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DLine2 Class Reference
Inheritance diagram for DLine2:
Inheritance graph
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Public Member Functions

 DLine2 (int size)
 
 DLine2 (const DLine2 &ref)
 
DLine2operator= (const DLine2 &v)
 
DLine2operator= (const FLine2 &v)
 
void Add (const DPoint2 &p)
 Add a given offset to all points.
 
void Mult (double factor)
 Multiply all points by a given factor.
 
void InsertPointAfter (int iInsertAfter, const DPoint2 &Point)
 
void RemovePoint (int i)
 
void ReverseOrder ()
 
int RemoveDegeneratePoints (double dEpsilon, bool bClosed)
 
int RemoveColinearPoints (double dEpsilon, bool bClosed)
 
bool ContainsPoint (const DPoint2 &p) const
 
double SegmentLength (uint i) const
 
void NearestPoint (const DPoint2 &Point, int &iIndex, double &dist) const
 
bool NearestSegment (const DPoint2 &Point, int &iIndex, double &dist, DPoint2 &Intersection) const
 
bool IsConvex () const
 
DPoint2GetSafePoint (int index) const
 
void SetSafePoint (int index, const DPoint2 &p)
 
double Length () const
 
DPoint2 Centroid () const
 
DPoint2 Centroid2 () const
 
double Area () const
 
- Public Member Functions inherited from vtArray< DPoint2 >
 vtArray (uint size=0)
 
 vtArray (const vtArray< DPoint2 > &)
 
uint GetSize () const
 
uint GetMaxSize () const
 
bool SetSize (uint)
 
bool SetMaxSize (uint)
 
uint GetElemSize () const
 
DPoint2GetData () const
 
void FreeData ()
 
bool IsEmpty () const
 
DPoint2GetAt (uint i) const
 
bool SetAt (uint i, DPoint2)
 
vtArray< DPoint2 > & operator= (const vtArray< DPoint2 > &)
 
DPoint2operator[] (uint i)
 
const DPoint2operator[] (uint i) const
 
void Clear ()
 
bool RemoveAt (uint i, int n=1)
 
int Append (const DPoint2 &)
 
int Append (const vtArray< DPoint2 > &)
 
int Find (const DPoint2 &) const
 

Additional Inherited Members

- Protected Member Functions inherited from vtArray< DPoint2 >
virtual bool Grow (uint)
 
virtual void DestructItems (uint first, uint last)
 
- Protected Attributes inherited from vtArray< DPoint2 >
uint m_Size
 
uint m_MaxSize
 
DPoint2m_Data
 

Detailed Description

A series of 2D points. This is useful for representing either a series of points, line segments or a simple closed polygon. Double-precision.

Member Function Documentation

DPoint2 DLine2::Centroid ( ) const

Centroid (centre of gravity/mass) of the polygon

Note: I've observed some numerical precision issues with this method. With 7-digit coordinates (e.g. x=2388836, y=4690396) the centroid computed may be several units away from its correct location, in fact even outside the polygon for a convex shape.

DPoint2 DLine2::Centroid2 ( ) const

(Approximate) centroid of a polygon, using simple averaging of the vertices.

bool DLine2::ContainsPoint ( const DPoint2 p) const

With the assumption that this set of points defines a closed polygon, test whether the polygon contains a given point. Since a simple array of points being interpreted as a polygon, this means the data may be concave or convex, but not contains holes.

DPoint2 & DLine2::GetSafePoint ( int  index) const

Get a point on the line, safely wrapping around to the end or beginning for index values that are out of range.

void DLine2::NearestPoint ( const DPoint2 Point,
int &  iIndex,
double &  dClosest 
) const

Return the nearest point (of the points which make up the line). This is not the same as the closest place on the line, which may lie between the defining points; use NearestSegment to find that.

Parameters
PointThe input point.
iIndexIndex of the first point of the nearest line segment.
dClosestDistance from the DLine2 to the input point.
bool DLine2::NearestSegment ( const DPoint2 Point,
int &  iIndex,
double &  dist,
DPoint2 Intersection 
) const

Returns the location of the closest point on the line to a given point.

Parameters
PointThe input point.
iIndexIndex of the first point of the nearest line segment.
distDistance from the DLine2 to the input point.
IntersectionThe closest point on the DLine2.
Returns
True if a closest point was found.
int DLine2::RemoveColinearPoints ( double  dEpsilon,
bool  bClosed 
)

Given three points A B C, where the distance from B to the line A-C is less than dEpsilon units, B is co-linear and should be removed.

We could use another measure of linearity, the angle between (B-A) and (C-A), but didn't do that.

Parameters
dEpsilonDistance.
bClosedIf true, treat this as a closed polyline (a simple polygon) by wrapping around from the last to the first point.
int DLine2::RemoveDegeneratePoints ( double  dEpsilon,
bool  bClosed 
)

Given four points A B C D, where B and C are identical, then this line is a triangle not a rectangle. Remove the identical points to produce A B D. Points are identical if they are within dEpsilon of each other.

Parameters
dEpsilonDistance.
bClosedIf true, treat this as a closed polyline (a simple polygon) by wrapping around from the last to the first point.
double DLine2::SegmentLength ( uint  i) const

Return the length of the N'th segment in the line, which is the distance between points N and N+1. If the length of the last segment is requested, a closed polygon is assumed.