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Vector deformation
This demo shows how to use advanced vector techniques to draw text
using a QPainterPath.
We define a vector deformation field in the shape of a lens and apply
this to all points in a path. This means that what is rendered on
screen is not pixel manipulation, but modified vector representations of
the glyphs themselves. This is visible from the high quality of the
antialiased edges for the deformed glyphs.
To get a fairly complex path we allow the user to type in text and
convert the text to paths. This is done using the
QPainterPath::addText() function.
The lens is drawn using a single call to drawEllipse(), using
a QRadialGradient to fill it with a specialized color table,
giving the effect of the Sun's reflection and a drop shadow. The lens
is cached as a pixmap for better performance.