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

**

** 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 "hbvgmaskeffect_p.h"

#include "hbvgmaskeffect_p_p.h"

#include <QPainter>

#include <QPaintEngine>

#include <QPaintDevice>

/*!

 * \class HbVgMaskEffect

 *

 * \brief OpenVG-based mask effect.

 *

 * The mask effect can be used to make a rectangular area or an area

 * defined by a pixmap's alpha channel transparent. The opacity effect

 * parameter is ignored.

 *

 * \internal

 */

HbVgMaskEffectPrivate::HbVgMaskEffectPrivate()

    : maskRectIsInDeviceCoords(false), maskCallback(0)

{

}

HbVgMaskEffect::HbVgMaskEffect(QObject *parent)

    : HbVgEffect(*new HbVgMaskEffectPrivate, parent)

{

}

HbVgMaskEffect::HbVgMaskEffect(HbVgMaskEffectPrivate &dd, QObject *parent)

    : HbVgEffect(dd, parent)

{

}

HbVgMaskEffect::~HbVgMaskEffect()

{

}

/*!

 * Turns off masking. Any previously set mask pixmap or rectangle will not be

 * effective anymore.

 */

void HbVgMaskEffect::clear()

{

    Q_D(HbVgMaskEffect);

    d->mask = d->scaledMask = d->callbackResult = QPixmap();

    d->maskRect = QRectF();

    d->maskRectIsInDeviceCoords = false;

    d->maskCallback = 0;

    d->maskCallbackParam = 0;

}

/*!

 * Returns the mask pixmap set by the previous setMask() call.

 */

QPixmap HbVgMaskEffect::mask() const

{

    Q_D(const HbVgMaskEffect);

    return d->mask;

}

/*!

 * Returns the scaled version of the mask that was used during the previous

 * paint. Will return a null pixmap if no painting took place since the last

 * setMask() call.

 */

QPixmap HbVgMaskEffect::scaledMask() const

{

    Q_D(const HbVgMaskEffect);

    return d->scaledMask;

}

/*!

 * Sets the mask pixmap. Only the alpha channel is relevant. Pixels where alpha

 * is 0 will be set transparent. The pixmap is subject to scaling and therefore

 * distortion may occur. If this is not acceptable then use the callback

 * version. Any previously set mask pixmap or rectangle will not be effective

 * anymore.

 */

void HbVgMaskEffect::setMask(const QPixmap &mask)

{

    Q_D(HbVgMaskEffect);

    clear();

    d->mask = mask;

    updateEffect();

    emit maskChanged(mask);

}

/*!

 * Returns the currently set mask callback pointer.

 */

HbVgMaskEffect::MaskCallback HbVgMaskEffect::maskCallback() const

{

    Q_D(const HbVgMaskEffect);

    return d->maskCallback;

}

/*!

 * Returns the currently set custom parameter that will be passed to the

 * callback.

 */

void *HbVgMaskEffect::maskCallbackParam() const

{

    Q_D(const HbVgMaskEffect);

    return d->maskCallbackParam;

}

/*!

 * If the user of the API is able to generate a mask pixmap for a given size,

 * use this function instead of setMask(). The callback will be invoked during

 * painting to get the mask pixmap. It should return a pixmap that has a size

 * that is same as the size that has been passed to the callback. The effect

 * tries to reduce the number of calls by calling only when a new callback is

 * set or when the size of the source item is different than before. Any

 * previously set mask pixmap or rectangle will not be effective anymore.

 */

void HbVgMaskEffect::setMaskCallback(MaskCallback callback, void *param)

{

    Q_D(HbVgMaskEffect);

    if (d->maskCallback == callback)

        return;

    clear();

    d->maskCallback = callback;

    d->maskCallbackParam = param;

    updateEffect();

    emit maskCallbackChanged(callback);

}

/*!

 * Returns the mask rectangle set by the previous setMaskRect() call.

 */

QRectF HbVgMaskEffect::maskRect() const

{

    Q_D(const HbVgMaskEffect);

    return d->maskRectIsInDeviceCoords ? QRectF() : d->maskRect;

}

/*!

 * Returns the mask rectangle set by the previous setMaskDeviceRect() call.

 */

QRectF HbVgMaskEffect::maskDeviceRect() const

{

    Q_D(const HbVgMaskEffect);

    return d->maskRectIsInDeviceCoords ? d->maskRect : QRectF();

}

/*!

 * Sets the mask rectangle. The area defined by the rectangle will be made

 * transparent inside the source item. Any previously set mask pixmap or

 * rectangle will not be effective anymore.

