ILCircle Interface Reference

This interface represents a single circle(LCircle object). More...

Inheritance diagram for ILCircle:

Public Member Functions
double	Concentric (ILCircle *circle)
void	Draw (BOOL bFill, HDC hdc, double zoomX, double zoomY, double panX, double panY)
void	FromAnnulusRegion (ILAnnulusRegion *val)
void	FromCircleRegion (ILCircleRegion *val)
ILArc *	GetArc (double aStart, double aEnd)
double	GetArea ()
ILPoint *	GetCenter ()
double	GetPerimeter ()
LPVIntersectType	IntersectLine (ILLine *line, ILPoints **intersectPoints)
LPVPointTestResult	PointTest (ILPoint *point)
ILPolygon *	Resample (int num)
void	Set (double x, double y, double r)
ILAnnulusRegion *	ToAnnulusRegion (int inExp, int outExp)
ILCircleRegion *	ToCircleRegion ()
ILCircle *	Transform (ILTransform *tf)
ILCircle *	Translate (double offsetX, double offsetY)
Public Member Functions inherited from ILGeomObject
void	Drag (LPVGeomHandle geomHandle, int posX, int posY, double zoomX, double zoomY, double panX, double panY)
void	EnableHandle (LPVGeomHandle geomHandle, BOOL enabled)
LPVGeomHandle	HitTest (int posX, int posY, double zoomX, double zoomY, double panX, double panY)
void	ScaleTo (double factorX, double factorY)
void	TransformTo (ILTransform *tf)
void	TranslateTo (double offsetX, double offsetY)
Public Member Functions inherited from ILObject
ILObject *	Copy ()
LPVErrorCode	Load (LString filename)
void	Reset ()
LPVErrorCode	Save (LString filename)
BOOL	Valid ()

Properties
double	Radius [get, set]
	The radius of the circle.
double	X [get, set]
	The x-coordinate of the circle's center point.
double	Y [get, set]
	The y-coordinate of the circle's center point.
Properties inherited from ILObject
LString	Name [get, set]
	Name of the object. By default, the object has no name. In most cases, LPV classes don't make use of the names. The name is drawn on canvas around the object if ILDrawable::SetDrawName() is enabled. More...

Detailed Description

This interface represents a single circle(LCircle object).

Member Function Documentation

Concentric()

double Concentric

(

ILCircle *

circle

)

Evaluate whether this and the input circle are concentric

Parameters

[in]

circle

The input circle

Return values

result

Return the evaluation result, it's a value in (0, 1). For two perfect concentric circles, it's 1.

Draw()

void Draw	(	BOOL	bFill,
		HDC	hdc,
		double	zoomX,
		double	zoomY,
		double	panX,
		double	panY
	)

Draw the circle on HDC.

Parameters

[in]

bFill

Whether to fill the circle using current brush.

See also

Use Draw Functions

Remarks

This function is currently not available on Linux / MacOS platform.

FromAnnulusRegion()

void FromAnnulusRegion

(

ILAnnulusRegion *

val

)

Set placement of the circle from the input annulus region, the radii is set to the averaging of the inner and outer circle of the annulus region.

FromCircleRegion()

void FromCircleRegion

(

ILCircleRegion *

val

)

Set placement of the circle from the input circle region.

GetArc()

ILArc* GetArc	(	double	aStart,
		double	aEnd
	)

Create an arc starts clockwise from the aStart and ends to aEnd.

Parameters

[in]	aStart	The start angle in degrees
[in]	aEnd	The end angle in degrees

Return values

Return

the arc object

GetArea()

double GetArea

(

)

Get the area of the circle

Return values

val	Return the area value

GetCenter()

ILPoint* GetCenter

(

)

Get the center point of the circle

GetPerimeter()

double GetPerimeter

(

)

Get the perimeter of the circle

Return values

val	Return the perimeter value

IntersectLine()

LPVIntersectType IntersectLine	(	ILLine *	line,
		ILPoints **	intersectPoints
	)

Determines whether this circle intersects with the given line. Return the intersection points if they are intersected.

Parameters

[in]	line	The input line
[out]	intersectPoints	Output the intersection points, it should be an empty set for not-intersected case, or 1 point for tangent case, or 2 points for intersected case.

Return values

type	Return the intersection type depends on the count of intersection points which is on the line segment, Bounded (2), Partial (1) or Unbounded (0).

See also

ILLine::IntersectCircle().

PointTest()

LPVPointTestResult PointTest

(

ILPoint *

point

)

Determines whether the point is inside this circle, outside, or lies on the edge

Parameters

[in]

point

The input point

Return values

val	Return the test result

Resample()

ILPolygon* Resample

(

int

num

)

Resample the circle object into a closed polygon of the specified vertex count

Parameters

[in]

num

The count of the resampled vertexes, at least 3

Return values

result

Return the resampling result polygon

Set()

void Set	(	double	x,
		double	y,
		double	r
	)

Set placement of the circle

Parameters

[in]	x	The x-coordinate of the circle's center point
[in]	y	The y-coordinate of the circle's center point
[in]	r	The radius of the circle

ToAnnulusRegion()

ILAnnulusRegion* ToAnnulusRegion	(	int	inExp,
		int	outExp
	)

Generate an annulus region use the circle object with the given inside and outside expansion

Parameters

[in]	inExp	The expansion pixels from the circle's placement that generate the inner circle of the annulus region
[in]	outExp	The expansion pixels from the circle's placement that generate the outer circle of the annulus region

Return values

val	Return the circle region

ToCircleRegion()

ILCircleRegion* ToCircleRegion

(

)

Generate a circle region use the circle object

Transform()

ILCircle* Transform

(

ILTransform *

tf

)

Transform the circle via the given transformation and return a new circle. Note that for an affine or perspective transformation, the result circle is the bounding circle of the mapping result which may be an ellipse.

Parameters

[in]

tf

The transformation.

Return values

Return

the new circle

Translate()

ILCircle* Translate	(	double	offsetX,
		double	offsetY
	)

Translate the circle by the given offset and return a new circle

Parameters

[in]	offsetX	The x-coordinate of the offset
[in]	offsetY	The y-coordinate of the offset

Return values

result

Return the new circle