Mercator
Public Member Functions | Private Attributes
Mercator::Edge Class Reference

The edge of an area. More...

List of all members.

Public Member Functions

 Edge (const Point2 &a, const Point2 &b)
 Constructor.
Point2 start () const
 Accessor for the point describing the start of the edge.
Point2 end () const
 Determine the point describing the end of the edge.
double xValueAtY (double y) const
 Determine the x coordinate at a given y coordinate.
bool operator< (const Edge &other) const
 Compare the y coordinate of the start with another edge.

Private Attributes

Point2 m_start
 The point describing the start of the edge.
Vector2 m_seg
 The vector describing the edge from its start.
double m_inverseGradient
 The inverse of the gradient of the line.

Detailed Description

The edge of an area.


Constructor & Destructor Documentation

Mercator::Edge::Edge ( const Point2 &  a,
const Point2 &  b 
) [inline]

Constructor.

Parameters:
aone end of the line defining the edge.
bone end of the line defining the edge.

References m_inverseGradient, m_seg, and m_start.


Member Function Documentation

bool Mercator::Edge::operator< ( const Edge other) const [inline]

Compare the y coordinate of the start with another edge.

This operator ensures that edges can be sorted, compares the y y coordinate of the start of the edges.

References m_start.

double Mercator::Edge::xValueAtY ( double  y) const [inline]

Determine the x coordinate at a given y coordinate.

Calculate the x coordinate on the edge line where the y coordinate is the value specified.

Parameters:
ythe y coordinate where the calculation is required.

References m_inverseGradient, and m_start.

Referenced by Mercator::EdgeAtY::operator()().


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