PMBezierCurve Class Reference

#include <PMBezierCurve.h>

Public Types
enum	{ kBezierAdjustReflectedp1 = 1, kBezierAdjustReflectedp2 = 2, kBezierAdjustRotatedp1 = 4, kBezierAdjustRotatedp2 = 8 }
typedef base_type	data_type

Public Member Functions
	PMBezierCurve ()
	PMBezierCurve (const PMPoint &p0, const PMPoint &p1, const PMPoint &p2, const PMPoint &p3)
	PMBezierCurve (const PMPoint &p0p1, const PMPoint &p2p3)
	PMBezierCurve (const PMPoint &p)
const PMPoint &	GetP0 () const
const PMPoint &	GetP1 () const
const PMPoint &	GetP2 () const
const PMPoint &	GetP3 () const
const PMPoint &	GetNthPoint (int32 n) const
void	SetP0 (const PMPoint &p)
void	SetP1 (const PMPoint &p)
void	SetP2 (const PMPoint &p)
void	SetP3 (const PMPoint &p)
void	SetNthPoint (int32 n, const PMPoint &p)
PMRect	GetCtrlPtBounds () const
PMRect	GetPathBounds () const
void	TransformPoints (const PMMatrix &xForm)
bool16	FindParameter (const PMPoint &p, const PMReal &hitzone, PMReal *retU) const
PMPoint	Evaluate (const PMReal &u) const
PMPoint	EvaluateSlope (const PMReal &u) const
void	EvaluatePointAndSlope (const PMReal &u, PMPoint *outP, PMPoint *outSlope) const
int32	GetStepSize (const PMReal &flatness) const
void	FlattenCurve (PMPoint *pts, int32 stepSize)
int32	FindMinMax (PMReal *uResult) const
void	SubDivide (const PMReal &u, PMBezierCurve *bezLeft, PMBezierCurve *bezRight) const
void	SubSegment (const PMReal &begU, const PMReal &endU, PMBezierCurve *subSegment) const
void	DivideIntoPathPoints (const PMReal u, PMPathPoint *ptBefore, PMPathPoint *ptAt, PMPathPoint *ptAfter)
void	ReadWrite (IPMStream *iPMStream)
void	operator*= (const PMReal &a)
void	operator/= (const PMReal &a)
PMBezierCurve &	operator= (const PMBezierCurve &rhs)
PMReal	PrivateFindParameter (const PMReal &startP, const PMReal &endP, const PMReal &coord, bool16 isXCoord, bool16 *oneCrossing) const
PMReal	FindParameterByAverage (PMReal t0, PMReal t1, const PMPoint &p) const
bool16	HitTest (const PMRect &r) const
int16	AdjustToPassThroughPoint (const PMPoint &p, const PMReal &t)
bool16	PreAdjustCurve (const PMReal &t, PMPoint &t0, PMPoint &t3, PMPoint &c, PMPoint &d, PMPoint &e) const
int16	DoAdjustCurve (const PMPoint &m, const PMReal &t, const PMPoint &t0, const PMPoint &t3, const PMPoint &c, const PMPoint &d, const PMPoint &e, bool16 parallel)

Static Public Member Functions
static void	Reduce (PMPoint *P, const PMPoint &A, const PMPoint &B, const PMReal &u)

Protected Attributes
PMPoint	fP0
PMPoint	fP1
PMPoint	fP2
PMPoint	fP3

Friends
PMBezierCurve	operator* (const PMReal &c, const PMBezierCurve &pt)
PMBezierCurve	operator/ (const PMBezierCurve &numer, const PMReal &denom)
bool16	operator== (const PMBezierCurve &a, const PMBezierCurve &b)
bool16	operator!= (const PMBezierCurve &a, const PMBezierCurve &b)

Detailed Description

A C++ class for Bezier curve. The Bezier curve is defined by 4 points.

Member Enumeration Documentation

anonymous enum

Defines the return values for AdjustThroughPoint

Enumerator
kBezierAdjustReflectedp2	same slope, but opposite side of p0
kBezierAdjustRotatedp1	same slope, but opposite side of p3
kBezierAdjustRotatedp2	p0 to p1 has different slope

Constructor & Destructor Documentation

PMBezierCurve::PMBezierCurve

(

)

Constructs an empty Bezier.

PMBezierCurve::PMBezierCurve	(	const PMPoint &	p0,
		const PMPoint &	p1,
		const PMPoint &	p2,
		const PMPoint &	p3
	)

Contructs a Bezier from four points.

Parameters

P0	is the first point.
P1	is the second point.
P2	is the third point.
P3	is the fourth point.

PMBezierCurve::PMBezierCurve	(	const PMPoint &	p0p1,
		const PMPoint &	p2p3
	)

Constructs a Bezier from two points. This will make p0 = p1 and p2 = p3

Parameters

p0p1	the first point.
p2p3	is the second point.

PMBezierCurve::PMBezierCurve

(

const PMPoint &

p

)

Construct a degenerate curve where p0 = p1 = p2 = p3

Parameters

p	is the point.

Member Function Documentation

void PMBezierCurve::DivideIntoPathPoints	(	const PMReal	u,
		PMPathPoint *	ptBefore,
		PMPathPoint *	ptAt,
		PMPathPoint *	ptAfter
	)

Divide the curve at u and return the path points representing the curve.

