line_imp.cc

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// Copyright (C)  2002  Dominique Devriese <devriese@kde.org>

// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.

// This program 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 General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
// 02110-1301, USA.

#include "line_imp.h"

#include "bogus_imp.h"
#include "point_imp.h"

#include "../misc/rect.h"
#include "../misc/common.h"
#include "../misc/kigtransform.h"
#include "../misc/kigpainter.h"
#include "../misc/equation.h"
#include "../kig/kig_view.h"

#include <klocale.h>

#include <cmath>
using namespace std;

AbstractLineImp::AbstractLineImp( const Coordinate& a, const Coordinate& b )
  : mdata( a, b )
{
}

AbstractLineImp::~AbstractLineImp()
{
}

bool AbstractLineImp::inRect( const Rect& r, int width, const KigWidget& w ) const
{
  return lineInRect( r, mdata.a, mdata.b, width, this, w );
}

int AbstractLineImp::numberOfProperties() const
{
  return Parent::numberOfProperties() + 2;
}

const ObjectImpType* AbstractLineImp::impRequirementForProperty( int which ) const
{
  if ( which < Parent::numberOfProperties() )
    return Parent::impRequirementForProperty( which );
  else return AbstractLineImp::stype();
}

const char* AbstractLineImp::iconForProperty( int which ) const
{
  if ( which < Parent::numberOfProperties() )
    return Parent::iconForProperty( which );
  if ( which == Parent::numberOfProperties() )
    return "slope"; // slope
  if ( which == Parent::numberOfProperties() + 1 )
    return "kig_text"; // equation
  else assert( false );
  return "";
}

ObjectImp* AbstractLineImp::property( int which, const KigDocument& w ) const
{
  if ( which < Parent::numberOfProperties() )
    return Parent::property( which, w );
  if ( which == Parent::numberOfProperties() )
    return new DoubleImp( slope() );
  if ( which == Parent::numberOfProperties() + 1 )
    return new StringImp( equationString() );
  else assert( false );
  return new InvalidImp;
}

const QByteArrayList AbstractLineImp::propertiesInternalNames() const
{
  QByteArrayList l = Parent::propertiesInternalNames();
  l << "slope";
  l << "equation";
  assert( l.size() == AbstractLineImp::numberOfProperties() );
  return l;
}

const QByteArrayList AbstractLineImp::properties() const
{
  QByteArrayList l = Parent::properties();
  l << I18N_NOOP( "Slope" );
  l << I18N_NOOP( "Equation" );
  assert( l.size() == AbstractLineImp::numberOfProperties() );
  return l;
}

int SegmentImp::numberOfProperties() const
{
  return Parent::numberOfProperties() + 5;
}

const QByteArrayList SegmentImp::propertiesInternalNames() const
{
  QByteArrayList s = Parent::propertiesInternalNames();
  s << "length";
  s << "mid-point";
  s << "support";
  s << "end-point-A";
  s << "end-point-B";
  assert( s.size() == SegmentImp::numberOfProperties() );
  return s;
}

const QByteArrayList SegmentImp::properties() const
{
  QByteArrayList s = Parent::properties();
  s << I18N_NOOP( "Length" );
  s << I18N_NOOP( "Mid Point" );
  s << I18N_NOOP( "Support Line" );
  s << I18N_NOOP( "First End Point" );
  s << I18N_NOOP( "Second End Point" );
  assert( s.size() == SegmentImp::numberOfProperties() );
  return s;
}

const ObjectImpType* SegmentImp::impRequirementForProperty( int which ) const
{
  if ( which < Parent::numberOfProperties() )
    return Parent::impRequirementForProperty( which );
  else return SegmentImp::stype();
}

const char* SegmentImp::iconForProperty( int which ) const
{
  int pnum = 0;
  if ( which < Parent::numberOfProperties() )
    return Parent::iconForProperty( which );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return "distance"; // length
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return "segment_midpoint"; // mid point
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return ""; // support line
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return "endpoint1"; // mid point
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return "endpoint2"; // mid point
  else assert( false );
  return "";
}

