// 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*/