boxcollision Class Reference

Define a primitive Axis aligned bounding box. More...

#include <boxcollision.h>

Collaboration diagram for boxcollision:

List of all members.

Public Member Functions
	boxcollision (doublec x0_, doublec x1_, doublec y0_, doublec y1_)
	Construct rectangular region.
boolc	left (particle &p, doublec h) const
	Test for collision with the left wall, if there is a collision then resolve the collision.
boolc	right (particle &p, doublec h) const
	Test for collision with the right wall, if there is a collision then resolve the collision.
boolc	up (particle &p, doublec h) const
	Test for collision with the top wall, if there is a collision then resolve the collision.
boolc	down (particle &p, doublec h) const
	Test for collision with the below wall, if there is a collision then resolve the collision.
boolc	walls (particle &p, doublec h) const
	Resolve any collision the particle has with the walls.
ostream &	print (ostream &os) const
	Print the bounding box.
Public Attributes
double	x0
	The left wall.
double	x1
	The right wall.
double	y0
	The below wall.
double	y1
	The above wall.

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Detailed Description

Define a primitive Axis aligned bounding box.

The particles are assumed to be inside the box. If a collision is detected, the particle's path is reversed and the particle is bounced off the wall. Assuming that the particles previous initial position was valid.

Definition at line 18 of file boxcollision.h.

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Constructor & Destructor Documentation

boxcollision::boxcollision	(	doublec	x0_,
		doublec	x1_,
		doublec	y0_,
		doublec	y1_
	)			[inline]

Construct rectangular region.

Definition at line 34 of file boxcollision.h.

    : x0(x0_), x1(x1_), y0(y0_), y1(y1_) {}

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Member Function Documentation

boolc boxcollision::down	(	particle &	p,
		doublec	h
	)			const

Test for collision with the below wall, if there is a collision then resolve the collision.

Definition at line 83 of file boxcollision.cpp.

References particle::pos, particle::radius, SHOW, particle::step(), particle::vel, and y0.

Referenced by walls().

{
  assert(h>0.0);

  if ( y0+p.radius < p.pos[1] )
    return false;

  p.step(-h);

  assert(p.vel[1]!=0.0);
  doublec t1 = 
    (y0+p.radius-p.pos[1])/p.vel[1];
  doublec t2 = h-t1;

#ifdef DEGUG_BOX
if ((t1>0.0)==false)
{
  cout << SHOW(t1) << " " << SHOW(t2) << " " << SHOW(h) << endl;
}
#endif

  p.step(t1-h);

  p.vel[1]*=-1.0;
  p.step(t2);

  return true;
}

boolc boxcollision::left	(	particle &	p,
		doublec	h
	)			const

Test for collision with the left wall, if there is a collision then resolve the collision.

Definition at line 17 of file boxcollision.cpp.

References particle::pos, particle::radius, particle::step(), particle::vel, and x0.

Referenced by walls().

{
  assert(h>0.0);

  if ( x0 < p.pos[0]-p.radius )
    return false;

  p.step(-h);

  assert(p.vel[0]!=0.0);
  doublec t1 = 
    (x0+p.radius-p.pos[0])/p.vel[0];
  doublec t2 = h-t1;

  p.step(t1-h);

  p.vel[0]*=-1.0;
  p.step(t2);

  return true;
}

ostream& boxcollision::print

(

ostream &

os

)

const [inline]

Print the bounding box.

Definition at line 71 of file boxcollision.h.

References x0, x1, y0, and y1.

    { os << "x0=" << x0 << " x1=" << x1;
      return os << " y0=" << y0 << " y1=" << y1; }

boolc boxcollision::right	(	particle &	p,
		doublec	h
	)			const

Test for collision with the right wall, if there is a collision then resolve the collision.

Definition at line 39 of file boxcollision.cpp.

References particle::pos, particle::radius, particle::step(), particle::vel, and x1.

Referenced by walls().

{
  assert(h>0.0);

  if ( p.pos[0] < x1-p.radius )
    return false;

  p.step(-h);

  assert(p.vel[0]!=0.0);
  doublec t1 = 
    (x1-p.radius-p.pos[0])/p.vel[0];
  doublec t2 = h-t1;

  p.step(t1-h);

  p.vel[0]*=-1.0;
  p.step(t2);

  return true;
}

boolc boxcollision::up	(	particle &	p,
		doublec	h
	)			const

Test for collision with the top wall, if there is a collision then resolve the collision.

Definition at line 61 of file boxcollision.cpp.

References particle::pos, particle::radius, particle::step(), particle::vel, and y1.

Referenced by walls().

{
  assert(h>0.0);

  if ( p.pos[1] < y1-p.radius )
    return false;

  p.step(-h);

  assert(p.vel[1]!=0.0);
  doublec t1 = 
    (y1-p.radius-p.pos[1])/p.vel[1];
  doublec t2 = h-t1;

  p.step(t1-h);

  p.vel[1]*=-1.0;
  p.step(t2);

  return true;
}

boolc boxcollision::walls	(	particle &	p,
		doublec	h
	)			const [inline]

Resolve any collision the particle has with the walls.

Definition at line 56 of file boxcollision.h.

References down(), left(), right(), and up().

Referenced by integration< D, F >::bruteforce(), and integration< D, F >::uniformgridtest().

  {
    if (left(p,h))
      return true;
    if (right(p,h))
      return true;
    if (up(p,h))
      return true;
    if (down(p,h))
      return true;

    return false;
  }

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Member Data Documentation

double boxcollision::x0

The left wall.

Definition at line 24 of file boxcollision.h.

Referenced by particlev0spaced::eval(), d2toindex::index(), left(), print(), particledistribution::randomposition(), and d2toindex::reset().

double boxcollision::x1

The right wall.

Definition at line 26 of file boxcollision.h.

Referenced by particlev0spaced::eval(), print(), particledistribution::randomposition(), d2toindex::reset(), and right().

double boxcollision::y0

The below wall.

Definition at line 28 of file boxcollision.h.

Referenced by down(), particlev0spaced::eval(), d2toindex::index(), print(), particledistribution::randomposition(), and d2toindex::reset().

double boxcollision::y1

The above wall.

Definition at line 30 of file boxcollision.h.

Referenced by particlev0spaced::eval(), print(), particledistribution::randomposition(), d2toindex::reset(), and up().

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

• nbody/boxcollision.h
• nbody/boxcollision.cpp