ObjectImp* SegmentImp::property( int which, const KigDocument& w ) const
{
  int pnum = 0;

  if ( which < Parent::numberOfProperties() )
    return Parent::property( which, w );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return new DoubleImp( mdata.dir().length() );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return new PointImp( ( mdata.a + mdata.b ) / 2 );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return new LineImp( mdata.a, mdata.b );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return new PointImp( mdata.a );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return new PointImp( mdata.b );
  else assert( false );
  return new InvalidImp;
}

int RayImp::numberOfProperties() const
{
  return Parent::numberOfProperties() + 2;
}

const QByteArrayList RayImp::propertiesInternalNames() const
{
  QByteArrayList s = Parent::propertiesInternalNames();
  s << "support";
  s << "end-point-A";
  assert( s.size() == RayImp::numberOfProperties() );
  return s;
}

const QByteArrayList RayImp::properties() const
{
  QByteArrayList s = Parent::properties();
  s << I18N_NOOP( "Support Line" );
  s << I18N_NOOP( "End Point" );
  assert( s.size() == RayImp::numberOfProperties() );
  return s;
}

const ObjectImpType* RayImp::impRequirementForProperty( int which ) const
{
  if ( which < Parent::numberOfProperties() )
    return Parent::impRequirementForProperty( which );
  else return RayImp::stype();
}

const char* RayImp::iconForProperty( int which ) const
{
  int pnum = 0;
  if ( which < Parent::numberOfProperties() )
    return Parent::iconForProperty( which );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return ""; // support line
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return "endpoint1"; // end point
  else assert( false );
  return "";
}

ObjectImp* RayImp::property( int which, const KigDocument& w ) const
{
  int pnum = 0;

  if ( which < Parent::numberOfProperties() )
    return Parent::property( which, w );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return new LineImp( mdata.a, mdata.b );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return new PointImp( mdata.a );
  else assert( false );
  return new InvalidImp;
}

double AbstractLineImp::slope() const
{
  Coordinate diff = mdata.dir();
  return diff.y / diff.x;
}

const QString AbstractLineImp::equationString() const
{
  Coordinate p = mdata.a;
  Coordinate q = mdata.b;

  EquationString ret = EquationString( "" );

  double a = q.y - p.y;
  double b = p.x - q.x;
  double c = q.x*p.y - q.y*p.x;

  bool needsign = false;
  if ( fabs( b ) < 1e-6*fabs( a ) )
  {
    ret.addTerm( 1.0, ret.x(), needsign );
    ret.addTerm( b/a, ret.y(), needsign );
    ret.addTerm( c/a, "", needsign );
    ret.append( " = 0" );
    return ret;
  }

  ret.append( "y = " );
  ret.addTerm( -a/b, ret.x(), needsign );
  ret.addTerm( -c/b, "", needsign );
  if ( ! needsign ) ret.append( "0" );
//  double m = ( q.y - p.y ) / ( q.x - p.x );
//  double r = - ( q.y - p.y ) * p.x / ( q.x - p.x ) + p.y;
//
//  QString ret = QString::fromUtf8( "y = %1x " ) +
//                QString::fromUtf8( r > 0 ? "+" : "-" ) +
//                QString::fromUtf8( " %2" );
//
//  ret = ret.arg( m, 0, 'g', 3 );
//  ret = ret.arg( abs( r ), 0, 'g', 3 );

  return ret;
}

void SegmentImp::draw( KigPainter& p ) const
{
  p.drawSegment( mdata );
}

bool SegmentImp::contains( const Coordinate& p, int width, const KigWidget& w ) const
{
  return internalContainsPoint( p, w.screenInfo().normalMiss( width ) );
}

void RayImp::draw( KigPainter& p ) const
{
  p.drawRay( mdata );
}

bool RayImp::contains( const Coordinate& p, int width, const KigWidget& w ) const
{
  return internalContainsPoint( p, w.screenInfo().normalMiss( width ) );
}

void LineImp::draw( KigPainter& p ) const
{
  p.drawLine( mdata );
}

bool LineImp::contains( const Coordinate& p, int width, const KigWidget& w ) const
{
  return internalContainsPoint( p, w.screenInfo().normalMiss( width ) );
}

SegmentImp::SegmentImp( const Coordinate& a, const Coordinate& b )
  : AbstractLineImp( a, b )
{
}

RayImp::RayImp( const Coordinate& a, const Coordinate& b )
  : AbstractLineImp( a, b )
{
}

LineImp::LineImp( const Coordinate& a, const Coordinate& b )
  : AbstractLineImp( a, b )
{
}

SegmentImp* SegmentImp::copy() const
{
  return new SegmentImp( mdata );
}

RayImp* RayImp::copy() const
{
  return new RayImp( mdata );
}

LineImp* LineImp::copy() const
{
  return new LineImp( mdata );
}

const Coordinate SegmentImp::getPoint( double param, const KigDocument& ) const
{
  return mdata.a + mdata.dir()*param;
}

double SegmentImp::getParam( const Coordinate& p, const KigDocument& ) const
{
  Coordinate pt = calcPointOnPerpend( data(), p );
  pt = calcIntersectionPoint( data(), LineData( p, pt ) );
  // if pt is over the end of the segment ( i.e. it's on the line
  // which the segment is a part of, but not of the segment itself..;
  // ) we set it to one of the end points of the segment...
  if ((pt - mdata.a).length() > mdata.dir().length() )
    pt = mdata.b;
  else if ( (pt- mdata.b).length() > mdata.dir().length() )
    pt = mdata.a;
  if (mdata.b == mdata.a) return 0;
  return ((pt - mdata.a).length())/(mdata.dir().length());
}

