diff options
Diffstat (limited to 'src/gui/painting/qpainter.cpp')
| -rw-r--r-- | src/gui/painting/qpainter.cpp | 144 |
1 files changed, 131 insertions, 13 deletions
diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp index ab5773e..2502cc0 100644 --- a/src/gui/painting/qpainter.cpp +++ b/src/gui/painting/qpainter.cpp @@ -1,6 +1,6 @@ /**************************************************************************** ** -** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). ** All rights reserved. ** Contact: Nokia Corporation (qt-info@nokia.com) ** @@ -285,7 +285,7 @@ bool QPainterPrivate::attachPainterPrivate(QPainter *q, QPaintDevice *pdev) // Update matrix. if (q->d_ptr->state->WxF) { - q->d_ptr->state->redirectionMatrix *= q->d_ptr->state->worldMatrix; + q->d_ptr->state->redirectionMatrix = q->d_ptr->state->matrix; q->d_ptr->state->redirectionMatrix.translate(-offset.x(), -offset.y()); q->d_ptr->state->worldMatrix = QTransform(); q->d_ptr->state->WxF = false; @@ -1318,6 +1318,87 @@ void QPainterPrivate::updateState(QPainterState *newState) Another workaround is to convert the paths to polygons first and then draw the polygons instead. + \section1 Performance + + QPainter is a rich framework that allows developers to do a great + variety of graphical operations, such as gradients, composition + modes and vector graphics. And QPainter can do this across a + variety of different hardware and software stacks. Naturally the + underlying combination of hardware and software has some + implications for performance, and ensuring that every single + operation is fast in combination with all the various combinations + of composition modes, brushes, clipping, transformation, etc, is + close to an impossible task because of the number of + permutations. As a compromise we have selected a subset of the + QPainter API and backends, where performance is guaranteed to be as + good as we can sensibly get it for the given combination of + hardware and software. + + The backends we focus on as high-performance engines are: + + \list + + \o Raster - This backend implements all rendering in pure software + and is always used to render into QImages. For optimal performance + only use the format types QImage::Format_ARGB32_Premultiplied, + QImage::Format_RGB32 or QImage::Format_RGB16. Any other format, + including QImage::Format_ARGB32, has significantly worse + performance. This engine is also used by default on Windows and on + QWS. It can be used as default graphics system on any + OS/hardware/software combination by passing \c {-graphicssystem + raster} on the command line + + \o OpenGL 2.0 (ES) - This backend is the primary backend for + hardware accelerated graphics. It can be run on desktop machines + and embedded devices supporting the OpenGL 2.0 or OpenGL/ES 2.0 + specification. This includes most graphics chips produced in the + last couple of years. The engine can be enabled by using QPainter + onto a QGLWidget or by passing \c {-graphicssystem opengl} on the + command line when the underlying system supports it. + + \o OpenVG - This backend implements the Khronos standard for 2D + and Vector Graphics. It is primarily for embedded devices with + hardware support for OpenVG. The engine can be enabled by + passing \c {-graphicssystem openvg} on the command line when + the underlying system supports it. + + \endlist + + These operations are: + + \list + + \o Simple transformations, meaning translation and scaling, pluss + 0, 90, 180, 270 degree rotations. + + \o \c drawPixmap() in combination with simple transformations and + opacity with non-smooth transformation mode + (\c QPainter::SmoothPixmapTransform not enabled as a render hint). + + \o Rectangle fills with solid color, two-color linear gradients + and simple transforms. + + \o Rectangular clipping with simple transformations and intersect + clip. + + \o Composition Modes \c QPainter::CompositionMode_Source and + QPainter::CompositionMode_SourceOver + + \o Rounded rectangle filling using solid color and two-color + linear gradients fills. + + \o 3x3 patched pixmaps, via qDrawBorderPixmap. + + \endlist + + This list gives an indication of which features to safely use in + an application where performance is critical. For certain setups, + other operations may be fast too, but before making extensive use + of them, it is recommended to benchmark and verify them on the + system where the software will run in the end. There are also + cases where expensive operations are ok to use, for instance when + the result is cached in a QPixmap. + \sa QPaintDevice, QPaintEngine, {QtSvg Module}, {Basic Drawing Example}, {Drawing Utility Functions} */ @@ -1901,9 +1982,14 @@ QPaintEngine *QPainter::paintEngine() const /*! \since 4.6 - Flushes the painting pipeline and prepares for the user issuing - commands directly to the underlying graphics context. Must be - followed by a call to endNativePainting(). + Flushes the painting pipeline and prepares for the user issuing commands + directly to the underlying graphics context. Must be followed by a call to + endNativePainting(). + + Note that only the states the underlying