int
main(int argc, char ** argv){
typedef Z2i::Point Point;
std::vector<Point> contour = PointListReader<Point>::getPointsFromFile("../Samples/contourS.sdp");
Board2D aBoard;
for (auto&& p :contour) {
aBoard << p;
}
aBoard.setPenColor(DGtal::Color::Red);
aBoard.setFillColor(DGtal::Color::Red);
aBoard.drawCircle(contour[30][0], contour[30][1],1);
unsigned int startIndex = 30;
typedef AlphaThickSegmentComputer< Z2i::Point > AlphaThickSegmentComputer2D;
AlphaThickSegmentComputer2D aComputer(5);
aComputer.init(contour.begin()+30);
while(aComputer.extendFront()){
}
aBoard << CustomStyle( aComputer.className(), new CustomColors( DGtal::Color::Blue, DGtal::Color::None ) );
aBoard << aComputer;
aBoard.saveEPS("resultTuto2.eps");
return 0;
}
/**
* Algorithms that computes the convex hull
* of a point set
*/
void convexHull()
{
//Digitization of a disk of radius 6
Ball2D<Z2i::Space> ball(Z2i::Point(0,0), 6);
Z2i::Domain domain(ball.getLowerBound(), ball.getUpperBound());
Z2i::DigitalSet pointSet(domain);
Shapes<Z2i::Domain>::euclideanShaper(pointSet, ball);
//! [Hull2D-Namespace]
using namespace functions::Hull2D;
//! [Hull2D-Namespace]
//! [Hull2D-Functor]
typedef InHalfPlaneBySimple3x3Matrix<Z2i::Point, DGtal::int64_t> Functor;
Functor functor;
//! [Hull2D-Functor]
{ //convex hull in counter-clockwise order
vector<Z2i::Point> res;
//! [Hull2D-StrictPredicateCCW]
typedef PredicateFromOrientationFunctor2<Functor, false, false> StrictPredicate;
StrictPredicate predicate( functor );
//! [Hull2D-StrictPredicateCCW]
//according to the last two template arguments, neither strictly negative values, nor zeros are accepted:
//the predicate returns 'true' only for strictly positive values returned by the underlying functor.
//! [Hull2D-AndrewAlgo]
andrewConvexHullAlgorithm( pointSet.begin(), pointSet.end(), back_inserter( res ), predicate );
//! [Hull2D-AndrewAlgo]
//![Hull2D-Caliper-computeBasic]
double th = DGtal::functions::Hull2D::computeHullThickness(res.begin(), res.end(), DGtal::functions::Hull2D::HorizontalVerticalThickness);
//![Hull2D-Caliper-computeBasic]
//![Hull2D-Caliper-computeAnti]
Z2i::Point antipodalP, antipodalQ, antipodalS;
th = DGtal::functions::Hull2D::computeHullThickness(res.begin(), res.end(), DGtal::functions::Hull2D::HorizontalVerticalThickness, antipodalP, antipodalQ, antipodalS);
//![Hull2D-Caliper-computeAnti]
trace.info() <<" ConvexHull HV thickness: " << th << std::endl;
//display
Board2D board;
drawPolygon( res.begin(), res.end(), board );
//![Hull2D-Caliper-display]
board.setPenColor(DGtal::Color::Red);
board.drawCircle( antipodalS[0], antipodalS[1], 0.2) ;
board.setPenColor(DGtal::Color::Blue);
board.drawCircle(antipodalP[0], antipodalP[1], 0.2);
board.drawCircle(antipodalQ[0], antipodalQ[1], 0.2);
board.drawLine(antipodalP[0], antipodalP[1], antipodalQ[0], antipodalQ[1]);
//![Hull2D-Caliper-display]
board.saveSVG( "ConvexHullCCW.svg" );
#ifdef WITH_CAIRO
board.saveCairo("ConvexHullCCW.png", Board2D::CairoPNG);
#endif
}
{ //convex hull in counter-clockwise order with all the points lying on the edges
vector<Z2i::Point> res;
//! [Hull2D-LargePredicateCCW]
typedef PredicateFromOrientationFunctor2<Functor, false, true> LargePredicate;
LargePredicate predicate( functor );
//! [Hull2D-LargePredicateCCW]
//according to the last template argument, zeros are accepted so that
//the predicate returns 'true' for all the positive values returned by the underlying functor.
//andrew algorithm
andrewConvexHullAlgorithm( pointSet.begin(), pointSet.end(), back_inserter( res ), predicate );
//display
Board2D board;
drawPolygon( res.begin(), res.end(), board );
board.saveSVG( "ConvexHullCCWWithPointsOnEdges.svg" );
#ifdef WITH_CAIRO
board.saveCairo("ConvexHullCCWWithPointsOnEdges.png", Board2D::CairoPNG);
#endif
}
{ //convex hull in clockwise order
vector<Z2i::Point> res;
//! [Hull2D-StrictPredicateCW]
typedef PredicateFromOrientationFunctor2<Functor, true, false> StrictPredicate;
StrictPredicate predicate( functor );
//! [Hull2D-StrictPredicateCW]
//according to the last two argument template,
//the predicate returns 'true' only for strictly negative values returned by the underlying functor.
