TriangleBoundary Class Reference

#include "AreaBoundary.h"

Inheritance diagram for TriangleBoundary:

Public Member Functions
	TriangleBoundary (Position const &pointA, Position const &pointB, Position const &pointC, bool isInverted=false)
Public Member Functions inherited from AreaBoundary
bool	IsWithinBoundary (Position const *pos) const
bool	IsWithinBoundary (Position const &pos) const
virtual	~AreaBoundary ()

Protected Member Functions
bool	IsWithinBoundaryArea (Position const *pos) const override
Protected Member Functions inherited from AreaBoundary
	AreaBoundary (bool isInverted)
virtual bool	IsWithinBoundaryArea (Position const *pos) const =0

Private Attributes
DoublePosition const	_a
DoublePosition const	_b
DoublePosition const	_c
double const	_abx
double const	_bcx
double const	_cax
double const	_aby
double const	_bcy
double const	_cay

Detailed Description

Constructor & Destructor Documentation

TriangleBoundary()

TriangleBoundary::TriangleBoundary	(	Position const &	pointA,
		Position const &	pointB,
		Position const &	pointC,
		bool	isInverted = false
	)

                                                                                                                          :
    AreaBoundary(isInverted), _a(pointA), _b(pointB), _c(pointC), _abx(_b.GetDoublePositionX()-_a.GetDoublePositionX()), _bcx(_c.GetDoublePositionX()-_b.GetDoublePositionX()), _cax(_a.GetDoublePositionX() - _c.GetDoublePositionX()), _aby(_b.GetDoublePositionY()-_a.GetDoublePositionY()), _bcy(_c.GetDoublePositionY()-_b.GetDoublePositionY()), _cay(_a.GetDoublePositionY() - _c.GetDoublePositionY()) { }

Member Function Documentation

IsWithinBoundaryArea()

bool TriangleBoundary::IsWithinBoundaryArea ( Position const *  pos ) const

overrideprotectedvirtual

Implements AreaBoundary.

{
    // half-plane signs
    bool sign1 = ((-_b.GetDoublePositionX() + pos->GetPositionX()) * _aby - (-_b.GetDoublePositionY() + pos->GetPositionY()) * _abx) < 0;
    bool sign2 = ((-_c.GetDoublePositionX() + pos->GetPositionX()) * _bcy - (-_c.GetDoublePositionY() + pos->GetPositionY()) * _bcx) < 0;
    bool sign3 = ((-_a.GetDoublePositionX() + pos->GetPositionX()) * _cay - (-_a.GetDoublePositionY() + pos->GetPositionY()) * _cax) < 0;
 
    // if all signs are the same, the point is inside the triangle
    return ((sign1 == sign2) && (sign2 == sign3));
}

References _a, _abx, _aby, _b, _bcx, _bcy, _c, _cax, _cay, AreaBoundary::DoublePosition::GetDoublePositionX(), AreaBoundary::DoublePosition::GetDoublePositionY(), Position::GetPositionX(), and Position::GetPositionY().

Member Data Documentation

_a

DoublePosition const TriangleBoundary::_a

private

Referenced by IsWithinBoundaryArea().

_abx

double const TriangleBoundary::_abx

private

Referenced by IsWithinBoundaryArea().

_aby

double const TriangleBoundary::_aby

private

Referenced by IsWithinBoundaryArea().

_b

DoublePosition const TriangleBoundary::_b

private

Referenced by IsWithinBoundaryArea().

_bcx

double const TriangleBoundary::_bcx

private

Referenced by IsWithinBoundaryArea().

_bcy

double const TriangleBoundary::_bcy

private

Referenced by IsWithinBoundaryArea().

_c

DoublePosition const TriangleBoundary::_c

private

Referenced by IsWithinBoundaryArea().

_cax

double const TriangleBoundary::_cax

private

Referenced by IsWithinBoundaryArea().

_cay

double const TriangleBoundary::_cay

private

Referenced by IsWithinBoundaryArea().