convexregionsD2< PT, PD > Class Template Reference

Construct regions by cutting specified regions with a 2D half spaces. More...

#include <convexregionsD2.h>

Collaboration diagram for convexregionsD2< PT, PD >:

List of all members.

Public Member Functions
	convexregionsD2 (vector< PT > &pts_)
	Pass in the global points.
boolc	split (uintc k, halfspaceD2< PT, PD > const &h)
	Split the region with the half space.
Public Attributes
vector< PT > &	pts
	List of points.
vector< polytopeD2linked >	vi
	Linked region that are convex.
Static Public Attributes
static bool	splittouchesface = false
	When split fails if the half space touches a line segment this flag is set.
static bool	splittouchespoint = false
	When split fails if the half space touches a one point this flag is set.
static uint	splittouchesindex = 0
	If the split touches this index is the first index position.

---

Detailed Description

template<typename PT, typename PD>
class convexregionsD2< PT, PD >

Construct regions by cutting specified regions with a 2D half spaces.

The region is assumed to be convex.

Definition at line 20 of file convexregionsD2.h.

---

Constructor & Destructor Documentation

template<typename PT , typename PD >

convexregionsD2< PT, PD >::convexregionsD2

(

vector< PT > &

pts_

)

[inline]

Pass in the global points.

Definition at line 58 of file convexregionsD2.h.

References convexregionsD2< PT, PD >::pts, and convexregionsD2< PT, PD >::vi.

  : pts(pts_) 
{
  vi.push_back( polytopeD2linked() );
  assert(pts.size()>0);
}

---

Member Function Documentation

template<typename PT , typename PD >

boolc convexregionsD2< PT, PD >::split	(	uintc	k,
		halfspaceD2< PT, PD > const &	h
	)			[inline]

Split the region with the half space.

Definition at line 68 of file convexregionsD2.h.

References partitionspace< PT >::classify().

{
  assert(k<vi.size());

  polytopeD2linked & x(vi[k]);

  uintc sz = x.pi.size();
  assert(sz>1);

  uint ci[sz];

  PT *beg = & x.pi[0]; 
  h.classify(ci,beg,beg+sz);

  // The two cutting positions
  uint cut[2];

  // Problem with templates so cut and paste the type.
  enum { undefined, below, on, above };

//  cut[0] = undefined;
//  cut[1] = undefined;

  uint index = 0;
  uint i2;

  for (uint i=0; i<sz; ++i)
  {
    if (ci[i]==on)
    {
      cut[index] = i;
      ++index;
      if (index==2)
        i=sz;
      continue;
    }

    i2 = (i+1)%sz;
    if (ci[i]==above)
    {
      if (ci[i2]==below)
      {
        cut[index] = i;
        ++index;
        if (index==2)
          i=sz;
        continue;
      } 
    }
  }

  // There should be two cuts.
  if (index==0)
    return false;

  if (index==1)
  {
    splittouchesface=false;
    splittouchespoint=true;
    splittouchesindex = cut[0];
    return false;
  }

  //uint a;
  uint status=0;
  if(cut[0]==on)
    status += 1;
  if(cut[1]==on)
    status += 2;

  switch (status)
  {
    // Two new points to be created.
    case 0:
      break;

    // First on, second to be made.
    case 1:
      break;

    // Second on, first to be made.
    case 2:
      break;

    // No new points to be created.
    case 3:
      // Handle line cutting face by rejection.
      if (cut[1] == (cut[0]+1)%sz)
      {
        splittouchesface = true;
        splittouchespoint = false;
        splittouchesindex = cut[0];
        return false;
      }
      if (cut[0] == (cut[1]+1)%sz)
      {
        splittouchesface = true;
        splittouchespoint = false;
        splittouchesindex = cut[1];
        return false;
      }
      break;
  }


  return true;
}

---

Member Data Documentation

template<typename PT , typename PD >

vector< PT >& convexregionsD2< PT, PD >::pts

List of points.

Definition at line 25 of file convexregionsD2.h.

Referenced by convexregionsD2< PT, PD >::convexregionsD2().

template<typename PT , typename PD >

bool convexregionsD2< PT, PD >::splittouchesface = false [inline, static]

When split fails if the half space touches a line segment this flag is set.

Definition at line 37 of file convexregionsD2.h.

template<typename PT , typename PD >

uint convexregionsD2< PT, PD >::splittouchesindex = 0 [inline, static]

If the split touches this index is the first index position.

Definition at line 43 of file convexregionsD2.h.

template<typename PT , typename PD >

bool convexregionsD2< PT, PD >::splittouchespoint = false [inline, static]

When split fails if the half space touches a one point this flag is set.

Definition at line 40 of file convexregionsD2.h.

template<typename PT , typename PD >

vector< polytopeD2linked > convexregionsD2< PT, PD >::vi

Linked region that are convex.

Definition at line 27 of file convexregionsD2.h.

Referenced by convexregionsD2< PT, PD >::convexregionsD2().

---

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

• compgeomlib/convexregionsD2.h