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QPixmap QPixmap::scaled ( const QSize & size, Qt::AspectRatioMode aspectRatioMode = Qt::IgnoreAspectRatio, Qt::TransformationMode transformMode = Qt::FastTransformation ) const
Scales the pixmap to the given size, using the aspect ratio and transformation modes specified by aspectRatioMode and transformMode.
If aspectRatioMode is Qt::IgnoreAspectRatio, the pixmap is scaled to size.
If aspectRatioMode is Qt::KeepAspectRatio, the pixmap is scaled to a rectangle as large as possible inside size, preserving the aspect ratio.
If aspectRatioMode is Qt::KeepAspectRatioByExpanding, the pixmap is scaled to a rectangle as small as possible outside size, preserving the aspect ratio.
If the given size is empty, this function returns a null pixmap.
In some cases it can be more beneficial to draw the pixmap to a painter with a scale set rather than scaling the pixmap. This is the case when the painter is for instance based on OpenGL or when the scale factor changes rapidly.
