Copy the KDE 3.5 branch to branches/trinity for new KDE 3.5 features.

BUG:215923


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdeedu@1054174 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

1 files changed, 550 insertions, 0 deletions

diff --git a/kig/objects/polygon_imp.cc b/kig/objects/polygon_imp.cc
new file mode 100644
index 00000000..08215bfb
--- /dev/null
+++ b/kig/objects/polygon_imp.cc
@@ -0,0 +1,550 @@
+// Copyright (C)  2004  Pino Toscano <toscano.pino@tiscali.it>
+
+// 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 "polygon_imp.h"
+
+#include "bogus_imp.h"
+#include "line_imp.h"
+#include "point_imp.h"
+
+#include "../misc/common.h"
+#include "../misc/coordinate.h"
+#include "../misc/kigpainter.h"
+#include "../misc/kigtransform.h"
+
+#include "../kig/kig_document.h"
+#include "../kig/kig_view.h"
+
+#include <klocale.h>
+
+#include <cmath>
+
+PolygonImp::PolygonImp( uint npoints, const std::vector<Coordinate>& points,
+                        const Coordinate& centerofmass )
+  : mnpoints( npoints ), mpoints( points ), mcenterofmass( centerofmass )
+{
+//  mpoints = points;
+}
+
+PolygonImp::PolygonImp( const std::vector<Coordinate>& points )
+{
+  uint npoints = points.size();
+  Coordinate centerofmassn = Coordinate( 0, 0 );
+
+  for ( uint i = 0; i < npoints; ++i )
+  {
+    centerofmassn += points[i];
+  }
+  mpoints = points;
+  mcenterofmass = centerofmassn/npoints;
+  mnpoints = npoints;
+}
+
+PolygonImp::~PolygonImp()
+{
+}
+
+Coordinate PolygonImp::attachPoint() const
+{
+  return mcenterofmass;
+}
+
+ObjectImp* PolygonImp::transform( const Transformation& t ) const
+{
+/*mp:
+ * any projective transformation makes sense for a polygon,
+ * since segments transform into segments (but see below...)
+ * of course regular polygons will no longer be
+ * regular if t is not homothetic.
+ * for projective transformations the polygon could transform to
+ * an unbounded nonconnected polygon; this happens if some side
+ * of the polygon crosses the critical line that maps to infinity
+ * this can be easily checked using the getProjectiveIndicator
+ * function
+ */
+//  if ( ! t.isHomothetic() )
+//    return new InvalidImp();
+
+  if ( ! t.isAffine() )     /* in this case we need a more extensive test */
+  {
+    double maxp = -1.0;
+    double minp = 1.0;
+    for ( uint i = 0; i < mpoints.size(); ++i )
+    {
+      double p = t.getProjectiveIndicator( mpoints[i] );
+      if ( p > maxp ) maxp = p;
+      if ( p < minp ) minp = p;
+    }
+    if ( maxp > 0 && minp < 0 ) return new InvalidImp;
+  }
+  std::vector<Coordinate> np;
+  for ( uint i = 0; i < mpoints.size(); ++i )
+  {
+    Coordinate nc = t.apply( mpoints[i] );
+    if ( !nc.valid() )
+      return new InvalidImp;
+    np.push_back( nc );
+  }
+  return new PolygonImp( np );
+}
+
+void PolygonImp::draw( KigPainter& p ) const
+{
+  p.drawPolygon( mpoints );
+}
+
+bool PolygonImp::isInPolygon( const Coordinate& p ) const
+{
+  // (algorithm sent to me by domi)
+  // We intersect with the horizontal ray from point to the right and
+  // count the number of intersections.  That, along with some
+  // minor optimalisations of the intersection test..
+  bool inside_flag = false;
+  double cx = p.x;
+  double cy = p.y;
+
+  Coordinate prevpoint = mpoints.back();
+  bool prevpointbelow = mpoints.back().y >= cy;
+  for ( uint i = 0; i < mpoints.size(); ++i )
+  {
+    Coordinate point = mpoints[i];
+    bool pointbelow = point.y >= cy;
+    if ( prevpointbelow != pointbelow )
+    {
+      // possibility of intersection: points on different side from
+      // the X axis
+      //bool rightofpt = point.x >= cx;
+      // mp: we need to be a little bit more conservative here, in
+      // order to treat properly the case when the point is on the
+      // boundary
+      //if ( rightofpt == ( prevpoint.x >= cx ) )
+      if ( ( point.x - cx )*(prevpoint.x - cx ) > 0 )
+      {
+        // points on same side of Y axis -> easy to test intersection
+        // intersection iff one point to the right of c
+        if ( point.x >= cx )
+          inside_flag = !inside_flag;
+      }
+      else
+      {
+        // points on different sides of Y axis -> we need to calculate
+        // the intersection.
