内容

• 公共函数
• 重实现公共函数
• 相关非成员
• 详细描述

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。

• 所有成员列表，包括继承成员

公共函数

	QRasterPaintEngine (QPaintDevice * device )
virtual	~QRasterPaintEngine ()

重实现公共函数

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 公共函数继承自 QPaintEngine

相关非成员

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。

[virtual] QRasterPaintEngine:: ~QRasterPaintEngine ()

销毁此描绘引擎。

[override virtual] bool QRasterPaintEngine:: begin ( QPaintDevice * device )

重实现自 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 )

这是重载函数。

[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 )

重实现自 QPaintEngine::drawTextItem ().

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

[override virtual] bool QRasterPaintEngine:: end ()

重实现自 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

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).