LineData AbstractLineImp::data() const
{
  return mdata;
}

const Coordinate RayImp::getPoint( double param, const KigDocument& ) const
{
  param = 1.0/param - 1.0;
  return mdata.a + mdata.dir()*param;
}

double RayImp::getParam( const Coordinate& p, const KigDocument& ) const
{
  const LineData ld = data();
  Coordinate pt = calcPointOnPerpend( ld, p );
  pt = calcIntersectionPoint( ld, LineData( p, pt ));
  // if pt is over the end of the ray ( i.e. it's on the line
  // which the ray is a part of, but not of the ray itself..;
  // ) we set it to the start point of the ray...
  Coordinate dir = ld.dir();
  pt -= ld.a;
  double param;
  if ( dir.x != 0 ) param = pt.x / dir.x;
  else if ( dir.y != 0 ) param = pt.y / dir.y;
  else param = 0.;
  if ( param < 0. ) param = 0.;

  // mp:  let's try with 1/(x+1),  this reverses the mapping, but
  // should allow to take advantage of the tightness of floating point
  // numbers near zero, in order to get more possible positions near
  // infinity

  param = 1./( param + 1. );

  assert( param >= 0. && param <= 1. );
  return param;
}

const Coordinate LineImp::getPoint( double p, const KigDocument& ) const
{
  // inspired upon KSeg

  // we need to spread the points over the line, it should also come near
  // the (infinite) end of the line, but most points should be near
  // the two points we contain...
  if ( p <= 0. ) p = 1e-6;
  if ( p >= 1. ) p = 1 - 1e-6;
  p = 2*p - 1;
  if (p > 0) p = p/(1 - p);
  else p = p/(1 + p);
//  p *= 1024;    // such multiplying factor could be useful in order to
  // have more points near infinity, at the expense of
  // points near ma and mb
  return mdata.a + p*mdata.dir();
}

double LineImp::getParam( const Coordinate& point, const KigDocument& ) const
{
  // somewhat the reverse of getPoint, although it also supports
  // points not on the line...

  Coordinate pa = point - mdata.a;
  Coordinate ba = mdata.dir();
  double balsq = ba.x*ba.x + ba.y*ba.y;
  assert (balsq > 0);

  double p = (pa.x*ba.x + pa.y*ba.y)/balsq;
//  p /= 1024;
  if (p > 0) p = p/(1+p);
  else p = p/(1-p);

  return 0.5*(p + 1);
}

ObjectImp* SegmentImp::transform( const Transformation& t ) const
{
  if ( ! t.isAffine() )    /* we need to check the position of the two points */
  {
    if ( t.getProjectiveIndicator( mdata.a ) *
         t.getProjectiveIndicator( mdata.b ) < 0 )
      return new InvalidImp();
  }
  Coordinate na = t.apply( mdata.a );
  Coordinate nb = t.apply( mdata.b );
  if( na.valid() && nb.valid() ) return new SegmentImp( na, nb );
  else return new InvalidImp();
}

ObjectImp* LineImp::transform( const Transformation& t ) const
{
  Coordinate na = t.apply( mdata.a );
  Coordinate nb = t.apply( mdata.b );
  if ( na.valid() && nb.valid() ) return new LineImp( na, nb );
  else return new InvalidImp();
}

ObjectImp* RayImp::transform( const Transformation& t ) const
{
  if ( ! t.isAffine() )    /* we need to check the position of the two points */
  {
    double pa = t.getProjectiveIndicator( mdata.a );
    double pb = t.getProjectiveIndicator( mdata.b );
    if ( pa < 0 ) pb = -pb;
    if ( pb < fabs (pa) ) return new InvalidImp();
    Coordinate na = t.apply( mdata.a );
    Coordinate nb = t.apply0( mdata.b - mdata.a );
    if ( na.valid() && nb.valid() ) return new SegmentImp( na, nb );
    else return new InvalidImp();
  }
  Coordinate na = t.apply( mdata.a );
  Coordinate nb = t.apply( mdata.b );
  if ( na.valid() && nb.valid() ) return new RayImp( na, nb );
  else return new InvalidImp();
}