+        // mp: we want to check if the point is on the boundary, and
+        // return false in such case
+        double num = ( point.y - cy )*( prevpoint.x - point.x );
+        double den = prevpoint.y - point.y;
+	if ( num == den*( point.x - cx ) ) return false;
+        if ( num/den <= point.x - cx )
+          inside_flag = !inside_flag;
+      }
+    }
+    prevpoint = point;
+    prevpointbelow = pointbelow;
+  }
+  return inside_flag;
+}
+#define selectpolygonwithinside 1
+#ifdef selectpolygonwithinside
+bool PolygonImp::contains( const Coordinate& p, int, const KigWidget& ) const
+{
+  return isInPolygon( p );
+}
+#else
+bool PolygonImp::contains( const Coordinate& p, int width, const KigWidget& w ) const
+{
+  bool ret = false;
+  uint reduceddim = mpoints.size() - 1;
+  for ( uint i = 0; i < reduceddim; ++i )
+  {
+    ret |= isOnSegment( p, mpoints[i], mpoints[i+1], w.screenInfo().normalMiss( width ) );
+  }
+  ret |= isOnSegment( p, mpoints[reduceddim], mpoints[0], w.screenInfo().normalMiss( width ) );
+
+  return ret;
+}
+#endif
+
+bool PolygonImp::inRect( const Rect& r, int width, const KigWidget& w ) const
+{
+  bool ret = false;
+  uint reduceddim = mpoints.size() - 1;
+  for ( uint i = 0; i < reduceddim; ++i )
+  {
+    SegmentImp* s = new SegmentImp( mpoints[i], mpoints[i+1] );
+    ret |= lineInRect( r, mpoints[i], mpoints[i+1], width, s, w );
+    delete s;
+    s = 0;
+  }
+  SegmentImp* t = new SegmentImp( mpoints[reduceddim], mpoints[0] );
+  ret |= lineInRect( r, mpoints[reduceddim], mpoints[0], width, t, w );
+  delete t;
+  t = 0;
+
+  return ret;
+}
+
+bool PolygonImp::valid() const
+{
+  return true;
+}
+
+const uint PolygonImp::numberOfProperties() const
+{
+  return Parent::numberOfProperties() + 5;
+}
+
+const QCStringList PolygonImp::propertiesInternalNames() const
+{
+  QCStringList l = Parent::propertiesInternalNames();
+  l += "polygon-number-of-sides";
+  l += "polygon-perimeter";
+  l += "polygon-surface";
+  l += "polygon-center-of-mass";
+  l += "polygon-winding-number";
+  assert( l.size() == PolygonImp::numberOfProperties() );
+  return l;
+}
+
+const QCStringList PolygonImp::properties() const
+{
+  QCStringList l = Parent::properties();
+  l += I18N_NOOP( "Number of sides" );
+  l += I18N_NOOP( "Perimeter" );
+  l += I18N_NOOP( "Surface" );
+  l += I18N_NOOP( "Center of Mass of the Vertices" );
+  l += I18N_NOOP( "Winding Number" );
+  assert( l.size() == PolygonImp::numberOfProperties() );
+  return l;
+}
+
+const ObjectImpType* PolygonImp::impRequirementForProperty( uint which ) const
+{
+  if ( which < Parent::numberOfProperties() )
+    return Parent::impRequirementForProperty( which );
+  else return PolygonImp::stype();
+}
+
+const char* PolygonImp::iconForProperty( uint which ) const
+{
+  assert( which < PolygonImp::numberOfProperties() );
+  if ( which < Parent::numberOfProperties() )
+    return Parent::iconForProperty( which );
+  else if ( which == Parent::numberOfProperties() )
+    return "en"; // number of sides
+  else if ( which == Parent::numberOfProperties() + 1 )
+    return "circumference"; // perimeter
+  else if ( which == Parent::numberOfProperties() + 2 )
+    return "areaCircle"; // surface
+  else if ( which == Parent::numberOfProperties() + 3 )
+    return "point"; // center of mass
+  else if ( which == Parent::numberOfProperties() + 4 )
+    return "w"; // winding number
+  else assert( false );
+  return "";
+}
+
+ObjectImp* PolygonImp::property( uint which, const KigDocument& w ) const
+{
+  assert( which < PolygonImp::numberOfProperties() );
+  if ( which < Parent::numberOfProperties() )
+    return Parent::property( which, w );
+  else if ( which == Parent::numberOfProperties() )
+  {
+    // number of points
+    return new IntImp( mnpoints );
+  }
+  else if ( which == Parent::numberOfProperties() + 1)
+  {
+    double circumference = 0.;
+    // circumference
+    for ( uint i = 0; i < mpoints.size(); ++i )
+    {
+      uint prev = ( i + mpoints.size() - 1 ) % mpoints.size();
+      circumference += ( mpoints[i] - mpoints[prev] ).length();
+    }
+    return new DoubleImp( circumference );
+  }
+  else if ( which == Parent::numberOfProperties() + 2)
+  {
+    int wn = windingNumber ();  // not able to compute area for such polygons...
