/*

* Copyright (c) 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:  Text recognition algorithm implementation.

*

*/

#include "HtiTextRcg.h"

#include <AknUtils.h>

const static TInt KDefaultStrategy = EHintEdge;

TInt CompareTPoint(const TPoint& aP1,const TPoint& aP2)

    {

    //this functions is used only to avoid equal points when creating FGA or BGA

    //so only equality of points is important, order doesnt matter

    if ( aP1.iY == aP2.iY )

        return aP1.iX - aP2.iX;

    return aP1.iY - aP2.iY;

    }

CHtiTextRcg::CHtiTextRcg()

    {

    iAvgDiffMin = KDefaultAvgDiffMin;

    //minimal SS for foreground, with plain color should be 0

    iFgSSMin = KDefaultFgSSMin;

    iFgAvgDiffMin = KDefaultFgAvgDiffMin;

    iFGAAmount = KDefaultFGAAmount;

    iBGAAmount = KDefaultBGAAmount;

    SetHint(KDefaultStrategy);

    }

CHtiTextRcg::~CHtiTextRcg()

    {

    iFGASet.Close();

    iBGASet.Close();

    }

void CHtiTextRcg::SetHint(TInt aHint)

    {

    //selects strategy and algorithm parameters

    switch ( aHint )

        {

        case EHintEdge:

            {

            //AA strategy

            iCurrentStrategy = EHintEdge;

            }

            break;

        case EHintNone:

        default:

            {

            //default strategy

            iCurrentStrategy = EHintNone;

            }

        }

    }

TBool CHtiTextRcg::RecognizeTextL(CFbsBitmap* aScreenshot,

                        const TDesC& aText,

                        const CFont* aFont,

                        TRect& aResult)

    {

HTI_LOG_FUNC_IN("RecognizeTextL");

    TInt returnValue = KWorstCase;

    CFbsBitmap* gray = ColorDownL(aScreenshot);

    CleanupStack::PushL(gray);

    switch ( iCurrentStrategy )

        {

        case EHintEdge:

            {

            returnValue = RecognizeAAL(gray,aText, aFont, aResult);

            }

            break;

        case EHintNone:

        default:

            {

            returnValue = RecognizeBinL(gray,aText, aFont, aResult);

            }

        }

    CleanupStack::PopAndDestroy(gray);

HTI_LOG_FUNC_OUT("RecognizeTextL");

    return returnValue < KSuccessThresold;

    }

TInt CHtiTextRcg::RecognizeBinL(CFbsBitmap* aScreenshot,

                            const TDesC& aText,

                            const CFont* aFont,

                            TRect& aResult)

{

    HTI_LOG_FUNC_IN("RecognizeBinL");

    CFbsBitmap* searchFirstLetter = GetTextBitmapL(aText, aFont, 1);

    CleanupStack::PushL(searchFirstLetter);

    HTI_LOG_FORMAT("pattern size w %d", searchFirstLetter->SizeInPixels().iWidth);

    HTI_LOG_FORMAT("pattern size h %d", searchFirstLetter->SizeInPixels().iHeight);

    if ( !AnalyzePatternL(searchFirstLetter) )

        {

        CleanupStack::PopAndDestroy(searchFirstLetter);

        return KWorstCase;

        }

    CFbsBitmap* searchText = GetTextBitmapL(aText, aFont);

    CleanupStack::PushL(searchText);

      //search range (0,0) - (reg.Size() - searchText.SizeInPixels)

    TPoint end(aScreenshot->SizeInPixels().iWidth, aScreenshot->SizeInPixels().iHeight);

    end -= searchText->SizeInPixels();

    end += TPoint(1,1);

    //search itself

    for ( TPoint p( 0, 0 ); p.iY < end.iY; p.iY++ )

        {

        for ( p.iX = 0; p.iX < end.iX; p.iX++ )

            {

            TInt t = ImageDiffBinSampleL(aScreenshot, p, searchFirstLetter);

            if ( t == 0 )

                {

                //check full word

                TInt wordD = ImageDiffBinFullL(aScreenshot, p, searchText);

                if ( wordD == 0 )

                    {

                    aResult.iTl.iX = p.iX;

                    aResult.iTl.iY = p.iY;

                    aResult.SetSize(searchText->SizeInPixels());

