OAG Library (OpenGL) Part 1 - Setting Up the Library for an MFC Application

/************************************************************/
// MathDefinitions.h
// Coment: Defini��es e utilitarios
//
/************************************************************/

#pragma once

/*********** [ Constants ] *************/
/*********** [ Epsilon constants ] *************/
#define _EPSIOLON_H			(1.0E-16)
#define _EPSIOLON_M			(1.0E-12)
#define _EPSIOLON_L			(1.0E-08)
#define _EPSLN				_EPSIOLON_M

/*********** [ Fuzzy equality and zero tests for real numbers	] *************/
#define _FUZZ_REAL			(1e-15)						/*** [ Approximate floating point accuracy		] ***/
#define _FUZZ_GEN			(1e-9)						/*** [ General fuzz - nine decimal digits		] ***/
#define _FUZZ_DEG			(3e-4)						/*** [ Approximately one arc second, as degrees	] ***/
#define _FUZZ_RAD			(5e-6)						/*** [ Approximately one arc second, as radians	] ***/
#define _FUZZ_DIST			(1e-6)						/*** [ Geometric coincidence toelrance			] ***/

/*********** [ Angular constants								] *************/
#define _PIOVER2 			(1.5707963267948966192313216916398)
#define _PI					(3.141592653589793238462643383279500)
#define _3PIOVER2			(4.7123889803846898576939650749193)
#define _2PI				(6.283185307179586476925286766559000)
#define _PI_OVER_180 		(0.017453292519943295769236907684886)

#define _MAX_RADIANS			2PI
#define _MAX_DEGREES			(360.0)
#define _MAX_GRADIANS		(400.0)
#define _MAX_THOUSAND		(6400.0)

/*********** [ Angular conversions ] *************/
#define _DEG2RAD			(1.7453292519943295769236907684886e-2)
#define _RAD2DEG			(57.295779513082320876798154814105)
#define _ONE_SEC_RAD		(4.8481368110953599358991410235795e-6)
#define _ONE_MIN_RAD		(2.9088820866572159615394846141477e-4)

/*********** [ Distance conversions ] *************/
#define _METER2FEET			(3.2808398950131233595800524934383)
#define _FEET2METER			(0.3048)
#define _MILE2FEET			(5280.0)
#define _FEET2MILE			(1.8939393939393939393939393939394e-4)
#define _METERS2MILE		(0.0006213688756330195420511386584646)
#define _MILE2METER			(1609.35)
#define	_NAUTMILE2FEET		(6076.1154855643044619422572178472)
#define	_FEET2NAUTMILE		(1.6457883369330453563714902807777e-4)

/*********** [ Speed conversions ] *************/
#define	_METER_SEC2MPH		(2.2369279522788703513840991704726)
#define _METER_SEC2KMPH		(3.6)
#define	_METER_SEC2KNOTS		(1.942524361582627087283952850778)
#define	_FEET_SEC2METER_SEC	(0.3048)
#define	_FEET_SEC2KNOTS		(0.59208797017731120493004422500974)
#define	_FEET_SEC2MPH		(0.68181818181818181818181818181818)

/*********** [ Macros ] *************/
#define SQUARE(x)		x * x						/*** [ x**2										] ***/
#define CUBE(x)			x * x * x					/*** [ x**3										] ***/
#define QUAD(x)			x * x * x * x				/*** [ x**4										] ***/

#define GMAX(A, B)			((A) > (B) ? (A) : (B))		/*** [ Assign maximum of a and b				] ***/
#define GMIN(A, B)			((A) < (B) ? (A) : (B))		/*** [ Assign minimum of a and b				] ***/
#define IMOD(A, B)			(A) - (((A) / (B)) * (B))	/*** [ Integer mod function						] ***/

#define EQ(a,b)				(fabs(a-b)<1.666E-15)

#define ABS(x)				((x) < 0.0 ? -(x) : (x))
#define SWAP(x,y,type)\
{\
	type z	= x;\
	x		= y;\
	y		= z;\
}

#define DATA_EXCHANGE_NUMBER_UNITS 2
#define DEG2RAD(a)	(_PI_OVER_180*(a))
#define RAD2DEG(a)	(_RAD2DEG*(a))

/*********** [ GDI+	] *************/
#define RECTFTOP(rec)			(rec.Y+rec.Height)

/*********** [ Inline definitions ] *************/
inline int Double2Integer(double dValue)				/*** [ Double => int  (faster than a (cast))	] ***/
{													
   static double dScale		= 6755399441055744.0;
   static double dDouble	= 0.0;
   static int *pnInteger	= (int*) &dDouble;
   dDouble					= dValue + dScale;
   
   return *pnInteger;
}