paint engine changes will be reset + to their respective default states. If, for example, the OpenGL polygon + mode is changed by the user inside a beginNativePaint()/endNativePainting() + block, it will not be reset to the default state by endNativePainting(). Here is an example that shows intermixing of painter commands and raw OpenGL commands: @@ -1927,9 +2013,9 @@ void QPainter::beginNativePainting() /*! \since 4.6 - Restores the painter after manually issuing native painting commands. - Lets the painter restore any native state that it relies on before - calling any other painter commands. + Restores the painter after manually issuing native painting commands. Lets + the painter restore any native state that it relies on before calling any + other painter commands. \sa beginNativePainting() */ @@ -5919,7 +6005,7 @@ static QPixmap generateWavyPixmap(qreal maxRadius, const QPen &pen) if (QPixmapCache::find(key, pixmap)) return pixmap; - const qreal halfPeriod = qMax(qreal(2), radiusBase * qreal(1.61803399)); // the golden ratio + const qreal halfPeriod = qMax(qreal(2), qreal(radiusBase * 1.61803399)); // the golden ratio const int width = qCeil(100 / (2 * halfPeriod)) * (2 * halfPeriod); const int radius = qFloor(radiusBase); @@ -7297,10 +7383,15 @@ struct QPaintDeviceRedirection typedef QList<QPaintDeviceRedirection> QPaintDeviceRedirectionList; Q_GLOBAL_STATIC(QPaintDeviceRedirectionList, globalRedirections) Q_GLOBAL_STATIC(QMutex, globalRedirectionsMutex) +Q_GLOBAL_STATIC(QAtomicInt, globalRedirectionAtomic) /*! \threadsafe + \obsolete + + Please use QWidget::render() instead. + Redirects all paint commands for the given paint \a device, to the \a replacement device. The optional point \a offset defines an offset within the source device. @@ -7310,9 +7401,10 @@ Q_GLOBAL_STATIC(QMutex, globalRedirectionsMutex) device's painter (if any) before redirecting. Call restoreRedirected() to restore the previous redirection. - In general, you'll probably find that calling - QPixmap::grabWidget() or QPixmap::grabWindow() is an easier - solution. + \warning Making use of redirections in the QPainter API implies + that QPainter::begin() and QPaintDevice destructors need to hold + a mutex for a short period. This can impact performance. Use of + QWidget::render is strongly encouraged. \sa redirected(), restoreRedirected() */ @@ -7344,14 +7436,24 @@ void QPainter::setRedirected(const QPaintDevice *device, Q_ASSERT(redirections != 0); *redirections += QPaintDeviceRedirection(device, rdev ? rdev : replacement, offset + roffset, hadInternalWidgetRedirection ? redirections->size() - 1 : -1); + globalRedirectionAtomic()->ref(); } /*! \threadsafe + \obsolete + + Using QWidget::render() obsoletes the use of this function. + Restores the previous redirection for the given \a device after a call to setRedirected(). + \warning Making use of redirections in the QPainter API implies + that QPainter::begin() and QPaintDevice destructors need to hold + a mutex for a short period. This can impact performance. Use of + QWidget::render is strongly encouraged. + \sa redirected() */ void QPainter::restoreRedirected(const QPaintDevice *device) @@ -7362,6 +7464,7 @@ void QPainter::restoreRedirected(const QPaintDevice *device) Q_ASSERT(redirections != 0); for (int i = redirections->size()-1; i >= 0; --i) { if (redirections->at(i) == device) { + globalRedirectionAtomic()->deref(); const int internalWidgetRedirectionIndex = redirections->at(i).internalWidgetRedirectionIndex; redirections->removeAt(i); // Restore the internal widget redirection, i.e. remove it from the global @@ -7383,9 +7486,18 @@ void QPainter::restoreRedirected(const QPaintDevice *device) /*! \threadsafe + \obsolete + + Using QWidget::render() obsoletes the use of this function. + Returns the replacement for given \a device. The optional out parameter \a offset returns the offset within the replaced device. + \warning Making use of redirections in the QPainter API implies + that QPainter::begin() and QPaintDevice destructors need to hold + a mutex for a short period. This can impact performance. Use of + QWidget::render is strongly encouraged. + \sa setRedirected(), restoreRedirected() */ QPaintDevice *QPainter::redirected(const QPaintDevice *device, QPoint *offset) @@ -7398,6 +7510,9 @@ QPaintDevice *QPainter::redirected(const QPaintDevice *device, QPoint *offset) return widgetPrivate->redirected(offset); } + if (*globalRedirectionAtomic() == 0) + return 0; + QMutexLocker locker(globalRedirectionsMutex()); QPaintDeviceRedirectionList *redirections = globalRedirections(); Q_ASSERT(redirections != 0); @@ -7415,6 +7530,9 @@ QPaintDevice *QPainter::redirected(const QPaintDevice *device, QPoint *offset) void qt_painter_removePaintDevice(QPaintDevice *dev) { + if (*globalRedirectionAtomic() == 0) + return; + QMutex *mutex = 0; QT_TRY { mutex = globalRedirectionsMutex(); @@ -7631,7 +7749,7 @@ start_lengthVariant: // in the paint engines when drawing on floating point offsets const qreal scale = painter->transform().m22(); if (scale != 0) - yoff = qRound(yoff * scale) / scale; + yoff = -qRound(-yoff * scale) / scale; } } } |