                    CleanupStack::PopAndDestroy(searchText);

                    CleanupStack::PopAndDestroy(searchFirstLetter);

                    HTI_LOG_FUNC_OUT("RecognizeBinL");

                    return 0;

                    }

                }

            }

        }

    CleanupStack::PopAndDestroy(searchText);

    CleanupStack::PopAndDestroy(searchFirstLetter);

    HTI_LOG_FUNC_OUT("RecognizeBinL");

    return KWorstCase;

}

TInt CHtiTextRcg::RecognizeAAL(CFbsBitmap* aScreenshot,

                            const TDesC& aText,

                            const CFont* aFont,

                            TRect& aResult)

{

    HTI_LOG_FUNC_IN("RecognizeAAL");

    CFbsBitmap* searchFirstLetter = GetTextBitmapL(aText, aFont, 1);

    CleanupStack::PushL(searchFirstLetter);

    if ( !AnalyzePatternL(searchFirstLetter) )

        {

        CleanupStack::PopAndDestroy(searchFirstLetter);

        return KWorstCase;

        }

    CFbsBitmap* searchText = GetTextBitmapL(aText, aFont);

    CleanupStack::PushL(searchText);

    //search range (0,0) - (reg.Size() - searchText.SizeInPixels)

    TPoint end(aScreenshot->SizeInPixels().iWidth, aScreenshot->SizeInPixels().iHeight);

    end -= searchText->SizeInPixels();

    end += TPoint(1,1);

    //search itself

    TInt min = KSuccessThresold;

    TInt wordMin = KSuccessThresold;

    for ( TPoint p( 0, 0 ); p.iY < end.iY; p.iY++ )

        {

        for ( p.iX = 0; p.iX < end.iX; p.iX++ )

            {

            TInt t = ImageDiffAASampleL(aScreenshot, p, searchFirstLetter);

            if ( t < min )

                {

                //check full word

                TInt wordD = ImageDiffAAFullL(aScreenshot, p, searchText);

                if ( wordD < wordMin )

                    {

                    wordMin = wordD;

                    min = t;

                    aResult.iTl.iX = p.iX;

                    aResult.iTl.iY = p.iY;

                    aResult.SetSize(searchText->SizeInPixels());

                    if ( wordMin == 0 )

                        {

                        CleanupStack::PopAndDestroy(searchText);

                        CleanupStack::PopAndDestroy(searchFirstLetter);

                        HTI_LOG_FUNC_OUT("RecognizeAAL");

                        return 0;

                        }

                    }

                }

            }

        }

    CleanupStack::PopAndDestroy(searchText);

    CleanupStack::PopAndDestroy(searchFirstLetter);

    HTI_LOG_FUNC_OUT("RecognizeAAL");

    return wordMin;

}

TBool CHtiTextRcg::AnalyzePatternL(CFbsBitmap * aPattern)

{

    HTI_LOG_FUNC_IN("AnalyzePatternL");

    if ( aPattern->SizeInPixels().iWidth == 0 ||

         aPattern->SizeInPixels().iHeight == 0 )

        {

        return EFalse;

        }

    //points are selected as follow

    //take pair of FG-BG points which located next to each other

    MinMax(aPattern,

           iMaskFgColor, //min, black font

           iMaskBgColor);//max, white bg

    if ( iMaskFgColor == iMaskBgColor ) //pattern is empty

        {

        return EFalse;

        }

    TLinearOrder<TPoint> pointOrder(CompareTPoint);

    TSize borders = aPattern->SizeInPixels();

    iFGASet.Reset();

    iBGASet.Reset();

    TBitmapUtil bmpIterator(aPattern);

    //lock bitmap

    bmpIterator.Begin( TPoint(0,0));

    //first take center lines and find take at least two pairs

    //vertical1

    TPoint startPoint(borders.iWidth/2, 0);

    bmpIterator.SetPos(startPoint);

    TInt lastColor = bmpIterator.GetPixel()&0xff;

    TInt lastColorPos = 0;

    bmpIterator.IncYPos();

    TInt i=1;

    TInt found = 0;

    while ( found < 2 && i < borders.iHeight )

        {

        TInt c = bmpIterator.GetPixel()&0xff;

        if ( lastColor != c )

