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authorSamuel Rødal <sroedal@trolltech.com>2009-10-14 13:50:44 (GMT)
committerSamuel Rødal <sroedal@trolltech.com>2009-10-15 08:51:21 (GMT)
commitae33eb787a8b0ff9b04f02b9c18bad0bf6736b7f (patch)
tree6b944ad3154f805204f62358d294f35e89e6d703 /src/gui/image
parent342a1233df813f00df475b713fa1c6252ee4dcd0 (diff)
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Optimized raster drop shadow filter to only blur alpha channel.
Reviewed-by: Gunnar
Diffstat (limited to 'src/gui/image')
-rw-r--r--src/gui/image/qpixmapfilter.cpp51
1 files changed, 27 insertions, 24 deletions
diff --git a/src/gui/image/qpixmapfilter.cpp b/src/gui/image/qpixmapfilter.cpp
index df445db..9fcf776 100644
--- a/src/gui/image/qpixmapfilter.cpp
+++ b/src/gui/image/qpixmapfilter.cpp
@@ -591,7 +591,7 @@ QRectF QPixmapBlurFilter::boundingRectFor(const QRectF &rect) const
// Blur the image according to the blur radius
// Based on exponential blur algorithm by Jani Huhtanen
// (maximum radius is set to 16)
-static QImage blurred(const QImage& image, const QRect& rect, int radius)
+static QImage blurred(const QImage& image, const QRect& rect, int radius, bool alphaOnly = false)
{
int tab[] = { 14, 10, 8, 6, 5, 5, 4, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2 };
int alpha = (radius < 1) ? 16 : (radius > 17) ? 1 : tab[radius-1];
@@ -606,47 +606,53 @@ static QImage blurred(const QImage& image, const QRect& rect, int radius)
int rgba[4];
unsigned char* p;
+ int i1 = 0;
+ int i2 = 3;
+
+ if (alphaOnly)
+ i1 = i2 = (QSysInfo::ByteOrder == QSysInfo::BigEndian ? 0 : 3);
+
for (int col = c1; col <= c2; col++) {
p = result.scanLine(r1) + col * 4;
- for (int i = 0; i < 4; i++)
+ for (int i = i1; i <= i2; i++)
rgba[i] = p[i] << 4;
p += bpl;
for (int j = r1; j < r2; j++, p += bpl)
- for (int i = 0; i < 4; i++)
+ for (int i = i1; i <= i2; i++)
p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
}
for (int row = r1; row <= r2; row++) {
p = result.scanLine(row) + c1 * 4;
- for (int i = 0; i < 4; i++)
+ for (int i = i1; i <= i2; i++)
rgba[i] = p[i] << 4;
p += 4;
for (int j = c1; j < c2; j++, p += 4)
- for (int i = 0; i < 4; i++)
+ for (int i = i1; i <= i2; i++)
p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
}
for (int col = c1; col <= c2; col++) {
p = result.scanLine(r2) + col * 4;
- for (int i = 0; i < 4; i++)
+ for (int i = i1; i <= i2; i++)
rgba[i] = p[i] << 4;
p -= bpl;
for (int j = r1; j < r2; j++, p -= bpl)
- for (int i = 0; i < 4; i++)
+ for (int i = i1; i <= i2; i++)
p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
}
for (int row = r1; row <= r2; row++) {
p = result.scanLine(row) + c2 * 4;
- for (int i = 0; i < 4; i++)
+ for (int i = i1; i <= i2; i++)
rgba[i] = p[i] << 4;
p -= 4;
for (int j = c1; j < c2; j++, p -= 4)
- for (int i = 0; i < 4; i++)
+ for (int i = i1; i <= i2; i++)
p[i] = (rgba[i] += ((p[i] << 4) - rgba[i]) * alpha / 16) >> 4;
}
@@ -892,11 +898,11 @@ class QPixmapDropShadowFilterPrivate : public QPixmapFilterPrivate
{
public:
QPixmapDropShadowFilterPrivate()
- : offset(8, 8), color(63, 63, 63, 180), blurFilter(new QPixmapBlurFilter) {}
+ : offset(8, 8), color(63, 63, 63, 180), radius(1) {}
QPointF offset;
QColor color;
- QPixmapBlurFilter *blurFilter;
+ int radius;
};
/*!
@@ -940,8 +946,6 @@ public:
QPixmapDropShadowFilter::QPixmapDropShadowFilter(QObject *parent)
: QPixmapFilter(*new QPixmapDropShadowFilterPrivate, DropShadowFilter, parent)
{
- Q_D(QPixmapDropShadowFilter);
- d->blurFilter->setRadius(1);
}
/*!
@@ -951,8 +955,6 @@ QPixmapDropShadowFilter::QPixmapDropShadowFilter(QObject *parent)
*/
QPixmapDropShadowFilter::~QPixmapDropShadowFilter()
{
- Q_D(QPixmapDropShadowFilter);
- delete d->blurFilter;
}
/*!
@@ -967,7 +969,7 @@ QPixmapDropShadowFilter::~QPixmapDropShadowFilter()
int QPixmapDropShadowFilter::blurRadius() const
{
Q_D(const QPixmapDropShadowFilter);
- return d->blurFilter->radius();
+ return d->radius;
}
/*!
@@ -982,7 +984,7 @@ int QPixmapDropShadowFilter::blurRadius() const
void QPixmapDropShadowFilter::setBlurRadius(int radius)
{
Q_D(QPixmapDropShadowFilter);
- d->blurFilter->setRadius(radius);
+ d->radius = radius;
}
/*!
@@ -1056,7 +1058,7 @@ QRectF QPixmapDropShadowFilter::boundingRectFor(const QRectF &rect) const
{
Q_D(const QPixmapDropShadowFilter);
- const qreal delta = qreal(d->blurFilter->radius() * 2);
+ const qreal delta = qreal(d->radius * 2);
qreal x1 = qMin(rect.left(), rect.left() + d->offset.x() - delta);
qreal y1 = qMin(rect.top(), rect.top() + d->offset.y() - delta);
qreal x2 = qMax(rect.right(), rect.right() + d->offset.x() + delta);
@@ -1079,24 +1081,25 @@ void QPixmapDropShadowFilter::draw(QPainter *p,
QPixmapDropShadowFilter *dropShadowFilter = static_cast<QPixmapDropShadowFilter*>(filter);
if (dropShadowFilter) {
dropShadowFilter->setColor(d->color);
- dropShadowFilter->setBlurRadius(d->blurFilter->radius());
+ dropShadowFilter->setBlurRadius(d->radius);
dropShadowFilter->setOffset(d->offset);
dropShadowFilter->draw(p, pos, px, src);
return;
}
- QImage tmp = src.isNull() ? px.toImage() : px.copy(src.toRect()).toImage();
- QPainter tmpPainter(&tmp);
+ QImage tmp = src.isNull() ? px.toImage() : px.copy(src.toAlignedRect()).toImage();
+
+ // blur the alpha channel
+ tmp = blurred(tmp, tmp.rect(), d->radius, true);
// blacken the image...
+ QPainter tmpPainter(&tmp);
tmpPainter.setCompositionMode(QPainter::CompositionMode_SourceIn);
tmpPainter.fillRect(0, 0, tmp.width(), tmp.height(), d->color);
tmpPainter.end();
- const QPixmap pixTmp = QPixmap::fromImage(tmp);
-
// draw the blurred drop shadow...
- d->blurFilter->draw(p, pos + d->offset, pixTmp);
+ p->drawImage(pos + d->offset, tmp);
// Draw the actual pixmap...
p->drawPixmap(pos, px, src);