Path Class Reference

Three dimensional path in space. More...

#include <Simulation/path.h>

Inheritance diagram for Path:

List of all members.

Public Types
enum	Error {   INIT_ERROR, RESULT_PAST_PATH, RESULT_BEHIND_PATH, NOT_ON_PATH,   PROTECTION_FAULT, INVALID_COORD }
	Special Path Errors. More...
Public Member Functions
void	Step (Point &in_pt, const double delta) const
	Step displaces in_pt delta distance along the path.
virtual void	Jump (Point &in_pt, const double dist) const
	Jump displaces in_pt to a point on the path that is delta distance away in 3 space.
void	Reduce (const double dist, LineContext *lc_array)
	Optimize the SAMPLE representation of the path.
virtual void	Splice (const double begin, const double end)
	Clip path to subsection as per length coordinates.
virtual double	Length (void) const
	the length of the path
virtual double	Curvature (void) const
	measure of path's curvature; integration of the 2nd derivative
virtual LineContext *	ClosestDistance (LineContext *lc_array) const
	find the distance to the obstacle closest to the path
virtual Intersection	Collide (const double radius, LineContext *lc_array) const
	see if any obstacle is within a certain distance of the path
virtual double	GetDistance (const Path &path, Point &ret1, Point &ret2) const
	determine the closest distance between two paths
void	SetProtectedLength (const double len)
	protect the path range [0..len] from any mutations
virtual Point	ProjectPoint (const Vector &p) const
	find point on path closest to p
virtual Point	GetPoint (const Vector &p) const
	retrieve point on path
virtual Point	GetPoint (const double d) const
	retrieve point on path
Point	operator[] (const double s) const
	retrieve point on path
Point	operator[] (const Vector &v) const
	retrieve point on path
virtual Vector	Tangent (const Point &p) const
	retrieve tangent of a path point given 3D position
virtual Vector	Tangent (const double d) const
	retrieve tangent of a path point given path coordinate
void	AddSample (const Vector &pos)
	append a sample to the path; note that this connects pos to the current end of the path
Path &	operator+= (const Vector &v)
	operator version of AddSample
Path &	operator+= (const Path &app)
	much like AddSample, but adds an entire path at once
Path	operator+ (const Path &app) const
	much like AddSample, but adds an entire path at once
virtual Path	Subsection (const double begin, const double end) const
	similar to Splice, except does not modify parent path
void	Render (const double color[]) const
	draw the path's samples with the desired color (RGBA)
void	Render (void) const
	render the path's samples with the path's default color
virtual ConStruct	ToConstruct () const
	archives the path in a ConStruct and outputs to a file
void	SetColor (const Vector &color, double opacity)
	set the path's color
virtual Path	Clone (void) const
	Explicitly copy data to new Path, instead of just getting a reference.
	Path ()
	constructs empty path
	Path (const Path &path)
	copy constructor
	Path (const ConStruct &con)
	constructs path from ConStruct data
virtual	~Path ()
	destructor
Static Public Member Functions
static Path	Combine (const Path &p1, const Path &p2)
	appends the list of SAMPLES in p2 to the SAMPLES in p1
Static Public Attributes
static const double	BEGIN = 0.
	specifies the beginning of the path in path coordinates
static const double	END = -1.
	specifies the end of the path in path coordinates
Protected Attributes
double	fixed_length
	prevents mutation of path from [0..fixed_length]
Samples *	samples
	pointer to the path's data
Classes
class	Point
	an estimate of a sample on a path More...
struct	Samples
	all relevant path data; in a struct to make reference counting easier More...

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Detailed Description

Three dimensional path in space.

Note:

The Path class AND its descendents are one dimensional manifolds in three space. Since paths have many different representations (implicit, spline, nonanalytical) all this class does is store SAMPLEs of the points along the true path. The class also maintains a path length coordinate for each SAMPLE. Linear interpolation is used to work with points between samples. Descendant classes can override members to use more appropriate interpolation.

As is typical in numerical computing, keep in mind that SAMPLEs and especially their corresponding path coordinate should be considered as estimates, not 100% accurate values.

For descendents of Path, the POINT ACQUISITION functions *should* guarantee that they will return an accurate estimate on the path. In the case of Path, it returns an interpolated point.

Path will throw two kinds of exceptions: regular Construct Errors and special Path Errors.