            {

            if ( c == iMaskFgColor )

                {

                iFGASet.InsertInOrder(TPoint(startPoint.iX, i), pointOrder);

                iBGASet.InsertInOrder(TPoint(startPoint.iX, lastColorPos), pointOrder);

                lastColor = c;

                lastColorPos = i;

                ++found;

                }

            else if ( c == iMaskBgColor )

                {

                iBGASet.InsertInOrder(TPoint(startPoint.iX, i), pointOrder);

                iFGASet.InsertInOrder(TPoint(startPoint.iX, lastColorPos), pointOrder);

                lastColor = c;

                lastColorPos = i;

                ++found;

                }

            }

        else

            {

            lastColorPos = i;

            }

        ++i;

        bmpIterator.IncYPos();

        }

    //horizontal1

    startPoint.SetXY(0,borders.iHeight/2);

    bmpIterator.SetPos(startPoint);

    lastColor = bmpIterator.GetPixel()&0xff;

    bmpIterator.IncXPos();

    i=1;

    found = 0;

    lastColorPos = 0;

    while ( found < 2 && i < borders.iWidth )

        {

        TInt c = bmpIterator.GetPixel()&0xff;

        if ( lastColor != c )

            {

            if ( c == iMaskFgColor )

                {

                iFGASet.InsertInOrder(TPoint(i, startPoint.iY), pointOrder);

                iBGASet.InsertInOrder(TPoint(lastColorPos, startPoint.iY), pointOrder);

                lastColor = c;

                lastColorPos = i;

                ++found;

                }

            else if ( c == iMaskBgColor )

                {

                iBGASet.InsertInOrder(TPoint(i, startPoint.iY), pointOrder);

                iFGASet.InsertInOrder(TPoint(lastColorPos, startPoint.iY), pointOrder);

                lastColor = c;

                lastColorPos = i;

                ++found;

                }

            }

        else

            {

            lastColorPos = i;

            }

        ++i;

        bmpIterator.IncXPos();

        }

    //unlock bitmap

    bmpIterator.End();

    iFGAAmount = iFGASet.Count();

    iBGAAmount = iBGASet.Count();

    HTI_LOG_FUNC_OUT("AnalyzePatternL");

    return ETrue;

}

TInt CHtiTextRcg::ImageDiffAASampleL(CFbsBitmap * aBitmap1, TPoint aOrigin1,

                 CFbsBitmap * aBitmap2)

    {

    if (iFGASet.Count()==0 || iBGASet.Count()==0)

        return KWorstCase;

    TSize aSize = aBitmap2->SizeInPixels();

    //straight average difference

    TBitmapUtil bmpIterator1(aBitmap1);

    TBitmapUtil bmpIterator2(aBitmap2);

    bmpIterator1.Begin( aOrigin1 );

    //1. check FGA points are equal

    bmpIterator1.SetPos( aOrigin1 + iFGASet[0]);

    iTestFgColor = bmpIterator1.GetPixel()&0xff;

    for ( TInt i = 1; i < iFGAAmount;++i )

        {

        bmpIterator1.SetPos( aOrigin1 + iFGASet[i]);

        TInt c = bmpIterator1.GetPixel()&0xff;

        if ( Abs(c-iTestFgColor) > iFgAvgDiffMin )

            {

            bmpIterator2.End();

            bmpIterator1.End();

            return KWorstCase;

            }

        }

    // if we are here all FGA points are equal to colorFGA

    //2. check that avg BGA point value is not equal to colorFGA

    iTestBgColor = 0;

    for ( TInt i = 0; i < iBGAAmount; ++i )

        {

        bmpIterator1.SetPos( aOrigin1 + iBGASet[i]);

        iTestBgColor += bmpIterator1.GetPixel()&0xff;

        }

    iTestBgColor /= iBGAAmount;

    //if difference is too small leave with false

    if ( Abs(iTestBgColor-iTestFgColor) <  iAvgDiffMin )

        {

        bmpIterator2.End();

        bmpIterator1.End();

        return KWorstCase;

        }

    //all checking based on FGA and BGA are correct, chance to have match

    //3. calculate sum of diff between colorFGA and ALL FG points

    bmpIterator1.End();

    bmpIterator1.Begin( aOrigin1 );

    bmpIterator2.Begin( TPoint(0,0), bmpIterator1 );

