d3meshpartition Class Reference

Brute force (quadratic) general mesh subtraction. More...

#include <d3meshpartition.h>

Inheritance diagram for d3meshpartition:

Collaboration diagram for d3meshpartition:

List of all members.

Public Member Functions
	d3meshpartition (d3tess &meshB_)
bool const	isInside (pt3c &x) const
bool const	intersection (pt3 &x, pt3c &w, pt3c &b) const
bool const	isOnBoundary (pt3c &w, double const zero) const
	The boundary is interpreted as a simplex face having no neighbor.
Public Attributes
d3tess &	meshB

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Detailed Description

Brute force (quadratic) general mesh subtraction.

All the meshes simplexes are transversed for isInside and intersection. This becomes expensive as if there are m simplexes in mesh A and n simplexes in mesh B then A - B is O(m)O(n).

The method is robust and easy to implement.

Definition at line 22 of file d3meshpartition.h.

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Constructor & Destructor Documentation

d3meshpartition::d3meshpartition

(

d3tess &

meshB_

)

[inline]

Definition at line 28 of file d3meshpartition.h.

    : meshB(meshB_) {}

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Member Function Documentation

bool const d3meshpartition::intersection	(	pt3 &	x,
		pt3c &	w,
		pt3c &	b
	)			const

Definition at line 34 of file d3meshpartition.cpp.

References lineintersection(), meshB, d3tess::pt, and d3tess::vi.

{

  vector<d3tri> const & vi(meshB.vi);
  vector<pt3> const & pt(meshB.pt);

  static vector<pt3> solutions;
  solutions.clear();

  double t0,t1;

  uintc sz = vi.size();
  uint k;
  for (uint i=1; i<sz; ++i)
  {
    d3tri const & y(vi[i]);

    if (y.isonboundary()==false)
      continue;

    for (k=0; k<3; ++k)
    {
      if (y.ni[k]!=0)
        continue;

      pt3c & c(pt[ y.pi[(k+1)%3] ]);
      pt3c & d(pt[ y.pi[(k+2)%3] ]);
      if (lineintersection(t0,t1,w,b,c,d))
      {
        if ((t1>=0.0)&&(t1<=1.0))
          solutions.push_back(c+(d-c)*t1);
      }
    }
  }

  assert(solutions.empty()==false);

  uintc solsz = solutions.size();
  if (solsz==1)
  {
    x = solutions[0];
    return true;
  }

  uint di = 0;
  double dmin = (w-solutions[0]).dot();
  double d;
 
  for (uint i=1; i<solsz; ++i)
  {
    d = (w-solutions[i]).dot();
    if (d<dmin)
    {
      dmin = d;
      di = i;
    }
  }

  x = solutions[di];
  return true;
}

bool const d3meshpartition::isInside

(

pt3c &

x

)

const

Definition at line 9 of file d3meshpartition.cpp.

References trianglespace< T, D >::isInside(), meshB, d3tess::pt, and d3tess::vi.

{
  vector<d3tri> const & vi(meshB.vi);
  vector<pt3> const & pt(meshB.pt);
  uintc sz = vi.size();
  for (uint i=1; i<sz; ++i)
  {
    d3tri const & y(vi[i]);
     
    trianglespace< pt3, double > t
    ( 
      pt[ y.pi[0] ],
      pt[ y.pi[1] ],
      pt[ y.pi[2] ]
    );

    if (!t.isInside(x))
      return true;
  }

  return false;
}

bool const d3meshpartition::isOnBoundary	(	pt3c &	w,
		double const	zero
	)			const

The boundary is interpreted as a simplex face having no neighbor.

Definition at line 96 of file d3meshpartition.cpp.

References trianglespace< T, D >::isOnBoundary(), meshB, d3tess::pt, and d3tess::vi.

{
  // Find the simplex with the point w.

  vector<d3tri> const & vi(meshB.vi);
  vector<pt3> const & pt(meshB.pt);
  uintc sz = vi.size();
  for (uint i=1; i<sz; ++i)
  {
    d3tri const & y(vi[i]);
     
    // Inefficent code. Just get working, optimize later.
    trianglespace< pt3, double > t
    ( 
      pt[ y.pi[0] ],
      pt[ y.pi[1] ],
      pt[ y.pi[2] ]
    );

//    if (!t.isInside(w))
    if (t.isOnBoundary(w,zero))
      return true;
  }

  return false;
}

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Member Data Documentation

d3tess& d3meshpartition::meshB

Definition at line 26 of file d3meshpartition.h.

Referenced by d3meshpartitiondraw::d3meshpartitiondraw(), intersection(), isInside(), and isOnBoundary().

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

• clipping/d3meshpartition.h
• clipping/d3meshpartition.cpp