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Member Enumeration Documentation

enum Path::Error

Special Path Errors. Enumerator: INIT_ERROR  problem initializing the path RESULT_PAST_PATH  an operation (such as a Step) produced a result that would have a path length coordinate greater than the path length RESULT_BEHIND_PATH  similar to the RESULT_PAST_PATH, except coordinate would be < 0 NOT_ON_PATH  input provided did not result in a point on the path PROTECTION_FAULT  attempted to modify a part of the path that was set as "immutable" INVALID_COORD  invalid path coordinate was used

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Member Function Documentation

void Path::AddSample (  const Vector &  pos  )

append a sample to the path; note that this connects pos to the current end of the path Parameters: pos  desired point to append

Path Path::Clone (  void   )  const [virtual]

Explicitly copy data to new Path, instead of just getting a reference. Returns: copy of the path

LineContext * Path::ClosestDistance (  LineContext *  lc_array  )  const [virtual]

find the distance to the obstacle closest to the path Parameters: lc_array  LineContext for carrying out distance calculations Returns: description of distance result

Intersection Path::Collide (  const double  radius, LineContext *  lc_array )  const [virtual]

see if any obstacle is within a certain distance of the path Parameters: radius  threshold distance from the path lc_array  LineContext for carrying out distance calculations Returns: structure describing Intersection

Path Path::Combine (  const Path &  p1, const Path &  p2 )  [static]

appends the list of SAMPLES in p2 to the SAMPLES in p1 Note: generates a new Path with the combination as its SAMPLE list please note that the resulting type is Path, so any specific parameterizations in p1 and p2 are lost in the resulting type

double Path::GetDistance (  const Path &  path, Point &  ret1, Point &  ret2 )  const [virtual]

determine the closest distance between two paths Parameters: path  other path from which to determine distance ret1  return value of closest point to path on this ret2  return value of closest point to this on path Returns: magnitude of distance

Path::Point Path::GetPoint (  const double  d  )  const [virtual]

retrieve point on path Parameters: d  desired path coordinate Returns: point on the path

Path::Point Path::GetPoint (  const Vector &  p  )  const [virtual]

retrieve point on path Note: TODO: write this note... Parameters: p  3D position of desired point Returns: point on the path

void Path::Jump (  Point &  in_pt, const double  dist )  const [virtual]

Jump displaces in_pt to a point on the path that is delta distance away in 3 space. Note: One way to consider jumping is to consider intersecting a sphere centered at in_pt with delta radius with the Path. Call the set of intersected points P. Jump will displace in_pt to the element in P whose length coordinate is the least greater than in_pt's.

Path Path::operator+ (  const Path &  app  )  const

much like AddSample, but adds an entire path at once Parameters: app  desired path to append

Path & Path::operator+= (  const Path &  app  )

much like AddSample, but adds an entire path at once Parameters: app  desired path to append

Path & Path::operator+= (  const Vector &  v  )

operator version of AddSample Parameters: v  desired point to append

Path::Point Path::operator[] (  const Vector &  v  )  const

retrieve point on path Parameters: v  3D position of desired point Returns: point on the path

Path::Point Path::operator[] (  const double  s  )  const

retrieve point on path Parameters: s  desired path coordinate Returns: point on the path

Path::Point Path::ProjectPoint (  const Vector &  p  )  const [virtual]

find point on path closest to p Parameters: p  point to project onto this Returns: projected point

void Path::Reduce (  const double  dist, LineContext *  lc_array )

Optimize the SAMPLE representation of the path. Note: Reduce eliminates SAMPLEs while maintaining the overall shape of the path

void Path::Render (  const double  color[]  )  const

draw the path's samples with the desired color (RGBA) Parameters: color  color with which to render

void Path::SetColor (  const Vector &  color, double  opacity )

set the path's color Parameters: color  desired color coordinates opacity  how opaque the path is, 0 is clear, 1 is solid

void Path::SetProtectedLength (  const double  len  )

protect the path range [0..len] from any mutations Parameters: len  the upper range coordinate to protect

void Path::Splice (  const double  begin, const double  end )  [virtual]

Clip path to subsection as per length coordinates. Note: if s1 > s2, then the sequence of points is reversed

void Path::Step (  Point &  in_pt, const double  delta )  const

Step displaces in_pt delta distance along the path. Parameters: in_pt  the position from which to step delta  the magnitude of the step

Path Path::Subsection (  const double  begin, const double  end )  const [virtual]

similar to Splice, except does not modify parent path Parameters: begin  the path coordinate defining the beginning of the new path end  the path coordinate definiing the end of the new path

Vector Path::Tangent (  const double  d  )  const [virtual]

retrieve tangent of a path point given path coordinate Parameters: d  path coordinate at which to measure tangent Returns: tangent vector facing in the direction of increasing path coordinate

Vector Path::Tangent (  const Point &  p  )  const [virtual]

retrieve tangent of a path point given 3D position Parameters: p  point at which to measure tangent Returns: tangent vector facing in the direction of increasing path coordinate

ConStruct Path::ToConstruct (   )  const [virtual]

archives the path in a ConStruct and outputs to a file Returns: ConStruct representation of the path

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

• /home/snake/Construct/include/Simulation/path.h
• /home/snake/Construct/src/Simulation/path.cpp

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