    TInt nofF = 0;

    TInt sum = 0;

    TBool iterFlag = EFalse;

    TInt rowDelta = 2;

    TInt columnDelta = 1;

    TBool intellFlagBG;

    iTestNormCoef = (Abs(iMaskFgColor-iMaskBgColor)<<KNormCoefAcc)/Abs(iTestFgColor-iTestBgColor);

    for ( TInt i = 0; i < aSize.iHeight; i += rowDelta )

        {

        intellFlagBG = EFalse;

        for ( TInt j = 0; j < aSize.iWidth; j += columnDelta )

            {

            TInt c1 = (bmpIterator1.GetPixel())&0xff;

            TInt c2 = (bmpIterator2.GetPixel())&0xff;

            if ( c2 != iMaskBgColor ) // if foreground

                {

                if ( c2 == iMaskFgColor ) //should be "pure" FG

                    {

                        if (  Abs( c1 - iTestFgColor ) > iFgAvgDiffMin )

                        {

                            bmpIterator2.End();

                            bmpIterator1.End();

                            return KWorstCase;

                        }

                        intellFlagBG = ETrue;

                    }

                else if ( intellFlagBG ) // AA pixels

                    {

                    //calculate diff. in relative diff in aa pixel

                    //in mask and searh image

                    //based on assumtion that aa pixels color

                    // relative to fg color should correlate

                    TInt normD = (Abs(c1-iTestFgColor)*iTestNormCoef)>>KNormCoefAcc;

                    sum += Abs(Abs(iMaskFgColor-c2) - normD );

                    ++nofF;

                    intellFlagBG = EFalse;

                    }

                }

            for ( TInt l = 0; l < columnDelta; l++ )

                {

                if ( iterFlag )

                    {

                    bmpIterator1.DecXPos();

                    bmpIterator2.DecXPos();

                    }

                else

                    {

                    bmpIterator1.IncXPos();

                    bmpIterator2.IncXPos();

                    }

                }

            }

        for ( int k = 0; k < rowDelta; k++ )

        {

            bmpIterator1.IncYPos();

            bmpIterator2.IncYPos();

        }

        for ( int l = 0; l < columnDelta; l++ )

            {

            if ( iterFlag )

                {

                bmpIterator1.IncXPos();

                bmpIterator2.IncXPos();

                }

            else

                {

                bmpIterator1.DecXPos();

                bmpIterator2.DecXPos();

                }

            }

        iterFlag = !iterFlag;

        }

    bmpIterator2.End();

    bmpIterator1.End();

    if ( nofF == 0 )

        {

        return 0;

        }

    return sum / nofF;

    }

TInt CHtiTextRcg::ImageDiffAAFullL(CFbsBitmap * aBitmap1, TPoint aOrigin1,

                 CFbsBitmap * aBitmap2)

    {

    TSize aSize = aBitmap2->SizeInPixels();

    //straight average difference

    TBitmapUtil bmpIterator1(aBitmap1);

    TBitmapUtil bmpIterator2(aBitmap2);

    bmpIterator1.Begin( aOrigin1 );

    bmpIterator2.Begin( TPoint(0,0), bmpIterator1 );

    TInt nofF = 0;

    TInt sumF = 0;

    TBool intellFlagBG;

    TBool iterFlag = EFalse;

    TInt rowDelta = 2;

    TInt columnDelta = 1;

    for ( TInt i = 0; i < aSize.iHeight; i += rowDelta )

        {

        intellFlagBG = EFalse;

        for ( TInt j = 0; j < aSize.iWidth; j += columnDelta )

            {

            TInt c1 = ( bmpIterator1.GetPixel() ) & 0xff;

            TInt c2 = ( bmpIterator2.GetPixel() ) & 0xff;

            if ( c2 != iMaskBgColor ) // if foreground

                {

                if ( c2 == iMaskFgColor ) //should be pure FG

                    {

                        if (  Abs(c1 - iTestFgColor) > iFgAvgDiffMin )

                        {

                            bmpIterator2.End();

                            bmpIterator1.End();

                            return KWorstCase;

                        }

                        intellFlagBG = ETrue;

                    }

                else if ( intellFlagBG ) // AA pixels

                    {