1 /****************************************************************************

     2 **

     3 ** Copyright (C) 2008-2010 Nokia Corporation and/or its subsidiary(-ies).

     4 ** All rights reserved.

     5 ** Contact: Nokia Corporation (developer.feedback@nokia.com)

     6 **

     7 ** This file is part of the HbCore module of the UI Extensions for Mobile.

     8 **

     9 ** GNU Lesser General Public License Usage

    10 ** This file may be used under the terms of the GNU Lesser General Public

    11 ** License version 2.1 as published by the Free Software Foundation and

    12 ** appearing in the file LICENSE.LGPL included in the packaging of this file.

    13 ** Please review the following information to ensure the GNU Lesser General

    14 ** Public License version 2.1 requirements will be met:

    15 ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

    16 **

    17 ** In addition, as a special exception, Nokia gives you certain additional

    18 ** rights.  These rights are described in the Nokia Qt LGPL Exception

    19 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

    20 **

    21 ** If you have questions regarding the use of this file, please contact

    22 ** Nokia at developer.feedback@nokia.com.

    23 **

    24 ****************************************************************************/

    25 

    26 #include "hbvgbceffect_p.h"

    27 #include "hbvgbceffect_p_p.h"

    28 #include <QPainter>

    29 

    30 /*!

    31  * \class HbVgBcEffect

    32  *

    33  * \brief OpenVG-based brightness-contrast filter effect.

    34  *

    35  * \internal

    36  */

    37 

    38 HbVgBcEffectPrivate::HbVgBcEffectPrivate()

    39     : brightness(0), contrast(1)

    40 {

    41 }

    42 

    43 HbVgBcEffect::HbVgBcEffect(QObject *parent)

    44     : HbVgEffect(*new HbVgBcEffectPrivate, parent)

    45 {

    46 }

    47 

    48 HbVgBcEffect::HbVgBcEffect(HbVgBcEffectPrivate &dd, QObject *parent)

    49     : HbVgEffect(dd, parent)

    50 {

    51 }

    52 

    53 HbVgBcEffect::~HbVgBcEffect()

    54 {

    55 }

    56 

    57 qreal HbVgBcEffect::brightness() const

    58 {

    59     Q_D(const HbVgBcEffect);

    60     return d->brightness;

    61 }

    62 

    63 void HbVgBcEffect::setBrightness(qreal brightness)

    64 {

    65     Q_D(HbVgBcEffect);

    66     if (d->brightness == brightness)

    67         return;

    68     d->brightness = brightness;

    69     updateEffect();

    70     emit brightnessChanged(brightness);

    71 }

    72 

    73 qreal HbVgBcEffect::contrast() const

    74 {

    75     Q_D(const HbVgBcEffect);

    76     return d->contrast;

    77 }

    78 

    79 void HbVgBcEffect::setContrast(qreal contrast)

    80 {

    81     Q_D(HbVgBcEffect);

    82     if (d->contrast == contrast)

    83         return;

    84     d->contrast = contrast;

    85     updateEffect();

    86     emit contrastChanged(contrast);

    87 }

    88 

    89 QRectF HbVgBcEffect::boundingRectFor(const QRectF &rect) const

    90 {

    91     return rect;

    92 }

    93 

    94 void HbVgBcEffect::performEffect(QPainter *painter,

    95                                    const QPointF &offset,

    96                                    const QVariant &vgImage,

    97                                    const QSize &vgImageSize)

    98 {

    99 #ifdef HB_EFFECTS_OPENVG

   100     QPixmap cachedPm = cached(vgImageSize);

   101     if (!cachedPm.isNull()) {

   102         painter->drawPixmap(offset, cachedPm);

   103         return;

   104     }

   105 

   106     Q_D(HbVgBcEffect);

   107     VGImage srcImage = vgImage.value<VGImage>();

   108     VGImage dstImage = d->ensurePixmap(&d->dstPixmap, vgImageSize);

   109     qreal opacity = clamp(d->opacity, 0.0f, 1.0f);

   110     if (opacity > HBVG_EPSILON) {

   111         if (d->paramsChanged) {

   112             // brightness [-1, 1]

   113             const VGfloat offset_br = clamp(d->brightness, -1.0f, 1.0f);

   114             const VGfloat scale_br = 1.0f - 0.5f * ((offset_br < 0.0f) ? -offset_br : offset_br);

   115     

   116             // contrast [0, N]

   117             const VGfloat scale_con = clamp(d->contrast, 0.0f, 100.0f);

   118             const VGfloat offset_con = -0.5f * scale_con + 0.5f ;

   119     

   120             // combine the effects of brightness and contrast

   121             const VGfloat off = offset_br + offset_con;

   122             const VGfloat sc  = scale_br * scale_con;

   123 

   124             // take opacity into account

   125             const VGfloat o = (VGfloat) opacity;

   126             const VGfloat oOff = off * o;

   127             const VGfloat oSc  = (sc * o) + (1.0f - o);

   128     

   129             d->colorMatrix[0] = oSc;

   130             d->colorMatrix[1] = 0.0f;

   131             d->colorMatrix[2] = 0.0f;

   132             d->colorMatrix[3] = 0.0f;

   133             d->colorMatrix[4] = 0.0f;

   134             d->colorMatrix[5] = oSc;

   135             d->colorMatrix[6] = 0.0f;

   136             d->colorMatrix[7] = 0.0f;

   137             d->colorMatrix[8] = 0.0f;

   138             d->colorMatrix[9] = 0.0f;

   139             d->colorMatrix[10] = oSc;

   140             d->colorMatrix[11] = 0.0f;

   141             d->colorMatrix[12] = 0.0f;

   142             d->colorMatrix[13] = 0.0f;

   143             d->colorMatrix[14] = 0.0f;

   144             d->colorMatrix[15] = 1.0f;

   145             d->colorMatrix[16] = oOff;

   146             d->colorMatrix[17] = oOff;

   147             d->colorMatrix[18] = oOff;

   148             d->colorMatrix[19] = 0.0f;

   149         }

   150         vgColorMatrix(dstImage, srcImage, d->colorMatrix);

   151         painter->drawPixmap(offset, d->dstPixmap);

   152         tryCache(d->dstPixmap);

   153     } else {

   154         painter->drawPixmap(offset, d->srcPixmap);

   155     }

   156 #else

   157     Q_UNUSED(painter);

   158     Q_UNUSED(offset);

   159     Q_UNUSED(vgImage);

   160     Q_UNUSED(vgImageSize);

   161 #endif

   162 }