// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of "Eclipse Public License v1.0"

 // which accompanies this distribution, and is available

 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

 //

 // Initial Contributors:

 // Nokia Corporation - initial contribution.

 //

 // Contributors:

 //

 // Description:

 //

 #ifndef SWDIRECTGDIPOLYGON_H

 #define SWDIRECTGDIPOLYGON_H

 /**

 @file

 @internalComponent

 */

 #include "directgdiadapter.h"

 #include <gdi.h>

 #include <e32base.h>

 /**

 A utility class to efficiently fill polygons.

 @see CSwDirectGdiEngine::PolyFill

 @see CSwDirectGdiEngine::PolyFillLarge

 */

 NONSHARABLE_CLASS(CSwDirectGdiPolygonFiller) : public CBase

 	{

 public:

 	/**

 	Describes how pixels are to be displayed in the polygon. aUsage should be set to

 	one of these values before CSwDirectGdiPolygonFiller::Construct is used.

 	*/

 	enum TUsage

 		{

 		/**

 		A request for all pixel runs in sequential order.

 		*/

 		EGetAllPixelRunsSequentially,

 		/**

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

 		*/

 		EGetPixelRunsSequentiallyForSpecifiedScanLines

 		};

 public:

 	CSwDirectGdiPolygonFiller();

 	~CSwDirectGdiPolygonFiller();

 	void Construct(const TArray<TPoint>* aPointArray, DirectGdi::TFillRule aFillRule,TUsage aUsage=EGetAllPixelRunsSequentially); // N.B. this cannot fail

 	void Construct(const TPoint* aPointList,TInt aNumPoints, DirectGdi::TFillRule aFillRule, TUsage aUsage=EGetAllPixelRunsSequentially); // N.B. this cannot fail

 	void Reset();

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

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

 private: // data-types for the fast algorithm

 	struct SFastEdge

 		{

 		TInt upperVertex;

 		TInt lowerVertex;

 		TInt firstVertex;

 		};

 	struct SFastScanLineIntersection;

 	struct SFastActiveEdge

 		{

 		SFastEdge* edgePtr;

 		TLinearDDA lineGenerator;

 		SFastScanLineIntersection* scanLineIntersectionPtr;

 		};

 	struct SFastScanLineIntersection

 		{

 		TInt firstPixel;

 		TInt lastPixel;

 		SFastActiveEdge* activeEdgePtr;

 		};

 private: // data-types for the slow algorithm

 	struct SSlowScanLineIntersection

 		{

 		TInt firstPixel;

 		TInt lastPixel;

 		TInt firstVertexOfEdge;

 		};

 private: // data-types for both algorithms

 	struct SFastData

 		{

 		TPoint* vertexList;

 		SFastEdge* edgeList;

 		SFastActiveEdge* activeEdgeList;

 		SFastScanLineIntersection* scanLineIntersectionList;

 		TInt numActiveEdges;

 		TInt numScanLineIntersections;

 		TInt nextEdgeToActivate;

 		};

 	struct SSlowData

 		{

 		enum {EStoreSize=8};

 		TLinearDDA lineGenerator;

 		SSlowScanLineIntersection scanLineIntersectionList[EStoreSize];

 		TInt numIntersectionsWithSameFirstPixelPreviouslyMet;

 		TInt numIntersectionsWithSameFirstPixelMetThisTime;

 		TInt numScanLineIntersections;

 		TBool scanLineComplete;

 		TInt firstPixelOfLastIntersectionInPrevBuffer;

 		};

 private:

 	void Construct(DirectGdi::TFillRule aFillRule, TUsage aUsage);

 	void FastHandleVertexIntersection(TInt& aCurrentActiveEdge, TBool aIsLowerVertex);

 	void SetFastIntersection(SFastActiveEdge& aActiveEdge, SFastScanLineIntersection& aScanLineIntersection);

 	void SlowHandleVertexIntersection(SSlowScanLineIntersection& aScanLineIntersection, TInt& aVertexStartingCurrentEdge,TBool aIsLowerVertex);

 	void JumpToCurrentScanLine(TLinearDDA& aLineGenerator, const TPoint& aUpper, const TPoint& aLower,TPoint& aStartPos, TPoint& aEndPos) const;

 	const TPoint& Point(TInt aIndex);

 private:

 	const TArray<TPoint>* iPointArray; // not owned by the class

 	DirectGdi::TFillRule iFillRule;

 	TBool iUseFastAlgorithm;

 	TInt iNumVertexes;

 	TBool iToggler; // used by EAlternate fill-rule

 	TInt iNestingLevel; // used by EWinding fill-rule

 	TInt iScanLineIntersection;

 	TInt iRightMostPixelOnScanLine;

 	TInt iFirstVertex;

 	TBool iPolygonIsAllHorizontal;

 	TInt iFirstScanLine;

 	TInt iLastScanLine;

 	TInt iCurrentScanLine;

 	SFastData iFastData;

 	SSlowData iSlowData;

 private:

 	friend class TCompareEdgesUpperY;

 	friend class TCompareActiveEdgesFirstVertex;

 	friend class TCompareScanLineIntersectionsFirstPixel;

 	friend class TSwapEdges;

 	friend class TSwapActiveEdges;

 	friend class TSwapScanLineIntersections;

 	};

 #endif /*SWDIRECTGDIPOLYGON_H*/