/****************************************************************************

**

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

** All rights reserved.

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

**

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

**

** GNU Lesser General Public License Usage

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

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

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

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

** Public License version 2.1 requirements will be met:

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

**

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

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

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

**

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

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

**

****************************************************************************/

#include "hbvghsleffect_p.h"

#include "hbvghsleffect_p_p.h"

#include <QPainter>

#include <qmath.h>

/*!

 * \class HbVgHslEffect

 *

 * \brief OpenVG-based hue-saturation-lightness filter effect.

 *

 * \internal

 */

HbVgHslEffectPrivate::HbVgHslEffectPrivate()

    : hue(0), saturation(1), lightness(0)

{

}

HbVgHslEffect::HbVgHslEffect(QObject *parent)

    : HbVgEffect(*new HbVgHslEffectPrivate, parent)

{

}

HbVgHslEffect::HbVgHslEffect(HbVgHslEffectPrivate &dd, QObject *parent)

    : HbVgEffect(dd, parent)

{

}

HbVgHslEffect::~HbVgHslEffect()

{

}

qreal HbVgHslEffect::hue() const

{

    Q_D(const HbVgHslEffect);

    return d->hue;

}

void HbVgHslEffect::setHue(qreal hue)

{

    Q_D(HbVgHslEffect);

        return;

    d->hue = hue;

    updateEffect();

    emit hueChanged(hue);

}

qreal HbVgHslEffect::saturation() const

{

    Q_D(const HbVgHslEffect);

    return d->saturation;

}

void HbVgHslEffect::setSaturation(qreal saturation)

{

    Q_D(HbVgHslEffect);

        return;

    d->saturation = saturation;

    updateEffect();

    emit saturationChanged(saturation);

}

qreal HbVgHslEffect::lightness() const

{

    Q_D(const HbVgHslEffect);

    return d->lightness;

}

void HbVgHslEffect::setLightness(qreal lightness)

{

    Q_D(HbVgHslEffect);

        return;

    d->lightness = lightness;

    updateEffect();

    emit lightnessChanged(lightness);

}

void HbVgHslEffect::desaturate()

{

    setHue(0);

    setSaturation(0);

    setLightness(0);

}

QRectF HbVgHslEffect::boundingRectFor(const QRectF &rect) const

{

    return rect;

}

#ifdef HB_EFFECTS_OPENVG

inline void getSaturationRotationMatrix(VGfloat *effectMatrix, VGfloat opacity,

{

    const VGfloat as = 1.0f - saturation;

    const VGfloat o = opacity;

    const VGfloat ao = 1.0f - o;

    const VGfloat c = qCos(angle);

    const VGfloat s = qSin(angle);

    effectMatrix[3] = 0.0f;

    effectMatrix[7] = 0.0f;

    effectMatrix[11] = 0.0f;

    effectMatrix[12] = 0.0f;

    effectMatrix[13] = 0.0f;

    effectMatrix[14] = 0.0f;

    effectMatrix[15] = 1.0f;

}

const VGfloat Rw = 0.3086f;

const VGfloat Gw = 0.6094f;

const VGfloat Bw = 0.0820f;

inline void getSaturationMatrix(VGfloat *effectMatrix, VGfloat opacity, VGfloat saturation)

{

    const VGfloat as = 1.0f - saturation;

    const VGfloat o = opacity;

    const VGfloat ao = 1.0f - o;

    const VGfloat asRw = o * as * Rw;

    const VGfloat asGw = o * as * Gw;

    const VGfloat asBw = o * as * Bw;

    effectMatrix[0] = asRw + sa + ao;

    effectMatrix[1] = asRw;

    effectMatrix[2] = asRw;

    effectMatrix[3] = 0.0f;

    effectMatrix[4] = asGw;

    effectMatrix[5] = asGw + sa + ao;

    effectMatrix[6] = asGw;

    effectMatrix[7] = 0.0f;

    effectMatrix[8] = asBw;

    effectMatrix[9] = asBw;

    effectMatrix[10] = asBw + sa + ao;

    effectMatrix[11] = 0.0f;

    effectMatrix[12] = 0.0f;

    effectMatrix[13] = 0.0f;

    effectMatrix[14] = 0.0f;

    effectMatrix[15] = 1.0f;

