From ae33eb787a8b0ff9b04f02b9c18bad0bf6736b7f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Samuel=20R=C3=B8dal?= Date: Wed, 14 Oct 2009 15:50:44 +0200 Subject: Optimized raster drop shadow filter to only blur alpha channel. Reviewed-by: Gunnar --- src/gui/image/qpixmapfilter.cpp | 51 ++++++++++++++++++++++------------------- 1 file changed, 27 insertions(+), 24 deletions(-) diff --git a/src/gui/image/qpixmapfilter.cpp b/src/gui/image/qpixmapfilter.cpp index df445db53a..9fcf77694e 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(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); -- cgit v1.2.3