| author | eckhart.koppen@nokia.com |
| Wed, 31 Mar 2010 11:06:36 +0300 | |
| changeset 7 | f7bc934e204c |
| permissions | -rw-r--r-- |
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eckhart.koppen@nokia.com
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<html> |
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<center> |
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<h2>Vector deformation</h2> |
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</center> |
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eckhart.koppen@nokia.com
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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<p>This demo shows how to use advanced vector techniques to draw text |
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eckhart.koppen@nokia.com
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using a <code>QPainterPath</code>.</p> |
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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<p>We define a vector deformation field in the shape of a lens and apply |
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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this to all points in a path. This means that what is rendered on |
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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screen is not pixel manipulation, but modified vector representations of |
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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the glyphs themselves. This is visible from the high quality of the |
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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antialiased edges for the deformed glyphs.</p> |
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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<p>To get a fairly complex path we allow the user to type in text and |
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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convert the text to paths. This is done using the |
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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<code>QPainterPath::addText()</code> function.</p> |
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f7bc934e204c
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eckhart.koppen@nokia.com
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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<p>The lens is drawn using a single call to <code>drawEllipse()</code>, using |
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eckhart.koppen@nokia.com
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a <code>QRadialGradient</code> to fill it with a specialized color table, |
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f7bc934e204c
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eckhart.koppen@nokia.com
parents:
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giving the effect of the Sun's reflection and a drop shadow. The lens |
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f7bc934e204c
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eckhart.koppen@nokia.com
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is cached as a pixmap for better performance.</p> |
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f7bc934e204c
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eckhart.koppen@nokia.com
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f7bc934e204c
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eckhart.koppen@nokia.com
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</html> |