}

inline void getRotationMatrix(VGfloat *effectMatrix, VGfloat opacity, VGfloat angle)

{

    const VGfloat o = opacity;

    const VGfloat ao = 1.0f - o;

    const VGfloat c = qCos(angle);

    const VGfloat s = qSin(angle);

    effectMatrix[3] =  0.0f;

    effectMatrix[7] =  0.0f;

    effectMatrix[11] = 0.0f;

    effectMatrix[12] = 0.0f;

    effectMatrix[13] = 0.0f;

    effectMatrix[14] = 0.0f;

    effectMatrix[15] = 1.0f;

}

inline void getIdentityMatrix(VGfloat *effectMatrix)

{

    effectMatrix[0] = 1.0f;

    effectMatrix[1] = 0.0f;

    effectMatrix[2] = 0.0f;

    effectMatrix[3] = 0.0f;

    effectMatrix[4] = 0.0f;

    effectMatrix[5] = 1.0f;

    effectMatrix[6] = 0.0f;

    effectMatrix[7] = 0.0f;

    effectMatrix[8] = 0.0f;

    effectMatrix[9] = 0.0f;

    effectMatrix[10] = 1.0f;

    effectMatrix[11] = 0.0f;

    effectMatrix[12] = 0.0f;

    effectMatrix[13] = 0.0f;

    effectMatrix[14] = 0.0f;

    effectMatrix[15] = 1.0f;

}

#endif // HB_EFFECTS_OPENVG

void HbVgHslEffect::performEffect(QPainter *painter,

{

#ifdef HB_EFFECTS_OPENVG

    QPixmap cachedPm = cached(vgImageSize);

    if (!cachedPm.isNull()) {

        painter->drawPixmap(offset, cachedPm);

        return;

    }

    Q_D(HbVgHslEffect);

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

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

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

    if (opacity > HBVG_EPSILON) {

        if (d->paramsChanged) {

            // a helpful constant

            const qreal radsPerDeg = 2.0f * (qreal) M_PI / 360.0f;

            const VGfloat o = (VGfloat) opacity;

            const VGfloat angle = (VGfloat) clamp(d->hue * radsPerDeg, 0.0f, 2.0f * (qreal) M_PI); // angle [0, 2*pi]

            const VGfloat saturation = (VGfloat) clamp(d->saturation, 0.0f, 100.0f); // saturation [0, N]

            const VGfloat lightness = (VGfloat) clamp(d->lightness, -1.0f, 1.0f); // lightness [-1, 1]

            // Note: lightness affects offset and not matrix so we don't bother optimising that.

            const bool enableSaturation  = (saturation < 1.0f - HBVG_EPSILON || saturation > 1.0f + HBVG_EPSILON);

            const bool enableHueRotation = (HBVG_EPSILON < angle && angle < (2.0f * (qreal) M_PI - HBVG_EPSILON));

            if (enableSaturation && enableHueRotation) {

                // contains SaturateT*PrerotationT*HuerotationT*PostrotationT*I*opacity+I*(1-opacity) matrices

                // --- ugly, but saves lot of operations in FPU.

                // note: there are plenty of redundancy in these calculations

                getSaturationRotationMatrix(&d->colorMatrix[0], o, saturation, angle);

            } else if (enableSaturation && !enableHueRotation) {

                // saturationT*I*opacity+I*(1 - opacity) matrix without hue rotation

                getSaturationMatrix(&d->colorMatrix[0], o, saturation);

                // PrerotationT*HuerotationT*PostrotationT*I*opacity+I*(1-opacity) matrices without saturation matrix

                getRotationMatrix(&d->colorMatrix[0], o, angle);

            } else {

                // identity matrix

                getIdentityMatrix(&d->colorMatrix[0]);

            }

            // colour component offsets

            d->colorMatrix[16] = lightness * o;

            d->colorMatrix[17] = lightness * o;

            d->colorMatrix[18] = lightness * o;

            d->colorMatrix[19] = 0.0f;

        }

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

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

        tryCache(d->dstPixmap);

    } else {

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

    }

#else

    Q_UNUSED(painter);

    Q_UNUSED(offset);

    Q_UNUSED(vgImage);

    Q_UNUSED(vgImageSize);

#endif

}