+    if ( wn < 0 ) wn = -wn;
+    if ( wn != 1 ) return new InvalidImp;
+    double surface2 = 0.0;
+    Coordinate prevpoint = mpoints.back();
+    for ( uint i = 0; i < mpoints.size(); ++i )
+    {
+      Coordinate point = mpoints[i];
+      surface2 += ( point.x - prevpoint.x ) * ( point.y + prevpoint.y ); 
+      prevpoint = point;
+    }
+    return new DoubleImp( fabs( surface2 / 2 ) );
+  }
+  else if ( which == Parent::numberOfProperties() + 3 )
+  {
+    return new PointImp( mcenterofmass );
+  }
+  else if ( which == Parent::numberOfProperties() + 4 )
+  {
+    // winding number
+    return new IntImp( windingNumber() );
+  }
+  else assert( false );
+  return new InvalidImp;
+}
+
+const std::vector<Coordinate> PolygonImp::points() const
+{
+  std::vector<Coordinate> np;
+  np.reserve( mpoints.size() );
+  std::copy( mpoints.begin(), mpoints.end(), std::back_inserter( np ) );
+  return np;
+}
+
+const uint PolygonImp::npoints() const
+{
+  return mnpoints;
+}
+
+PolygonImp* PolygonImp::copy() const
+{
+  return new PolygonImp( mpoints );
+}
+
+void PolygonImp::visit( ObjectImpVisitor* vtor ) const
+{
+  vtor->visit( this );
+}
+
+bool PolygonImp::equals( const ObjectImp& rhs ) const
+{
+  return rhs.inherits( PolygonImp::stype() ) &&
+    static_cast<const PolygonImp&>( rhs ).points() == mpoints;
+}
+
+const ObjectImpType* PolygonImp::stype()
+{
+  static const ObjectImpType t(
+    Parent::stype(), "polygon",
+    I18N_NOOP( "polygon" ),
+    I18N_NOOP( "Select this polygon" ),
+    I18N_NOOP( "Select polygon %1" ),
+    I18N_NOOP( "Remove a Polygon" ),
+    I18N_NOOP( "Add a Polygon" ),
+    I18N_NOOP( "Move a Polygon" ),
+    I18N_NOOP( "Attach to this polygon" ),
+    I18N_NOOP( "Show a Polygon" ),
+    I18N_NOOP( "Hide a Polygon" )
+    );
+
+  return &t;
+}
+
+const ObjectImpType* PolygonImp::stype3()
+{
+  static const ObjectImpType t3(
+    PolygonImp::stype(), "triangle",
+    I18N_NOOP( "triangle" ),
+    I18N_NOOP( "Select this triangle" ),
+    I18N_NOOP( "Select triangle %1" ),
+    I18N_NOOP( "Remove a Triangle" ),
+    I18N_NOOP( "Add a Triangle" ),
+    I18N_NOOP( "Move a Triangle" ),
+    I18N_NOOP( "Attach to this triangle" ),
+    I18N_NOOP( "Show a Triangle" ),
+    I18N_NOOP( "Hide a Triangle" )
+    );
+
+  return &t3;
+}
+
+const ObjectImpType* PolygonImp::stype4()
+{
+  static const ObjectImpType t4(
+    PolygonImp::stype(), "quadrilateral",
+    I18N_NOOP( "quadrilateral" ),
+    I18N_NOOP( "Select this quadrilateral" ),
+    I18N_NOOP( "Select quadrilateral %1" ),
+    I18N_NOOP( "Remove a Quadrilateral" ),
+    I18N_NOOP( "Add a Quadrilateral" ),
+    I18N_NOOP( "Move a Quadrilateral" ),
+    I18N_NOOP( "Attach to this quadrilateral" ),
+    I18N_NOOP( "Show a Quadrilateral" ),
+    I18N_NOOP( "Hide a Quadrilateral" )
+    );
+
+  return &t4;
+}
+
+const ObjectImpType* PolygonImp::type() const
+{
+  uint n = mpoints.size();
+
+  if ( n == 3 ) return PolygonImp::stype3();
+  if ( n == 4 ) return PolygonImp::stype4();
+  return PolygonImp::stype();
+}
+
+bool PolygonImp::isPropertyDefinedOnOrThroughThisImp( uint which ) const
+{
+  assert( which < PolygonImp::numberOfProperties() );
+  if ( which < Parent::numberOfProperties() )
+    return Parent::isPropertyDefinedOnOrThroughThisImp( which );
+  return false;
+}
+
+Rect PolygonImp::surroundingRect() const
+{
+  Rect r( 0., 0., 0., 0. );
+  for ( uint i = 0; i < mpoints.size(); ++i )
+  {
+    r.setContains( mpoints[i] );
+  }
+  return r;
+}
+
+int PolygonImp::windingNumber() const
+{
+  /*
+   * this is defined as the sum of the external angles while at
+   * all vertices, then normalized by 2pi.  The external angle
+   * is the angle we steer at each vertex while we walk along the
+   * boundary of the polygon.
