QRasterPaintEngine 类

The QRasterPaintEngine class enables hardware acceleration of painting operations in Qt for Embedded Linux. 更多...

头: #include <QRasterPaintEngine>
qmake: QT += gui
Since: Qt 4.2
继承: QPaintEngineEx

该类在开发且可能改变。

公共函数

QRasterPaintEngine (QPaintDevice * device )
~QRasterPaintEngine ()

重实现公共函数

virtual bool begin (QPaintDevice * device )
virtual void drawEllipse (const QRectF & rect )
virtual void drawImage (const QRectF & r , const QImage & img , const QRectF & sr , Qt::ImageConversionFlags flags = Qt::AutoColor)
virtual void drawLines (const QLine * lines , int lineCount )
virtual void drawLines (const QLineF * lines , int lineCount )
virtual void drawPixmap (const QRectF & r , const QPixmap & pixmap , const QRectF & sr )
virtual void drawPoints (const QPointF * points , int pointCount )
virtual void drawPoints (const QPoint * points , int pointCount )
virtual void drawPolygon (const QPointF * points , int pointCount , PolygonDrawMode mode )
virtual void drawPolygon (const QPoint * points , int pointCount , PolygonDrawMode mode )
virtual void drawRects (const QRect * rects , int rectCount )
virtual void drawRects (const QRectF * rects , int rectCount )
virtual void drawStaticTextItem (QStaticTextItem * textItem )
virtual void drawTextItem (const QPointF & p , const QTextItem & textItem )
virtual void drawTiledPixmap (const QRectF & r , const QPixmap & pixmap , const QPointF & sr )
virtual bool end ()
virtual void fillRect (const QRectF & r , const QBrush & brush )
virtual void fillRect (const QRectF & r , const QColor & color )
virtual bool shouldDrawCachedGlyphs (QFontEngine * fontEngine , const QTransform & m ) const
virtual Type type () const
typedef QSpan

详细描述

The QRasterPaintEngine class enables hardware acceleration of painting operations in Qt for Embedded Linux.

注意:此功能仅用于 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.

注意: 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 .

另请参阅 QPaintEngine .

成员函数文档编制

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 .

该函数在 Qt 4.5 引入。

QRasterPaintEngine:: ~QRasterPaintEngine ()

销毁此描绘引擎。

[虚拟] bool QRasterPaintEngine:: begin ( QPaintDevice * device )

重实现自 QPaintEngine::begin ().

[虚拟] void QRasterPaintEngine:: drawEllipse (const QRectF & rect )

重实现自 QPaintEngine::drawEllipse ().

[虚拟] void QRasterPaintEngine:: drawImage (const QRectF & r , const QImage & img , const QRectF & sr , Qt::ImageConversionFlags flags = Qt::AutoColor)

重实现自 QPaintEngine::drawImage ().

[虚拟] void QRasterPaintEngine:: drawLines (const QLine * lines , int lineCount )

重实现自 QPaintEngine::drawLines ().

[虚拟] void QRasterPaintEngine:: drawLines (const QLineF * lines , int lineCount )

重实现自 QPaintEngine::drawLines ().

[虚拟] void QRasterPaintEngine:: drawPixmap (const QRectF & r , const QPixmap & pixmap , const QRectF & sr )

重实现自 QPaintEngine::drawPixmap ().

[虚拟] void QRasterPaintEngine:: drawPoints (const QPointF * points , int pointCount )

重实现自 QPaintEngine::drawPoints ().

[虚拟] void QRasterPaintEngine:: drawPoints (const QPoint * points , int pointCount )

重实现自 QPaintEngine::drawPoints ().

这是重载函数。

[虚拟] void QRasterPaintEngine:: drawPolygon (const QPointF * points , int pointCount , PolygonDrawMode mode )

重实现自 QPaintEngine::drawPolygon ().

[虚拟] void QRasterPaintEngine:: drawPolygon (const QPoint * points , int pointCount , PolygonDrawMode mode )

重实现自 QPaintEngine::drawPolygon ().

[虚拟] void QRasterPaintEngine:: drawRects (const QRect * rects , int rectCount )

重实现自 QPaintEngine::drawRects ().

[虚拟] void QRasterPaintEngine:: drawRects (const QRectF * rects , int rectCount )

重实现自 QPaintEngine::drawRects ().

[虚拟] void QRasterPaintEngine:: drawStaticTextItem ( QStaticTextItem * textItem )

[虚拟] void QRasterPaintEngine:: drawTextItem (const QPointF & p , const QTextItem & textItem )

重实现自 QPaintEngine::drawTextItem ().

[虚拟] void QRasterPaintEngine:: drawTiledPixmap (const QRectF & r , const QPixmap & pixmap , const QPointF & sr )

重实现自 QPaintEngine::drawTiledPixmap ().

[虚拟] bool QRasterPaintEngine:: end ()

重实现自 QPaintEngine::end ().

[虚拟] void QRasterPaintEngine:: fillRect (const QRectF & r , const QBrush & brush )

[虚拟] void QRasterPaintEngine:: fillRect (const QRectF & r , const QColor & color )

[虚拟] 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.

[虚拟] Type QRasterPaintEngine:: type () const

重实现自 QPaintEngine::type ().

相关非成员

typedef QSpan

A struct equivalent to QT_FT_Span, containing a position (x, y), the span's length in pixels and its color/coverage (a value ranging from 0 to 255).