PMPoint PMBezierCurve::Evaluate

(

const PMReal &

u

)

const

Evaluate the curve at the given parameter.

Parameters

u	is the parameter where 0 <= u <= 1.0

void PMBezierCurve::EvaluatePointAndSlope	(	const PMReal &	u,
		PMPoint *	outP,
		PMPoint *	outSlope
	)		const

This is faster than calling Evaluate and EvaluateSlope separately.

PMPoint PMBezierCurve::EvaluateSlope

(

const PMReal &

u

)

const

Find the slope at the given u.

Parameters

u

int32 PMBezierCurve::FindMinMax

(

PMReal *

uResult

)

const

Find the min and max paramesters. Returns the number of paramesters found. Max is 4. FindMinMax does not check param == 0.0 or param == 1.0

Parameters

uResult

contains the resulting parameters.

Returns

the number of paramesters.

bool16 PMBezierCurve::FindParameter	(	const PMPoint &	p,
		const PMReal &	hitzone,
		PMReal *	retU
	)		const

Returns whether the point is within hit zone of the curve. If so, it fills out the parameter location.

Parameters

p	is the point to check.
hitzone	is the hit zone.
retU	?

Returns

true if point is within the hit zone of the curve.

void PMBezierCurve::FlattenCurve	(	PMPoint *	pts,
		int32	stepSize
	)

Convert the Bezier to (1 << stepSize) + 1 number of points.

Parameters

pts	is the resulting points.
stepSize	is the step size.

PMRect PMBezierCurve::GetCtrlPtBounds

(

)

const

Return the bounding box of the curve including control points. If a single point the bbox is empty centered on the point.

Returns

the bounding box of the curve.

const PMPoint& PMBezierCurve::GetNthPoint

(

int32

n

)

const

Return the point at the given index, 0 <= n <= 3

Parameters

n	is the index.

const PMPoint& PMBezierCurve::GetP0 ( ) const

inline

Returns

the first point.

const PMPoint& PMBezierCurve::GetP1 ( ) const

inline

Returns

the second point.

const PMPoint& PMBezierCurve::GetP2 ( ) const

inline

Returns

the third point.

const PMPoint& PMBezierCurve::GetP3 ( ) const

inline

Returns

the fourth point.

PMRect PMBezierCurve::GetPathBounds

(

)

const

Returns the bounds of the path. This does not include the control points

Returns

the bounding box of the path not including control points.

int32 PMBezierCurve::GetStepSize

(

const PMReal &

flatness

)

const

Returns a step value that when passed into FlattenCurve will result in the given flatness.

Parameters

flatness

is the desired flatness, where 0 < flatness <= 1.0

bool16 PMBezierCurve::HitTest

(

const PMRect &

r

)

const

Returns whether the given rectangle intersects the curve.

Parameters

r	is the rectangle to test.

Returns

true if given rectangle intersects the curve.

void PMBezierCurve::ReadWrite

(

IPMStream *

iPMStream

)

Read/Write bezier from/to given stream.

Parameters

iPMStream

is the stream.

static void PMBezierCurve::Reduce ( PMPoint *  P, const PMPoint &  A, const PMPoint &  B, const PMReal &  u  )

static

Reduce the Bezier. The equation for this method is P = A*(1-u) + B*u

void PMBezierCurve::SetNthPoint	(	int32	n,
		const PMPoint &	p
	)

Sets the nth point to p.

Parameters

n	is the index of the point.
p	is the new point.

void PMBezierCurve::SetP0 ( const PMPoint &  p )

inline

Sets the first point to p.

Parameters

p	specifies the new first point.

void PMBezierCurve::SetP1 ( const PMPoint &  p )

inline

Sets the second point to p.

Parameters

p	specifies the new second point.

void PMBezierCurve::SetP2 ( const PMPoint &  p )

inline

Sets the third point to p.

Parameters

p	specifies the new third point.

void PMBezierCurve::SetP3 ( const PMPoint &  p )

inline

Sets the fourth point to p.

Parameters

p	specifies the new fourth point.

void PMBezierCurve::SubDivide	(	const PMReal &	u,
		PMBezierCurve *	bezLeft,
		PMBezierCurve *	bezRight
	)		const

Subdivide curve into two other curves at the given parameter.

Parameters

u	is the parameter.
bezLeft	is the resulting left bezier.
bezRight	is the resulting right bezier.

void PMBezierCurve::SubSegment	(	const PMReal &	begU,
		const PMReal &	endU,
		PMBezierCurve *	subSegment
	)		const

Take a segment from begU to endU.

Parameters

begU
endU
subSegment	is the resulting bezier from begU and endU.

void PMBezierCurve::TransformPoints

(

const PMMatrix &

xForm

)

Transform the curve with the given matrix

Parameters

xForm

is the matrix to transform by.

Friends And Related Function Documentation

bool16 operator!= ( const PMBezierCurve &  a, const PMBezierCurve &  b  )

friend

Compare two PMBezierCurve

Parameters

a	is one beszier curve.
b	is the other bezier curve.

Returns

true it a and b are not equal.

bool16 operator== ( const PMBezierCurve &  a, const PMBezierCurve &  b  )

friend

Compare two PMBezierCurve

Parameters

a	is one beszier curve.
b	is the other bezier curve.

Returns

true it a and b are equal.