 */

void HbVgMaskEffect::setMaskRect(const QRectF &rect)

{

    Q_D(HbVgMaskEffect);

    if (rect == d->maskRect && !d->maskRectIsInDeviceCoords)

        return;

    clear();

    d->maskRect = rect;

    d->maskRectIsInDeviceCoords = false;

    updateEffect();

    emit maskRectChanged(rect);

}

/*!

 * Similar to setMask() but the rectangle is assumed to be in device coordinates

 * (i.e. relative to the entire screen instead of the source item), meaning that

 * the source item will be clipped where it intersects with \a rect.

 */

void HbVgMaskEffect::setMaskDeviceRect(const QRectF &rect)

{

    Q_D(HbVgMaskEffect);

    if (rect == d->maskRect && d->maskRectIsInDeviceCoords)

        return;

    clear();

    d->maskRect = rect;

    d->maskRectIsInDeviceCoords = true;

    updateEffect();

    emit maskRectChanged(rect);

}

/*!

 * \reimp

 */

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

{

    return rect;

}

/*!

 * Returns the OpenVG Y coordinate for a rectangle with the given Qt Y

 * coordinate and height.

 *

 * \internal

 */

inline int toVgYH(int y, int h, QPaintDevice *pdev)

{

    return pdev->height() - 1 - y - h;

}

/*!

 * \reimp

 */

void HbVgMaskEffect::performEffect(QPainter *painter,

                                   const QPointF &offset,

                                   const QVariant &vgImage,

                                   const QSize &vgImageSize)

{

#ifdef HB_EFFECTS_OPENVG

    Q_UNUSED(vgImage);

    Q_D(HbVgMaskEffect);

    // Initialize scaledMask if the mask has changed or the size of the source

    // is different than before.

    if (!d->mask.isNull()) {

        if (d->scaledMask.isNull())

            d->scaledMask = d->mask;

        // Scale only when really needed, i.e. when the size is different than

        // before (or there is a new mask).

        if (d->scaledMask.size() != vgImageSize)

            d->scaledMask = d->mask.scaled(vgImageSize);

    }

    vgSeti(VG_MASKING, VG_TRUE);

    QPaintDevice *pdev = painter->paintEngine()->paintDevice();

    // Set the mask for the entire surface to 1 (i.e. nothing is transparent).

    vgMask(VG_INVALID_HANDLE, VG_FILL_MASK,

           0, 0, pdev->width(), pdev->height());

    // If there is a pixmap then use that, otherwise use the rectangle. If none

    // of these is set then try the callback, if that is not set either then

    // just draw the source normally.

    QPixmap *maskPtr = 0;

    int ox = (int) offset.x();

    int oy = (int) offset.y();

    if (d->scaledMask.isNull() && !d->maskRect.isNull()) {

        int x1 = (int) d->maskRect.x();

        int y1 = (int) d->maskRect.y();

        int w = (int) d->maskRect.width();

        int h = (int) d->maskRect.height();

        if (!d->maskRectIsInDeviceCoords) {

            x1 += ox;

            y1 += oy;

        }

        // Make the area defined by the rectangle transparent. Passing

        // VG_CLEAR_MASK results in writing 0 to the mask which results in

        // transparent pixels at that position.

        vgMask(VG_INVALID_HANDLE, VG_CLEAR_MASK,

               x1, toVgYH(y1, h, pdev),

               w, h);

    } else if (!d->scaledMask.isNull()) {

        maskPtr = &d->scaledMask;

    } else if (d->maskCallback) {

        // Invoke the callback but only if it has just been set or the size of

        // the source is different than before.

        if (d->callbackResult.isNull() || d->callbackResult.size() != vgImageSize)

            d->callbackResult = d->maskCallback(vgImageSize, d->maskCallbackParam);

        maskPtr = &d->callbackResult;

    }

    if (maskPtr) {

        int w = vgImageSize.width();

        int h = vgImageSize.height();

        // Will use the alpha channel from the image, alpha=0 => 0 in the mask

        // => transparent pixel, alpha=255 => 1 in the mask => opaque pixel.

        vgMask(qPixmapToVGImage(*maskPtr), VG_SET_MASK,

               ox, toVgYH(oy, h, pdev),

               w, h);

    }

    // Draw the source item with masking enabled.

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

    vgSeti(VG_MASKING, VG_FALSE);

#else

    Q_UNUSED(painter);

    Q_UNUSED(offset);

    Q_UNUSED(vgImage);

    Q_UNUSED(vgImageSize);

#endif

}