//andrew algorithm
andrewConvexHullAlgorithm( pointSet.begin(), pointSet.end(), back_inserter( res ), predicate );
//display
Board2D board;
drawPolygon( res.begin(), res.end(), board );
board.saveSVG( "ConvexHullCW.svg" );
#ifdef WITH_CAIRO
board.saveCairo("ConvexHullCW.png", Board2D::CairoPNG);
#endif
}
{ //convex hull in counter-clockwise order
vector<Z2i::Point> res;
//geometric predicate
typedef PredicateFromOrientationFunctor2<Functor, false, false> StrictPredicate;
StrictPredicate predicate( functor );
//! [Hull2D-GrahamAlgo]
grahamConvexHullAlgorithm( pointSet.begin(), pointSet.end(), back_inserter( res ), predicate );
//! [Hull2D-GrahamAlgo]
//display
Board2D board;
drawPolygon( res.begin(), res.end(), board );
board.saveSVG( "ConvexHullCCWbis.svg" );
#ifdef WITH_CAIRO
board.saveCairo("ConvexHullCCWbis.png", Board2D::CairoPNG);
#endif
}
{ //convex hull of a simple polygonal line that is not weakly externally visible
vector<Z2i::Point> polygonalLine;
polygonalLine.push_back(Z2i::Point(0,0));
polygonalLine.push_back(Z2i::Point(0,4));
polygonalLine.push_back(Z2i::Point(1,4));
polygonalLine.push_back(Z2i::Point(1,1));
polygonalLine.push_back(Z2i::Point(3,1));
polygonalLine.push_back(Z2i::Point(2,2));
polygonalLine.push_back(Z2i::Point(3,4));
polygonalLine.push_back(Z2i::Point(4,4));
polygonalLine.push_back(Z2i::Point(4,0));
vector<Z2i::Point> resGraham, res;
typedef PredicateFromOrientationFunctor2<Functor, false, false> StrictPredicate;
StrictPredicate predicate( functor );
closedGrahamScanFromAnyPoint( polygonalLine.begin(), polygonalLine.end(), back_inserter( resGraham ), predicate );
//! [Hull2D-OnLineMelkmanAlgo]
DGtal::MelkmanConvexHull<Z2i::Point, Functor> ch( functor );
for (std::vector<Z2i::Point>::const_iterator
it = polygonalLine.begin(),
itEnd = polygonalLine.end();
it != itEnd; ++it)
ch.add( *it );
//! [Hull2D-OnLineMelkmanAlgo]
//! [Hull2D-OffLineMelkmanAlgo]
melkmanConvexHullAlgorithm( polygonalLine.begin(), polygonalLine.end(), back_inserter( res ), functor );
//! [Hull2D-OffLineMelkmanAlgo]
//display
Board2D board;
drawPolygon( polygonalLine.begin(), polygonalLine.end(), board, true );
board.saveSVG( "SimplePolygonalLine.svg" );
#ifdef WITH_CAIRO
board.saveCairo("SimplePolygonalLine.png", Board2D::CairoPNG);
#endif
board.clear();
drawPolygon( resGraham.begin(), resGraham.end(), board );
board.saveSVG( "SimplePolygonalLineGraham.svg" );
#ifdef WITH_CAIRO
board.saveCairo("SimplePolygonalLineGraham.png", Board2D::CairoPNG);
#endif
board.clear();
drawPolygon( res.begin(), res.end(), board );
board.saveSVG( "SimplePolygonalLineMelkman.svg" );
#ifdef WITH_CAIRO
board.saveCairo("SimplePolygonalLineMelkman.png", Board2D::CairoPNG);
#endif
board.clear();
drawPolygon( ch.begin(), ch.end(), board );
board.saveSVG( "SimplePolygonalLineMelkman2.svg" );
#ifdef WITH_CAIRO
board.saveCairo("SimplePolygonalLineMelkman2.png", Board2D::CairoPNG);
#endif
}
{ //order of the points for andrew algorithm
vector<Z2i::Point> res;
std::copy( pointSet.begin(), pointSet.end(), back_inserter( res ) );
std::sort( res.begin(), res.end() );
//display
Board2D board;
drawPolygon( res.begin(), res.end(), board, false );
board.saveSVG( "AndrewWEVP.svg" );
#ifdef WITH_CAIRO
board.saveCairo("AndrewWEVP.png", Board2D::CairoPNG);
#endif
}
{ //order of the points for graham algorithm
vector<Z2i::Point> res;
std::copy( pointSet.begin(), pointSet.end(), back_inserter( res ) );
//find an extremal point
//NB: we choose the point of greatest x-coordinate
//so that the sort step (by a polar comparator)
//returns a weakly externally visible polygon
std::vector<Z2i::Point>::iterator itMax
= std::max_element( res.begin(), res.end() );
//sort around this point with a polar comparator
functors::PolarPointComparatorBy2x2DetComputer<Z2i::Point> comparator;
comparator.setPole( *itMax );
std::sort( res.begin(), res.end(), comparator );
//display
Board2D board;
drawPolygon( res.begin(), res.end(), board, false );
board.saveSVG( "GrahamWEVP.svg" );
#ifdef WITH_CAIRO
board.saveCairo("GrahamWEVP.png", Board2D::CairoPNG);
#endif
}
}
