gf_atan2(_y, _x) ((Float) atan2(_y, _x))
/*!\hideinitializer acos(_a), expressed as fixed number*/
#define gf_acos(_a) ((Float) acos(_a))
/*!\hideinitializer asin(_a), expressed as fixed number*/
#define gf_asin(_a) ((Float) asin(_a))

#endif

/*!\def FIX_ONE
 \hideinitializer
 Fixed unit value
*/
/*!\def INT2FIX(v)
 \hideinitializer
 Conversion from integer to fixed
*/
/*!\def FLT2FIX(v)
 \hideinitializer
 Conversion from float to fixed
*/
/*!\def FIX2INT(v)
 \hideinitializer
 Conversion from fixed to integer
*/
/*!\def FIX2FLT(v)
 \hideinitializer
 Conversion from fixed to float
*/
/*!\def FIX_EPSILON
 \hideinitializer
 Epsilon Fixed (positive value closest to 0)
*/
/*!\def FIX_MAX
 \hideinitializer
 Maximum Fixed (maximum representable fixed value)
*/
/*!\def FIX_MIN
 \hideinitializer
 Minimum Fixed (minimum representable fixed value)
*/
/*!\def GF_PI2
 \hideinitializer
 PI/2 expressed as Fixed
*/
/*!\def GF_PI
 \hideinitializer
 PI expressed as Fixed
*/
/*!\def GF_2PI
 \hideinitializer
 2*PI expressed as Fixed
*/

Fixed gf_angle_diff(Fixed a, Fixed b);

/*!
 *	\brief Field bit-size 
 *
 *	Gets the number of bits needed to represent the value.
 *	\param MaxVal Maximum value to be represented.
 *	\return number of bits required to represent the value.
 */
u32 gf_get_bit_size(u32 MaxVal);

/*!
 *\addtogroup math2d_grp math2d
 *\ingroup math_grp
 *\brief 2D Mathematics functions
 *
 *This section documents mathematic tools for 2D geometry and color matrices operations
 *	@{
 */

/*!\brief 2D point
 *
 *The 2D point object is used in all the GPAC framework for both point and vector representation.
*/
typedef struct __vec2f
{
	Fixed x;
	Fixed y;
} GF_Point2D;
/*!
 *\brief get 2D vector length
 *
 *Gets the length of a 2D vector
 *\return length of the vector
 */
Fixed gf_v2d_len(GF_Point2D *vec);
/*!
 *\brief 2D vector from polar coordinates
 *
 *Constructs a 2D vector from its polar coordinates
 *\param length the length of the vector
 *\param angle the angle of the vector in radians
 *\return the 2D vector
 */
GF_Point2D gf_v2d_from_polar(Fixed length, Fixed angle);

/*!\brief rectangle 2D
 *
 *The 2D rectangle used in the GPAC project.
 */
typedef struct
{
	/*!the left coordinate of the rectangle*/
	Fixed x;
	/*!the top coordinate of the rectangle, regardless of the canvas orientation. In other words, y is always the 
	greatest coordinate value, 	even if the rectangle is presented bottom-up. This insures proper rectangles testing*/
	Fixed y;
	/*!the width of the rectangle. Width must be greater than or equal to 0*/
	Fixed width;
	/*!the height of the rectangle. Height must be greater than or equal to 0*/
	Fixed height;
} GF_Rect;

/*!
 \brief rectangle union
 *
 *Gets the union of two rectangles.
 *\param rc1 first rectangle of the union. Upon return, this rectangle will contain the result of the union
 *\param rc2 second rectangle of the union
*/
void gf_rect_union(GF_Rect *rc1, GF_Rect *rc2);
/*!
 \brief centers a rectangle
 *
 *Builds a rectangle centered on the origin
 *\param w width of the rectangle
 *\param h height of the rectangle
 *\return centered rectangle object
*/
GF_Rect gf_rect_center(Fixed w, Fixed h);
/*!
 \brief rectangle overlap test
 *
 *Tests if two rectangles overlap.
 *\param rc1 first rectangle to test
 *\param rc2 second rectangle to test
 *\return 1 if rectangles overlap, 0 otherwise
*/
Bool gf_rect_overlaps(GF_Rect rc1, GF_Rect rc2);
/*!
 \brief rectangle identity test
 *
 *Tests if two rectangles are identical.
 *\param rc1 first rectangle to test
 *\param rc2 second rectangle to test
 *\return 1 if rectangles are identical, 0 otherwise
*/
Bool gf_rect_equal(GF_Rect rc1, GF_Rect rc2);

/*!
 *\brief pixel-aligned rectangle
 *
 *Pixel-aligned rectangle used in the GPAC framework. This is usually needed for 2D drawing algorithms.
 */
typedef struct
{
	/*!the left coordinate of the rectangle*/
	s32 x;
	/*!the top coordinate of the rectangle, regardless of the canvas orientation. In other words, y is always the 
	greatest coordinate value, even if the rectangle is presented bottom-up. This insures proper rectangles operations*/
	s32 y;
	/*!the width of the rectangle. Width must be greater than or equal to 0*/
	s32 width;
	/*!the height of the rectangle. Height must be greater than or equal to 0*/
	s32 height;
} GF_IRect;
/*!
 *\brief gets the pixelized version of a rectangle