QRasterPaintEngine Class
The QRasterPaintEngine class enables hardware acceleration of painting operations in Qt for Embedded Linux. More...
| Header: | #include <QRasterPaintEngine> |
| qmake: | QT += gui |
| Since: | Qt 4.2 |
| Inherits: | QPaintEngineEx |
This class is under development and is subject to change.
Public Functions
| QRasterPaintEngine(QPaintDevice *device) | |
| virtual | ~QRasterPaintEngine() |
Reimplemented Public Functions
| virtual bool | begin(QPaintDevice *device) override |
| virtual void | drawEllipse(const QRectF &rect) override |
| virtual void | drawImage(const QRectF &r, const QImage &img, const QRectF &sr, Qt::ImageConversionFlags flags = Qt::AutoColor) override |
| virtual void | drawLines(const QLine *lines, int lineCount) override |
| virtual void | drawLines(const QLineF *lines, int lineCount) override |
| virtual void | drawPixmap(const QRectF &r, const QPixmap &pixmap, const QRectF &sr) override |
| virtual void | drawPoints(const QPointF *points, int pointCount) override |
| virtual void | drawPoints(const QPoint *points, int pointCount) override |
| virtual void | drawPolygon(const QPointF *points, int pointCount, QPaintEngine::PolygonDrawMode mode) override |
| virtual void | drawPolygon(const QPoint *points, int pointCount, QPaintEngine::PolygonDrawMode mode) override |
| virtual void | drawRects(const QRect *rects, int rectCount) override |
| virtual void | drawRects(const QRectF *rects, int rectCount) override |
| virtual void | drawStaticTextItem(QStaticTextItem *textItem) override |
| virtual void | drawTextItem(const QPointF &p, const QTextItem &textItem) override |
| virtual void | drawTiledPixmap(const QRectF &r, const QPixmap &pixmap, const QPointF &sr) override |
| virtual bool | end() override |
| virtual void | fillRect(const QRectF &r, const QBrush &brush) override |
| virtual void | fillRect(const QRectF &r, const QColor &color) override |
| virtual bool | shouldDrawCachedGlyphs(QFontEngine *fontEngine, const QTransform &m) const override |
| virtual QPaintEngine::Type | type() const override |
- 24 public functions inherited from QPaintEngine
Related Non-Members
| typedef | QSpan |
Detailed Description
The QRasterPaintEngine class enables hardware acceleration of painting operations in Qt for Embedded Linux.
Note that this functionality is only available in Qt for Embedded Linux.
In Qt for Embedded Linux, painting is a pure software implementation. But starting with Qt 4.2, it is possible to add an accelerated graphics driver to take advantage of available hardware resources.
Hardware acceleration is accomplished by creating a custom screen driver, accelerating the copying from memory to the screen, and implementing a custom paint engine accelerating the various painting operations. Then a custom paint device and a custom window surface must be implemented to make Qt for Embedded Linux aware of the accelerated driver.
Note: The QRasterPaintEngine class does not support 8-bit images. Instead, they need to be converted to a supported format, such as QImage::Format_ARGB32_Premultiplied.
See also QPaintEngine.
Member Function Documentation
QRasterPaintEngine::QRasterPaintEngine(QPaintDevice *device)
Creates a raster based paint engine for operating on the given device, with the complete set of paint engine features and capabilities.
This function was introduced in Qt 4.5.
[virtual] QRasterPaintEngine::~QRasterPaintEngine()
Destroys this paint engine.
[override virtual] bool QRasterPaintEngine::begin(QPaintDevice *device)
Reimplemented from QPaintEngine::begin().
[override virtual] void QRasterPaintEngine::drawEllipse(const QRectF &rect)
[override virtual] void QRasterPaintEngine::drawImage(const QRectF &r, const QImage &img, const QRectF &sr, Qt::ImageConversionFlags flags = Qt::AutoColor)
[override virtual] void QRasterPaintEngine::drawLines(const QLine *lines, int lineCount)
[override virtual] void QRasterPaintEngine::drawLines(const QLineF *lines, int lineCount)
[override virtual] void QRasterPaintEngine::drawPixmap(const QRectF &r, const QPixmap &pixmap, const QRectF &sr)
[override virtual] void QRasterPaintEngine::drawPoints(const QPointF *points, int pointCount)
[override virtual] void QRasterPaintEngine::drawPoints(const QPoint *points, int pointCount)
This is an overloaded function.
[override virtual] void QRasterPaintEngine::drawPolygon(const QPointF *points, int pointCount, QPaintEngine::PolygonDrawMode mode)
[override virtual] void QRasterPaintEngine::drawPolygon(const QPoint *points, int pointCount, QPaintEngine::PolygonDrawMode mode)
[override virtual] void QRasterPaintEngine::drawRects(const QRect *rects, int rectCount)
[override virtual] void QRasterPaintEngine::drawRects(const QRectF *rects, int rectCount)
[override virtual] void QRasterPaintEngine::drawStaticTextItem(QStaticTextItem *textItem)
[override virtual] void QRasterPaintEngine::drawTextItem(const QPointF &p, const QTextItem &textItem)
Reimplemented from QPaintEngine::drawTextItem().
[override virtual] void QRasterPaintEngine::drawTiledPixmap(const QRectF &r, const QPixmap &pixmap, const QPointF &sr)
[override virtual] bool QRasterPaintEngine::end()
Reimplemented from QPaintEngine::end().
[override virtual] void QRasterPaintEngine::fillRect(const QRectF &r, const QBrush &brush)
[override virtual] void QRasterPaintEngine::fillRect(const QRectF &r, const QColor &color)
[override virtual] bool QRasterPaintEngine::shouldDrawCachedGlyphs(QFontEngine *fontEngine, const QTransform &m) const
Indicates whether glyph caching is supported by the font engine fontEngine with the given transform m applied.
[override virtual] QPaintEngine::Type QRasterPaintEngine::type() const
Reimplemented from QPaintEngine::type().
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