+   * In the end we only need to count how many time we cross the (1,0)
+   * direction (positive x-axis) with a positive sign if we cross while
+   * steering left and a negative sign viceversa
+   */
+
+  int winding = 0;
+  uint npoints = mpoints.size();
+  Coordinate prevside = mpoints[0] - mpoints[npoints-1];
+  for ( uint i = 0; i < npoints; ++i )
+  {
+    uint nexti = i + 1;
+    if ( nexti >= npoints ) nexti = 0;
+    Coordinate side = mpoints[nexti] - mpoints[i];
+    double vecprod = side.x*prevside.y - side.y*prevside.x;
+    int steeringdir = ( vecprod > 0 ) ? 1 : -1;
+    if ( vecprod == 0.0 || side.y*prevside.y > 0 )
+    {
+      prevside = side;
+      continue;   // cannot cross the (1,0) direction
+    }
+    if ( side.y*steeringdir < 0 && prevside.y*steeringdir >= 0 )
+      winding -= steeringdir;
+    prevside = side;
+  }
+  return winding;
+}
+
+bool PolygonImp::isMonotoneSteering() const
+{
+  /*
+   * returns true if while walking along the boundary,
+   * steering is always in the same direction
+   */
+
+  uint npoints = mpoints.size();
+  Coordinate prevside = mpoints[0] - mpoints[npoints-1];
+  int prevsteeringdir = 0;
+  for ( uint i = 0; i < npoints; ++i )
+  {
+    uint nexti = i + 1;
+    if ( nexti >= npoints ) nexti = 0;
+    Coordinate side = mpoints[nexti] - mpoints[i];
+    double vecprod = side.x*prevside.y - side.y*prevside.x;
+    int steeringdir = ( vecprod > 0 ) ? 1 : -1;
+    if ( vecprod == 0.0 )
+    {
+      prevside = side;
+      continue;   // going straight
+    }
+    if ( prevsteeringdir*steeringdir < 0 ) return false;
+    prevside = side;
+    prevsteeringdir = steeringdir;
+  }
+  return true;
+}
+
+bool PolygonImp::isConvex() const
+{
+  if ( ! isMonotoneSteering() ) return false;
+  int winding = windingNumber();
+  if ( winding < 0 ) winding = -winding;
+  assert ( winding > 0 );
+  return winding == 1;
+}
+
+std::vector<Coordinate> computeConvexHull( const std::vector<Coordinate>& points )
+{
+  /*
+   * compute the convex hull of the set of points, the resulting list
+   * is the vertices of the resulting polygon listed in a counter clockwise
+   * order.  This algorithm is on order n^2, probably suboptimal, but
+   * we don't expect to have large values for n.
+   */
+
+  if ( points.size() < 3 ) return points;
+  std::vector<Coordinate> worklist = points;
+  std::vector<Coordinate> result;
+
+  double ymin = worklist[0].y;
+  uint imin = 0;
+  for ( uint i = 1; i < worklist.size(); ++i )
+  {
+    if ( worklist[i].y < ymin )
+    {
+      ymin = worklist[i].y;
+      imin = i;
+    }
+  }
+
+  // worklist[imin] is definitely on the convex hull, let's start from there
+  result.push_back( worklist[imin] );
+  Coordinate startpoint = worklist[imin];
+  Coordinate apoint = worklist[imin];
+  double aangle = 0.0;
+
+  while ( ! worklist.empty() )
+  {
+    int besti = -1;
+    double anglemin = 10000.0;
+    for ( uint i = 0; i < worklist.size(); ++i )
+    {
+      if ( worklist[i] == apoint ) continue;
+      Coordinate v = worklist[i] - apoint;
+      double angle = std::atan2( v.y, v.x );
+      while ( angle < aangle ) angle += 2*M_PI;
+      if ( angle < anglemin )
+      {   // found a better point
+        besti = i;
+        anglemin = angle;
+      }
+    }
+
+    if ( besti < 0 ) return result;   // this happens, e.g. if all points coincide
+    apoint = worklist[besti];
+    aangle = anglemin;
+    if ( apoint == startpoint )
+    {
+      return result;
+    }
+    result.push_back( apoint );
+    worklist.erase( worklist.begin() + besti, worklist.begin() + besti + 1 );
+  }
+  assert( false );
+  return result;
+}