/****************************************************************************
**
** 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 "hbvgblureffect_p.h"
#include "hbvgblureffect_p_p.h"
#include <QPainter>

/*!
 * \class HbVgBlurEffect
 *
 * \brief OpenVG-based blur filter effect.
 *
 * \internal
 */

HbVgBlurEffectPrivate::HbVgBlurEffectPrivate()
    : radius(0, 0)
{
}

HbVgBlurEffect::HbVgBlurEffect(QObject *parent)
    : HbVgEffect(*new HbVgBlurEffectPrivate, parent)
{
}

HbVgBlurEffect::HbVgBlurEffect(HbVgBlurEffectPrivate &dd, QObject *parent)
    : HbVgEffect(dd, parent)
{
}

HbVgBlurEffect::~HbVgBlurEffect()
{
}

QPointF HbVgBlurEffect::radius() const
{
    Q_D(const HbVgBlurEffect);
    return d->radius;
}

void HbVgBlurEffect::setRadius(const QPointF &radius)
{
    Q_D(HbVgBlurEffect);
    if (d->radius == radius) {
        return;
    }
    d->radius = radius;
    updateEffectBoundingRect();
    emit radiusChanged(radius);
}

QRectF HbVgBlurEffect::boundingRectFor(const QRectF &rect) const
{
    Q_D(const HbVgBlurEffect);
    QSizeF mappedRadius = d->mapSize(QSizeF(d->radius.x() + 2, d->radius.y() + 2));
    qreal deltaX = mappedRadius.width();
    qreal deltaY = mappedRadius.height();
    return rect.adjusted(-deltaX, -deltaY, deltaX, deltaY);
}

#ifdef HB_EFFECTS_OPENVG
// identity mapping of colour components (i.e. 0->0, 1->1, ..., 255->255)
VGubyte identityLUT[256] = {
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,
    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F,
    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
    0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F,
    0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F,
    0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F,
    0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E, 0x7F,
    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F,
    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F,
    0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5, 0xA6, 0xA7, 0xA8, 0xA9, 0xAA, 0xAB, 0xAC, 0xAD, 0xAE, 0xAF,
    0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7, 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF,
    0xC0, 0xC1, 0xC2, 0xC3, 0xC4, 0xC5, 0xC6, 0xC7, 0xC8, 0xC9, 0xCA, 0xCB, 0xCC, 0xCD, 0xCE, 0xCF,
    0xD0, 0xD1, 0xD2, 0xD3, 0xD4, 0xD5, 0xD6, 0xD7, 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF,
    0xE0, 0xE1, 0xE2, 0xE3, 0xE4, 0xE5, 0xE6, 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE, 0xEF,
    0xF0, 0xF1, 0xF2, 0xF3, 0xF4, 0xF5, 0xF6, 0xF7, 0xF8, 0xF9, 0xFA, 0xFB, 0xFC, 0xFD, 0xFE, 0xFF
};
#endif

QPixmap HbVgBlurEffect::makeBlur(const QVariant &vgImage, const QSize &vgImageSize)
{
#ifdef HB_EFFECTS_OPENVG
    QPixmap cachedPm = cached(vgImageSize);
    if (!cachedPm.isNull()) {
        return cachedPm;
    }

    Q_D(HbVgBlurEffect);
    VGImage srcImage = vgImage.value<VGImage>();
    VGImage dstImage = d->ensurePixmap(&d->dstPixmap, vgImageSize);
    QSizeF mappedRadius = d->mapSize(QSizeF(d->radius.x(), d->radius.y()));
    const VGfloat blurX = (VGfloat) clamp(mappedRadius.width(), HBVG_EPSILON, 16.0f);
    const VGfloat blurY = (VGfloat) clamp(mappedRadius.height(), HBVG_EPSILON, 16.0f);
    const VGfloat opacity = (VGfloat) clamp(d->opacity, 0.0f, 1.0f);
    if (opacity < 1.0f - HBVG_EPSILON) {
        VGImage tmpImage = d->ensurePixmap(&d->tmpPixmap, vgImageSize);
        vgGaussianBlur(tmpImage, srcImage, blurX, blurY, VG_TILE_PAD);
        if (d->paramsChanged) {
            for (int i = 0; i < 256; ++i) {
                d->alphaLUT[i] = (VGubyte)(i * opacity);
            }
        }
        vgLookup(dstImage, tmpImage,
                 identityLUT, identityLUT, identityLUT, d->alphaLUT,
                 VG_TRUE, VG_FALSE);
    } else {
        vgGaussianBlur(dstImage, srcImage, blurX, blurY, VG_TILE_PAD);
    }

    tryCache(d->dstPixmap);
    return d->dstPixmap;
#else
    Q_UNUSED(vgImage);
    Q_UNUSED(vgImageSize);
    return QPixmap();
#endif
}

void HbVgBlurEffect::performEffect(QPainter *painter,
                                   const QPointF &offset,
                                   const QVariant &vgImage,
                                   const QSize &vgImageSize)
{
#ifdef HB_EFFECTS_OPENVG
    QPixmap blurred = makeBlur(vgImage, vgImageSize);
    painter->drawPixmap(offset, blurred);
#else
    Q_UNUSED(painter);
    Q_UNUSED(offset);
    Q_UNUSED(vgImage);
    Q_UNUSED(vgImageSize);
#endif
}
