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CPolygonFiller Class Reference

class CPolygonFiller : public CBase

Inherits from

CPolygonFiller
- CBase

Nested Classes and Structures

Public Member Functions
	CPolygonFiller ()
	~CPolygonFiller ()
IMPORT_C void	Construct (const CArrayFix < TPoint > *, CGraphicsContext::TFillRule , TUsage )
IMPORT_C void	Construct (const TPoint *, TInt , CGraphicsContext::TFillRule , TUsage )
IMPORT_C void	GetNextPixelRun ( TBool &, TInt &, TInt &, TInt &)
IMPORT_C void	GetNextPixelRunOnSpecifiedScanLine ( TBool &, TInt , TInt &, TInt &)
IMPORT_C void	Reset ()

Private Member Functions
void	Construct ( CGraphicsContext::TFillRule , TUsage )
void	FastHandleVertexIntersection ( TInt &, TBool )
void	JumpToCurrentScanLine ( TLinearDDA &, const TPoint &, const TPoint &, TPoint &, TPoint &)
const TPoint &	Point ( TInt )
void	SetFastIntersection ( SFastActiveEdge &, SFastScanLineIntersection &)
void	SlowHandleVertexIntersection ( SSlowScanLineIntersection &, TInt &, TBool )

Inherited Functions
	CBase::CBase()
	CBase::Delete(CBase *)
	CBase::Extension_(TUint,TAny &,TAny )
	CBase::operator new(TUint)
	CBase::operator new(TUint,TAny *)
	CBase::operator new(TUint,TLeave)
	CBase::operator new(TUint,TLeave,TUint)
	CBase::operator new(TUint,TUint)
	CBase::~CBase()

Public Member Enumerations
enum	TUsage { EGetAllPixelRunsSequentially , EGetPixelRunsSequentiallyForSpecifiedScanLines }

Private Attributes
TInt	iCurrentScanLine
SFastData	iFastData
CGraphicsContext::TFillRule	iFillRule
TInt	iFirstScanLine
TInt	iFirstVertex
TInt	iLastScanLine
TInt	iNestingLevel
TInt	iNumVertexes
const CArrayFix < TPoint > *	iPointArray
const TPoint *	iPointList
TBool	iPolygonIsAllHorizontal
TInt	iRightMostPixelOnScanLine
TInt	iScanLineIntersection
SSlowData	iSlowData
TBool	iToggler
TBool	iUseFastAlgorithm

Constructor & Destructor Documentation

CPolygonFiller()

IMPORT_C

CPolygonFiller

(

)

Constructor which initializes all member data to zero, EFalse or null for TInt, TBool pointers respectively.

~CPolygonFiller()

IMPORT_C

~CPolygonFiller

(

)

Destructor calls reset on the polygon.

Member Functions Documentation

Construct(const CArrayFix< TPoint > *, CGraphicsContext::TFillRule, TUsage)

IMPORT_C void	Construct	(	const CArrayFix < TPoint > *	aPointArray,
			CGraphicsContext::TFillRule	aFillRule,
			TUsage	aUsage = EGetAllPixelRunsSequentially
		)

An overloaded version of Construct which allows the list of points to be passed in as a point array. Exactly the same behaviour and structure as above. This should not fail. This method does not require the number of nodes to be given as a parameter.

Parameters

const CArrayFix < TPoint > * aPointArray
CGraphicsContext::TFillRule aFillRule	How filling should be achieved, as described by a CGraphicsContext::TFillRule object.
TUsage aUsage = EGetAllPixelRunsSequentially	How the polygon should be used.

Construct(const TPoint *, TInt, CGraphicsContext::TFillRule, TUsage)

IMPORT_C void	Construct	(	const TPoint *	aPointList,
			TInt	aNumPoints,
			CGraphicsContext::TFillRule	aFillRule,
			TUsage	aUsage = EGetAllPixelRunsSequentially
		)

Takes a list of points to be the points for the new polygon and sets the number of points in the shape. After this has been done it transfers the task to Construct(aFillRule,aUsage) . This should not fail.

Parameters

const TPoint * aPointList	A list of points for the polygon.
TInt aNumPoints	The number of points in the list.
CGraphicsContext::TFillRule aFillRule	How filling should be achieved, as described by a CGraphicsContext::TFillRule object.
TUsage aUsage = EGetAllPixelRunsSequentially	How the polygon should be used, see TUsage enumeration.

