polytrimon Class Reference

Linear time triangulation of monotone polygons. More...

#include <polytrimon.h>

Collaboration diagram for polytrimon:

List of all members.

Public Member Functions
	polytrimon (vector< point2< float > > const &pts_)
	Pass in the points of monotone polygon ordered clockwise from the highest point.
template<typename T >
void	tessellate (T f)
void	vsprint () const
void	colorsprint () const
void	vyprint () const
Public Attributes
vector< point2< float > > const &	pts
	Polyline of 2D points.
vector< uint >	colors
	Each point is either on the rhs (black)=1, the left hand side (white)=2 or both=1+2=3 eg the start and finish points.
vector< uint >	vy
	pts[] ordered on the y-axis in constructor.
deque< uint >	vs
	The current tessellation state.

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Detailed Description

Linear time triangulation of monotone polygons.

Assume that the order of the points is clockwise starting from the top.

Definition at line 20 of file polytrimon.h.

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Constructor & Destructor Documentation

polytrimon::polytrimon

(

vector< point2< float > > const &

pts_

)

Pass in the points of monotone polygon ordered clockwise from the highest point.

Definition at line 83 of file polytrimon.cpp.

References pts.

  : pts(pts_)
{
  assert(pts.size()>2);
   
  colorsinit();

  vyinit();
}

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Member Function Documentation

void polytrimon::colorsprint

(

)

const

Definition at line 19 of file polytrimon.cpp.

References colors.

{
  cout << "colors: ";
  for (uint i=0; i<colors.size(); ++i)
    cout << i << "=" << colors[i] << " ";
  cout << endl;
}

template<typename T >

void polytrimon::tessellate

(

T

f

)

[inline]

Definition at line 64 of file polytrimon.h.

References colors, vs, and vy.

Referenced by test01(), and test02().

{
  vs.push_front( vy[0] );
  vs.push_front( vy[1] );

  uint imax= vy.size();

  // The first two points from the current vs state. 
  uint z0;
  uint z1;

  for (uint i=2; i<imax; ++i)
  {
    vs.push_front( vy[i] );
//vsprint();

    z0 = vs[0];
    z1 = vs[1];

    bool samecolor = 
      (( colors[ z0 ] & colors[ z1 ])!=0);

    if (samecolor==false)
    {
      // Triangle fan about z0.
      for (uint k=2; k<vs.size(); ++k)
        f(z0,vs[k-1],vs[k]);

      vs.clear();
      vs.push_front(z1);
      vs.push_front(z0);
    }
    else
    {
      for ( ; ispointvisible(); )
      {
        z0 = vs[0];
        z1 = vs[1];

        f(z0,z1,vs[2]);

        vs.pop_front();
        vs.pop_front();
        vs.push_front(z0);
      }
    }
  } 
}

void polytrimon::vsprint

(

)

const

Definition at line 11 of file polytrimon.cpp.

References vs.

{
  cout << "vs: ";
  for (uint i=0; i<vs.size(); ++i)
    cout << vs[i] << " ";
  cout << endl;
}

void polytrimon::vyprint

(

)

const

Definition at line 27 of file polytrimon.cpp.

References vy.

{
  cout << "vy: ";
  for (uint i=0; i<vy.size(); ++i)
    cout << vy[i] << " ";
  cout << endl;
}

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Member Data Documentation

vector< uint > polytrimon::colors

Each point is either on the rhs (black)=1, the left hand side (white)=2 or both=1+2=3 eg the start and finish points.

Definition at line 38 of file polytrimon.h.

Referenced by colorsprint(), and tessellate().

vector< point2<float> > const& polytrimon::pts

Polyline of 2D points.

Definition at line 33 of file polytrimon.h.

deque<uint> polytrimon::vs

The current tessellation state.

Definition at line 48 of file polytrimon.h.

Referenced by tessellate(), and vsprint().

vector< uint > polytrimon::vy

pts[] ordered on the y-axis in constructor.

Definition at line 41 of file polytrimon.h.

Referenced by tessellate(), and vyprint().

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The documentation for this class was generated from the following files:

• polytrimon/polytrimon.h
• polytrimon/polytrimon.cpp