File indexing completed on 2024-05-12 16:30:46

 /* This file is part of the KDE project
    Copyright (C) 2001-2002 Lennart Kudling <kudling@kde.org>
    Copyright (C) 2002-2003 Rob Buis <buis@kde.org>
    Copyright (C) 2005 Thomas Zander <zander@kde.org>
    Copyright (C) 2006 Tim Beaulen <tbscope@gmail.com>
    Copyright (C) 2008 Jan Hambrecht <jaham@gmx.net>
 
    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 KARBONGLOBAL_H
 #define KARBONGLOBAL_H
 
 #include <karboncommon_export.h>
 
 #include <QPointF>
 
 // define some often used mathematical constants et al:
 
 // TODO: optimize those values.
 
 namespace KarbonGlobal
 {
 const qreal pi          =  3.14159265358979323846;  // pi
 const qreal twopi       =  6.28318530717958647692;  // 2pi
 const qreal pi_2        =  1.57079632679489661923;  // pi/2
 const qreal pi_180      =  0.01745329251994329576;  // pi/180
 const qreal one_pi_180  = 57.29577951308232087684;  // 180/pi
 const qreal sqrt2       =  1.41421356237309504880;  // sqrt(2)
 const qreal one_3       =  0.33333333333333333333;  // 1/3
 const qreal two_3       =  0.66666666666666666667;  // 2/3
 const qreal one_6       =  0.16666666666666666667;  // 1/6
 const qreal one_7       =  0.14285714285714285714;  // 1/7
 
 /**
 * Constants used to decide if a number is equal zero or nearly the same
 * as another number.
 */
 const qreal veryBigNumber = 1.0e8;
 const qreal verySmallNumber = 1.0e-8;
 
 /**
 * A bezier with this flatness is considered "flat". Used in subdividing.
 */
 const qreal 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 qreal 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 qreal paramLengthTolerance = 0.001;
 
 /**
 * A range for the isNear() check, to decide if a QPointF "is the same"
 * as another.
 */
 const qreal isNearRange = 0.001;
 
 /**
 * A tolerance for multiplying normalized (length=1) vectors. A result of
 * >= parallelTolerance indicates parallel vectors.
 */
 const qreal parallelTolerance = 0.99;
 
 /**
 * Returns the sign of parameter a.
 */
 inline int sign(qreal 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! ).
 */
 qreal factorialLn(unsigned n);
 
 /**
 * Calculates the value ln| Gamma(x) | for x > 0.
 */
 qreal gammaLn(qreal x);
 
 /// Returns scalar product of two given vectors
 KARBONCOMMON_EXPORT qreal scalarProduct(const QPointF &p1, const QPointF &p2);
 
 bool pointsAreNear(const QPointF &p1, const QPointF &p2, qreal range);
 
 /// Returns the cross product of two given vectors
 QPointF crossProduct(const QPointF &v1, const QPointF &v2);
 }
 
 #endif // KARBONGLOBAL_H