Construct(CGraphicsContext::TFillRule, TUsage)

void	Construct	(	CGraphicsContext::TFillRule	aFillRule,
			TUsage	aUsage
		)	[private]

Parameters

CGraphicsContext::TFillRule aFillRule
TUsage aUsage

FastHandleVertexIntersection(TInt &, TBool)

void	FastHandleVertexIntersection	(	TInt &	aCurrentActiveEdge,
			TBool	aIsLowerVertex
		)	[private]

Parameters

TInt & aCurrentActiveEdge
TBool aIsLowerVertex

GetNextPixelRun(TBool &, TInt &, TInt &, TInt &)

IMPORT_C void	GetNextPixelRun	(	TBool &	aExists,
			TInt &	aScanLine,
			TInt &	aStart,
			TInt &	aEnd
		)

Method is used to calculate the locations of vertex interactions between the polygon and scan lines. An initial scan line is required. It calculates the start and end positions on the line. The method can use either the fast or slow polygon algorithm depending upon the state of aUsage. Polygon filling is also addressed by this method.

Parameters

TBool & aExists	Will be set to false if a polygon with no vertexes is passed in, otherwise ETrue on return.
TInt & aScanLine
TInt & aStart	The position on the scan line to start the run, on returned.
TInt & aEnd	The position on the scan line to end the run, returned.

GetNextPixelRunOnSpecifiedScanLine(TBool &, TInt, TInt &, TInt &)

IMPORT_C void	GetNextPixelRunOnSpecifiedScanLine	(	TBool &	aExists,
			TInt	aScanLine,
			TInt &	aStart,
			TInt &	aEnd
		)

Similar to GetNextPixelRun(aExists, aScanLine, aStart, aEnd) this method is used to draw the relevant vertex intersections for a polygon but only for an individual specified scan line. The method can use either the fast or slow polygon algorithm depending upon the state of aUsage.

Parameters

TBool & aExists	Will be set to false if the line does not pass through the polygon or if a polygon with no vertices is specified, otherwise ETrue on return.
TInt aScanLine
TInt & aStart	The position on the scan line to start the run, on returned.
TInt & aEnd	The position on the scan line to end the run, returned.

JumpToCurrentScanLine(TLinearDDA &, const TPoint &, const TPoint &, TPoint &, TPoint &)

void	JumpToCurrentScanLine	(	TLinearDDA &	aLineGenerator,
			const TPoint &	aUpper,
			const TPoint &	aLower,
			TPoint &	aStartPos,
			TPoint &	aEndPos
		)	const [private]

Parameters

TLinearDDA & aLineGenerator
const TPoint & aUpper
const TPoint & aLower
TPoint & aStartPos
TPoint & aEndPos

Point(TInt)

const TPoint &

Point

(

TInt

aIndex

)

[private]

Parameters

TInt aIndex

Reset()

IMPORT_C void

Reset

(

)

Frees any data held in the polygons lists of all edges, vertexs and scan lines and sets these values to NULL. It also has the feature of setting iUseFastAlgorithm = EFalse.

SetFastIntersection(SFastActiveEdge &, SFastScanLineIntersection &)

void	SetFastIntersection	(	SFastActiveEdge &	aActiveEdge,
			SFastScanLineIntersection &	aScanLineIntersection
		)	[private]

Parameters

SFastActiveEdge & aActiveEdge
SFastScanLineIntersection & aScanLineIntersection

SlowHandleVertexIntersection(SSlowScanLineIntersection &, TInt &, TBool)

void	SlowHandleVertexIntersection	(	SSlowScanLineIntersection &	aScanLineIntersection,
			TInt &	aVertexStartingCurrentEdge,
			TBool	aIsLowerVertex
		)	[private]

Parameters

SSlowScanLineIntersection & aScanLineIntersection
TInt & aVertexStartingCurrentEdge
TBool aIsLowerVertex

Member Enumerations Documentation

Enum TUsage

Describes how pixels are to be displayed in the polygon. aUsage should be select to one of these values before CPolygonFiller::Construct is used.

Enumerators

EGetAllPixelRunsSequentially	A request for all pixel runs in sequential order
EGetPixelRunsSequentiallyForSpecifiedScanLines	A request for all pixel runs in sequential order but only for specified lines.

[private]