demos/deform/pathdeform.html
author William Roberts <williamr@symbian.org>
Mon, 21 Jun 2010 22:38:13 +0100
branchGCC_SURGE
changeset 27 93b982ccede2
parent 0 1918ee327afb
permissions -rw-r--r--
Mark extraneous symbols as ABSENT (bug 3065)

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<h2>Vector deformation</h2>
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<p>This demo shows how to use advanced vector techniques to draw text 
using a <code>QPainterPath</code>.</p>

<p>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.</p>

<p>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
<code>QPainterPath::addText()</code> function.</p>

<p>The lens is drawn using a single call to <code>drawEllipse()</code>, using
a <code>QRadialGradient</code> 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.</p>

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