d3clipping Class Reference

2D simplex mesh subtraction. More...

#include <d3clipping.h>

Collaboration diagram for d3clipping:

List of all members.

Public Member Functions
	d3clipping (d3tess &tess_, partitionspace< pt3, double > const &H_)
	Clip the tessellation against the line.
void	eval ()
	Clip the tessellation against the partition.
Public Attributes
vector< bool >	bv
	Short for black value it is true if the associated point is black in color.
double	zero
	Client configures zero for isOnBoundary routine.

---

Detailed Description

2D simplex mesh subtraction.

The partition is used to find the intersection between the mesh and itself. It then clips the mesh. So the partition is subtracted from the mesh.

The algorithm works by classifying points as either white or black. Points with all white points are discarded and points with all black points are accepted.

Triangles with white and black points are reclassified as a black point on the boundary is different from a black point not one the boundary. For example two white points and one black on the boundary is discarded as it is equivalent to three white points.

Example

#include <point.h>
#include <d3tess.h>
#include <d3clipping.h>
...
<TODO>

Definition at line 38 of file d3clipping.h.

---

Constructor & Destructor Documentation

d3clipping::d3clipping	(	d3tess &	tess_,
		partitionspace< pt3, double > const &	H_
	)

Clip the tessellation against the line.

Definition at line 46 of file d3clipping.cpp.

  : tess(tess_), vi(tess.vi), pt(tess.pt), H(H_)
{
}

---

Member Function Documentation

void d3clipping::eval

(

)

Clip the tessellation against the partition.

Definition at line 243 of file d3clipping.cpp.

References bv, and partitionspace< PT >::isInside().

{
  uint ptsz = pt.size();
  bv.resize(ptsz);
  // Ignore the first element as point 0 is defined as no point.
  bv[0]=true;
  // Because the partition H is subtracting from the mesh its
  // balls are white.  So the H.isInside function has to be
  // inverted.  If the point is on H's boundary there is a possibiliby
  // that it could be classified wrongly.  In this case I believe
  // the algorithm is robust enough to handle it by re interpreting any
  // 2 black 1 white cases to 3 black again because such cases are 
  // re processed anyway.
  for (uint i=1; i<ptsz; ++i)
    bv[i] = ! H.isInside( pt[i] );

  for (uint i=1; i<vi.size(); ++i )
    processSimplex(i);
}

---

Member Data Documentation

vector<bool> d3clipping::bv

Short for black value it is true if the associated point is black in color.

Definition at line 85 of file d3clipping.h.

Referenced by eval().

double d3clipping::zero

Client configures zero for isOnBoundary routine.

eg zero = 1.0e-10

Definition at line 99 of file d3clipping.h.

Referenced by test01obj< P, PD >::test01obj().

---

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

• clipping/d3clipping.h
• clipping/d3clipping.cpp