AbstractLineImp::AbstractLineImp( const LineData& d )
  : mdata( d )
{
}

SegmentImp::SegmentImp( const LineData& d )
  : AbstractLineImp( d )
{
}

RayImp::RayImp( const LineData& d )
  : AbstractLineImp( d )
{
}

LineImp::LineImp( const LineData& d )
  : AbstractLineImp( d )
{
}

double SegmentImp::length() const
{
  return mdata.length();
}

void SegmentImp::visit( ObjectImpVisitor* vtor ) const
{
  vtor->visit( this );
}

void RayImp::visit( ObjectImpVisitor* vtor ) const
{
  vtor->visit( this );
}

void LineImp::visit( ObjectImpVisitor* vtor ) const
{
  vtor->visit( this );
}

bool AbstractLineImp::equals( const ObjectImp& rhs ) const
{
  return rhs.type() == type() &&
    static_cast<const AbstractLineImp&>( rhs ).data() == data();
}

const ObjectImpType* AbstractLineImp::stype()
{
  static const ObjectImpType t(
    Parent::stype(), "line", I18N_NOOP( "line" ),
    I18N_NOOP( "Select a Line" ), 0, 0, 0, 0, 0, 0, 0 );
  return &t;
}

const ObjectImpType* LineImp::stype()
{
  static const ObjectImpType t(
    Parent::stype(), "line",
    I18N_NOOP( "line" ),
    I18N_NOOP( "Select this line" ),
    I18N_NOOP( "Select line %1" ),
    I18N_NOOP( "Remove a Line" ),
    I18N_NOOP( "Add a Line" ),
    I18N_NOOP( "Move a Line" ),
    I18N_NOOP( "Attach to this line" ),
    I18N_NOOP( "Show a Line" ),
    I18N_NOOP( "Hide a Line" )
    );
  return &t;
}

const ObjectImpType* SegmentImp::stype()
{
  static const ObjectImpType t(
    Parent::stype(), "segment",
    I18N_NOOP( "segment" ),
    I18N_NOOP( "Select this segment" ),
    I18N_NOOP( "Select segment %1" ),
    I18N_NOOP( "Remove a Segment" ),
    I18N_NOOP( "Add a Segment" ),
    I18N_NOOP( "Move a Segment" ),
    I18N_NOOP( "Attach to this segment" ),
    I18N_NOOP( "Show a Segment" ),
    I18N_NOOP( "Hide a Segment" )
    );
  return &t;
}

const ObjectImpType* RayImp::stype()
{
  static const ObjectImpType t(
    Parent::stype(), "ray",
    I18N_NOOP( "half-line" ),
    I18N_NOOP( "Select this half-line" ),
    I18N_NOOP( "Select half-line %1" ),
    I18N_NOOP( "Remove a Half-Line" ),
    I18N_NOOP( "Add a Half-Line" ),
    I18N_NOOP( "Move a Half-Line" ),
    I18N_NOOP( "Attach to this half-line" ),
    I18N_NOOP( "Show a Half-Line" ),
    I18N_NOOP( "Hide a Half-Line" )
    );
  return &t;
}

const ObjectImpType* SegmentImp::type() const
{
  return SegmentImp::stype();
}

const ObjectImpType* RayImp::type() const
{
  return RayImp::stype();
}

const ObjectImpType* LineImp::type() const
{
  return LineImp::stype();
}

bool SegmentImp::containsPoint( const Coordinate& p, const KigDocument& ) const
{
  return internalContainsPoint( p, test_threshold );
}

bool SegmentImp::internalContainsPoint( const Coordinate& p, double threshold ) const
{
  return isOnSegment( p, mdata.a, mdata.b, threshold );
}

bool RayImp::containsPoint( const Coordinate& p, const KigDocument& ) const
{
  return internalContainsPoint( p, test_threshold );
}

bool RayImp::internalContainsPoint( const Coordinate& p, double threshold ) const
{
  return isOnRay( p, mdata.a, mdata.b, threshold );
}

bool LineImp::containsPoint( const Coordinate& p, const KigDocument& ) const
{
  return internalContainsPoint( p, test_threshold );
}

bool LineImp::internalContainsPoint( const Coordinate& p, double threshold ) const
{
  return isOnLine( p, mdata.a, mdata.b, threshold );
}

bool AbstractLineImp::isPropertyDefinedOnOrThroughThisImp( int which ) const
{
  int pnum = 0;

  if ( which < Parent::numberOfProperties() )
    return Parent::isPropertyDefinedOnOrThroughThisImp( which );
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return false;
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return true;
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return true;
  else if ( which == Parent::numberOfProperties() + pnum++ )
    return true;
  else assert( false );
  return false;
}

Rect SegmentImp::surroundingRect() const
{
  return Rect( mdata.a, mdata.b );
}

Rect RayImp::surroundingRect() const
{
  return Rect::invalidRect();
}

Rect LineImp::surroundingRect() const
{
  return Rect::invalidRect();
}