/* This file is part of the KDE project Copyright (C) 2001, The Karbon Developers Copyright (C) 2002, The Karbon Developers This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library 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 Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA 02110-1301, USA. */ #ifndef __VGLOBAL_H__ #define __VGLOBAL_H__ #include <kglobal.h> // define some often used mathematical constants et al: // TODO: optimize those values. namespace VGlobal { const double pi = 3.14159265358979323846; // pi const double twopi = 6.28318530717958647692; // 2pi const double pi_2 = 1.57079632679489661923; // pi/2 const double pi_180 = 0.01745329251994329576; // pi/180 const double one_pi_180 = 57.29577951308232087684; // 180/pi const double sqrt2 = 1.41421356237309504880; // sqrt(2) const double one_3 = 0.33333333333333333333; // 1/3 const double two_3 = 0.66666666666666666667; // 2/3 const double one_6 = 0.16666666666666666667; // 1/6 const double one_7 = 0.14285714285714285714; // 1/7 /** * Constants used to decide if a number is equal zero or nearly the same * as another number. */ const double veryBigNumber = 1.0e8; const double verySmallNumber = 1.0e-8; /** * A bezier with this flatness is considered "flat". Used in subdividing. */ const double flatnessTolerance = 0.01; /** * A tolerance used to approximate bezier lengths. If the relative difference * between chordlength and polylength (length of the controlpolygon) is smaller * than this value, the length of the bezier is 1/2 chordlength + 1/2 polylength. */ const double lengthTolerance = 0.005; /** * A tolerance used to calculate param t on a segment at a given arc * length (counting from t=0). * If the relative difference between a length approximation and the given * length is smaller than this value, they are assumed to be identical. */ const double paramLengthTolerance = 0.001; /** * A range for KoPoint::isNear() check, to decide if a KoPoint "is the same" * as another. */ const double isNearRange = 0.001; /** * A tolerance for multiplying normalized (length=1) vectors. A result of * >= parallelTolerance indicates parallel vectors. */ const double parallelTolerance = 0.99; /** * Returns the sign of paramater a. */ inline int sign( double a ) { return a < 0.0 ? -1 : 1; } /** * Calculates the binomial coefficient n! / ( k! * ( n - k)! ). */ int binomialCoeff( unsigned n, unsigned k ); /** * Calculates the value ln( n! ). */ double factorialLn( unsigned n ); /** * Calculates the value ln| Gamma(x) | for x > 0. */ double gammaLn( double x ); } #endif