/****************************************************************************
**
** 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
}