CLine Class Reference

Line shape. More...

#include <Line.h>

Inheritance diagram for CLine:

Public Member Functions
	CLine (const Vector2 &, float)
	Constructor. More...
Public Member Functions inherited from CShape
	CShape (const CShapeDesc &)
	Constructor. More...
virtual	~CShape ()
	Destructor. More...
const eShape	GetShapeType () const
	Get shape type. More...
const eMotion	GetMotionType () const
	Get motion type. More...
const CAabb2D &	GetAABB () const
	Get AABB. More...
const bool	GetSensor () const
	Is this shape a sensor? More...
const Vector2 &	GetPos () const
	Get position. More...
void	SetPos (const Vector2 &)
	Set position. More...
void	SetAABBPoint (const Vector2 &)
	Set AABB point. More...
void	AddAABBPoint (const Vector2 &)
	Add AABB point. More...
void	SetCanCollide (bool=true)
	Turn collisions on or off. More...
const bool	GetCanCollide () const
	Get whether shape can collide. More...
virtual void	Rotate (const Vector2 &, float)
	Rotate. More...
virtual void	Reset ()
	Reset orientation. More...
virtual bool	PreCollide (CContactDesc &)
	Collision detection. More...
virtual void	move ()
	Translate. More...
const bool	GetRotating () const
	Get whether rotating. More...
void	SetRotating (bool)
	Start or stop rotating. More...
const float	GetOrientation () const
	Get orientation. More...
const float	GetRotSpeed () const
	Get rotation speed. More...
const Vector2 &	GetRotCenter () const
	Get rotation speed. More...
const float	GetElasticity () const
	Get elasticity. More...
void	SetOrientation (float)
	Set orientation. More...
void	SetRotSpeed (float)
	Set rotation speed. More...
void	SetRotCenter (const Vector2 &)
	Set center of rotation. More...
void *	GetUserPtr () const
	Get user pointer. More...
void	SetUserPtr (void *)
	Set user pointer. More...

Protected Member Functions
Vector2	Intersect (const CLine &)
	Get intersection point with line. More...
Vector2	ClosestPt (const Vector2 &)
	Get closest point on line. More...

Protected Attributes
float	m_fGradient = 0.0f
	Gradient.
float	m_fInverseGradient = 0.0f
	Inverse gradient.
float	m_fYIntercept = 0.0f
	Intercept with Y axis.
float	m_fXIntercept = 0.0f
	Intercept with X axis.
Protected Attributes inherited from CShape
eShape	m_eShapeType = eShape::Unknown
	Type of shape.
eMotion	m_eMotionType = eMotion::Static
	How shape moves.
float	m_fElasticity = 1.0f
	Elasticity, aka restitution, bounciness.
bool	m_bIsSensor = false
	Sensor only, no rebound on collision.
CAabb2D	m_cAABB
	Axially aligned bounding box in World Space.
bool	m_bCanCollide = true
	Can collide with other shapes.
float	m_fOrientation = 0.0f
	Orientation angle.
void *	m_pUser
	Spare pointer for user in case they might need one.
Vector2	m_vRotCenter
	Center of rotation.
float	m_fRotSpeed = 0.0f
	Rotation speed.
bool	m_bRotating = false
	Whether rotating.

Additional Inherited Members
Static Protected Attributes inherited from CShapeCommon
static float	m_fGravity = 0.0f
	Gravitational constant.
static float	m_fTimeStep = 0.0f
	Time step per animation frame (fictional).

Detailed Description

A line is infinite in both directions. It consists of its gradient \(m\) and \(y\)-incercept \(c\), that is, it has the equation \(y = mx + c\). The gradient can be infinite, in that case it has the equation \(x = b\), where \(b\) is its \(x\)-intercept. Note that there is no line descriptor class CLineDesc. That is to discourage the use of lines outside this project. If you are thinking of using one, I recommend that you use a line segment instead.

Constructor & Destructor Documentation

CLine()

CLine::CLine	(	const Vector2 &	p,
		float	m
	)

Given a point and a gradient, construct the unique line through that point with that gradient.

Parameters

p	Point.
m	Gradient.

Member Function Documentation

ClosestPt()

Vector2 CLine::ClosestPt ( const Vector2 &  p )

protected

Given a point, find the point on this line that is closest to it. This is done by intersecting this line with a line through p perpendicular to it.

Parameters

p

A point.

Returns

The point on this line that is closest to it.

Intersect()

Vector2 CLine::Intersect ( const CLine &  Line )

protected

Given another line, find the unique point that is on both lines if they are not parallel, otherwise fail. We have to careful whem one or both of the lines are vertical because vertical lines have infinite gradient.

Parameters

Line	A line to intersect with.

Returns

Point of intersection of this line with that one, if there is one.