kig/objects/curve_imp.h

   1 // Copyright (C)  2002  Dominique Devriese <devriese@kde.org>
   2
   3 // This program is free software; you can redistribute it and/or
   4 // modify it under the terms of the GNU General Public License
   5 // as published by the Free Software Foundation; either version 2
   6 // of the License, or (at your option) any later version.
   7
   8 // This program is distributed in the hope that it will be useful,
   9 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 // GNU General Public License for more details.
  12
  13 // You should have received a copy of the GNU General Public License
  14 // along with this program; if not, write to the Free Software
  15 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  16 // 02111-1307, USA.
  17
  18 #ifndef KIG_OBJECTS_CURVE_IMP_H
  19 #define KIG_OBJECTS_CURVE_IMP_H
  20
  21 #include "object_imp.h"
  22
  23 /**
  24  * This class represents a curve: something which is composed of
  25  * points, like a line, a circle, a locus...
  26  */
  27 class CurveImp
  28   : public ObjectImp
  29 {
  30 public:
  31   typedef ObjectImp Parent;
  32
  33   /**
  34    * Returns the ObjectImpType representing the CurveImp type.
  35    */
  36   static const ObjectImpType* stype();
  37
  38   Coordinate attachPoint() const;
  39
  40   // param is between 0 and 1.  Note that 0 and 1 should be the
  41   // end-points.  E.g. for a Line, getPoint(0) returns a more or less
  42   // infinite point.  getPoint(0.5) should return the point in the
  43   // middle.
  44   virtual double getParam( const Coordinate& point, const KigDocument& ) const = 0;
  45   // this should be the inverse function of getPoint().
  46   // Note that it should also do something reasonable when p is not on
  47   // the curve.  You can return an invalid Coordinate(
  48   // Coordinate::invalidCoord() ) if you need to in some cases.
  49   virtual const Coordinate getPoint( double param, const KigDocument& ) const = 0;
  50
  51   virtual CurveImp* copy() const = 0;
  52
  53   /**
  54    * Return whether this Curve contains the given point.  This is
  55    * implemented as a numerical approximation.  Implementations
  56    * can/should use the value test_threshold in common.h as a
  57    * threshold value.
  58    */
  59   virtual bool containsPoint( const Coordinate& p, const KigDocument& ) const = 0;
  60 };
  61
  62 #endif